Grounding and Electromagnetic Compatibility of PLC Systems

Grounding and Electromagnetic Compatibility of PLC Systems
Grounding and
Electromagnetic Compatibility
of PLC Systems
Basic Principles and Measures
User Manual
33002439.01
September 2004
2
Document Set
Document Set
Presentation
l Quantum Hardware Reference Manual: UNY USE 10010 V20E
l Premium Hardware Reference Manual: UNY USE 20110 V20E
3
Document Set
4
Table of Contents
About the Book . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Part I Regulations and Standards. . . . . . . . . . . . . . . . . . . . . . . 15
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Chapter 1
Using Regulations and Standards in the EU . . . . . . . . . . . . . . 17
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Harmonized Regulations and Standards in the EU. . . . . . . . . . . . . . . . . . . . . . .
EMC Directives in the EU . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Machine Directives in the EU . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Low Voltage Directive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
How to find EU guidelines and harmonized standards . . . . . . . . . . . . . . . . . . . .
Chapter 2
17
18
21
22
23
24
International Standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Role of the Standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
International Standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Relevant Standards for PLC System Users . . . . . . . . . . . . . . . . . . . . . . . . . . . .
25
26
27
28
Part II Grounding and Electromagnetic Compatibility
(EMC) - Basics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Chapter 3
Grounding - Basics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Definitions: Earth, ground, reference conductor system . . . . . . . . . . . . . . . . . . .
Ground Connections in TT, TN and IT Alternating Current Systems . . . . . . . . .
Personal Danger through Electrical Current . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Electric Shock: Causes and preventative measures . . . . . . . . . . . . . . . . . . . . . .
Classes of Protection for Electrical Equipment . . . . . . . . . . . . . . . . . . . . . . . . . .
Protective Earth. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
33
34
36
38
39
41
42
5
Chapter 4
4.1
4.2
4.3
Chapter 5
Electromagnetic Disturbance and EMC . . . . . . . . . . . . . . . . . . 45
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Results, Causes and Types of Disturbance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Results of Disturbance to an Industrial Application . . . . . . . . . . . . . . . . . . . . . . . 48
Principles of Interference Influence - Influence Model . . . . . . . . . . . . . . . . . . . . . 49
Sources of Interference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Interference Variables and Interference Signals . . . . . . . . . . . . . . . . . . . . . . . . . 53
Effective Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
Overlapping of Interference and Useful Signals on Wires . . . . . . . . . . . . . . . . . . 57
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
Symmetrically and Asymmetrically Operated Circuits . . . . . . . . . . . . . . . . . . . . . 58
Differential Mode Interference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
Common Mode Interference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
Common Mode-Differential Mode-Conversion. . . . . . . . . . . . . . . . . . . . . . . . . . . 62
Interference Coupling. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
Interference Coupling Mechanisms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
Galvanic Coupling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
Inductive Coupling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
Capacitive Coupling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
Radiating Coupling. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
Wave Influence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
Which measures for which type of coupling?. . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
Basic EMC Measures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
EMC Measures for Grounding Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
EMC Compatible Wiring. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
Balancing Circuits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
Transposition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
Room Arrangements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
Cabling Arrangements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
Shielding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
Filtering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86
6
Part III Earth and EMC Measures in Automation Systems System Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
Chapter 6
Measures for the Entire System . . . . . . . . . . . . . . . . . . . . . . . . 91
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Measures to take at Sources of Interference . . . . . . . . . . . . . . . . . . . . . . . . . . .
Guidelines for Arranging Devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Protection against Electrostatic Discharge . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Chapter 7
91
92
92
93
Grounding, Earthing and Lightning Protection System . . . . . 95
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
Combination of Earthing, Grounding and Lightning Protection
and Highest Safety Requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
Guidelines for the Grounding System in Buildings . . . . . . . . . . . . . . . . . . . . . . . 98
Guidelines for Local Grounding for Devices and Machines . . . . . . . . . . . . . . . 100
Guidelines for Installing an Island Grounding System. . . . . . . . . . . . . . . . . . . . 101
Guidelines for the Earthing System and Grounding System . . . . . . . . . . . . . . . 103
Guidelines for Lightning and Overvoltage Protection . . . . . . . . . . . . . . . . . . . . 106
Guidelines for Grounding and Earthing for Systems between Buildings. . . . . . 108
Guidelines for Creating Ground Connections . . . . . . . . . . . . . . . . . . . . . . . . . . 109
Chapter 8
Power Supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115
How to Plan the Power Supply Plant. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116
Guidelines for the Power Supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117
Chapter 9
Cabinets and Machines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Guidelines for Arranging the Device in the Cabinet or a Machine. . . . . . . . . . .
Guidelines for Grounding and Earthing in the Cabinet . . . . . . . . . . . . . . . . . . .
Guidelines for the Reference Conductor System in the Cabinet. . . . . . . . . . . .
Guidelines for Cabling in the Cabinet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Guidelines for Materials and Lighting in the Cabinet. . . . . . . . . . . . . . . . . . . . .
Guidelines for Installing Filters in the Cabinet . . . . . . . . . . . . . . . . . . . . . . . . . .
119
120
122
125
126
127
128
7
Chapter 10
Cabling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131
Classification of Signals according to their EMC Performance . . . . . . . . . . . . . 132
Guidelines for Selecting Cables. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133
Guidelines for Combining Signals in Cables, Conductor Bundles
and Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134
Guidelines for Laying Cables in Parallel and Crossing Cables . . . . . . . . . . . . . 135
Guidelines for Creating the Ground Connection for Cable Shielding. . . . . . . . . 136
Guidelines for Grounding Unused Conductors . . . . . . . . . . . . . . . . . . . . . . . . . 139
Guidelines for Installing Cables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139
Guidelines for Cable Ducts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141
Guidelines for Cables between Buildings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144
Part IV Quantum Family. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145
Chapter 11
Quantum Family . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147
Batteries as DC power supplies. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148
General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149
AC Power and Grounding Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150
DC Power and Grounding Considerations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155
Closed System Installation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160
Part V Momentum Family . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163
Chapter 12
Momentum Family . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165
Structuring Your Power Supply System. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166
Selecting Power Supplies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167
Single Power Supply Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 168
Protective Circuits for DC Actuators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 170
Protective Circuits for AC Actuators. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171
Suggested Component Values for AC and DC Actuators . . . . . . . . . . . . . . . . . 172
Grounding Momentum Devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 172
Grounding DIN Rail Terminals and Cabinets. . . . . . . . . . . . . . . . . . . . . . . . . . . 174
Grounding Analog I/O Lines. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175
8
Part VI Premium Family . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177
Chapter 13
Standards Conformity and EMC Characteristics. . . . . . . . . . 179
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179
Standards and Certification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180
Operating conditions and environmental conditions to be avoided . . . . . . . . . . 181
Chapter 14
Basic elements: Backplane RKY, power supply PSY . . . . . . 189
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Connection of the ground to a RKY rack. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
How to mount processor modules. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Precautions to be taken when replacing a PCX 57 processor . . . . . . . . . . . . .
Rules for connecting PSY supply modules . . . . . . . . . . . . . . . . . . . . . . . . . . .
Connecting alternating current power supply modules . . . . . . . . . . . . . . . . . . .
Connecting direct current power supply modules from
an alternating current network. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Chapter 15
203
204
206
208
211
213
217
Discrete I/O Modules DEY/DSY . . . . . . . . . . . . . . . . . . . . . . . . 219
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Choice of direct current power supply for sensors and
pre-actuators associated with Discrete I/O modules. . . . . . . . . . . . . . . . . . . . .
Precautions and general rules for wiring with Discrete I/O modules . . . . . . . . .
Means of connecting Discrete I/O modules:
connecting HE10 connector modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Means of connecting Discrete I/O modules:
connecting screw terminal block modules. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Ways of connecting discrete I/O modules:
connecting modules to TELEFAST interfaces using an HE10 connector . . . . .
Chapter 17
198
Power Supply for the Process and AS-i SUP. . . . . . . . . . . . . 203
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Connection of SUP 1011/1021 power supplies. . . . . . . . . . . . . . . . . . . . . . . . .
Connection of SUP 1051 power supplies . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Connection of SUP 1101 power supplies . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Connection of SUP A02 power supply modules . . . . . . . . . . . . . . . . . . . . . . . .
Connecting SUP A05 supply modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
General precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Chapter 16
189
190
191
193
193
196
219
220
221
225
227
228
Safety Modules PAY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 231
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
General description of safety modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Wiring precautions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cable dimensions and lengths . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
231
232
233
234
9
Chapter 18
Counter Modules CTY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 237
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 237
Process for connecting encoder count sensors . . . . . . . . . . . . . . . . . . . . . . . . . 238
General rules for implementation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 239
Connecting the encoder supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 241
Wiring precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 242
Chapter 19
Axis Control Modules CAY . . . . . . . . . . . . . . . . . . . . . . . . . . . 245
General precautions for wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 245
Chapter 20
Stepper Motor Control Modules CFY . . . . . . . . . . . . . . . . . . . 247
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 247
General precautions for wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 248
Wiring precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 248
Chapter 21
Electronic Cam Module CCY 1128 . . . . . . . . . . . . . . . . . . . . . 251
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 251
Installation precautions for the CCY 1128 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 252
General wiring instructions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 253
Selecting and protecting auxiliary power supplies . . . . . . . . . . . . . . . . . . . . . . . 254
Choice of encoders for the CCY 1128 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 255
Connecting the encoder supply to the CCY 1128 . . . . . . . . . . . . . . . . . . . . . . . 257
Wiring rules and precautions specific to the TELEFAST . . . . . . . . . . . . . . . . . . 259
Chapter 22
Analog Modules AEY/ASY . . . . . . . . . . . . . . . . . . . . . . . . . . . 263
Cabling precautions on analog modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 263
Chapter 23
Weighing Module ISPY100/101 . . . . . . . . . . . . . . . . . . . . . . . . 265
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 265
Recommendations on how to install a measurement system . . . . . . . . . . . . . . 266
Cabling precautions on the weighing module . . . . . . . . . . . . . . . . . . . . . . . . . . 268
Connection of the weighing module discrete outputs . . . . . . . . . . . . . . . . . . . . 269
10
Part VII Networks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 271
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 271
Chapter 24
Profibus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 273
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Grounding and Shielding for Systems with Equipotential Bonding . . . . . . . . . .
Grounding and Shielding for Systems without Equipotential Bonding . . . . . . .
Surge Protection for Bus Leads (lightning protection). . . . . . . . . . . . . . . . . . . .
Static Discharge in Long PROFIBUS DP Cables . . . . . . . . . . . . . . . . . . . . . . .
Capacitive By-Pass Terminal GND 001 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Chapter 25
Interbus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 285
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Momentum Communication Adapter Ground Screw Installation. . . . . . . . . . . .
Central Shielding Measures for the INTERBUS . . . . . . . . . . . . . . . . . . . . . . . .
Overvoltage Protection for Remote Bus Lines (Lightning protection) . . . . . . . .
Chapter 26
26.1
26.2
26.3
26.4
273
274
275
276
278
281
282
285
286
288
289
Ethernet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 293
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Basic rules. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Rules and precautions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Presentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Earth and ground connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Differential Mode and Common Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Wiring the ground connections and the neutral. . . . . . . . . . . . . . . . . . . . . . . . .
Choice of Transparent Factory electric wiring . . . . . . . . . . . . . . . . . . . . . . . . . .
Sensitivity of the different families of cables . . . . . . . . . . . . . . . . . . . . . . . . . . .
Wiring regulations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Rules to follow by the fitter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
First wiring rule . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Second wiring rule. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Third wiring rule. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Using the cable runs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Basics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Basics on how to use cable runs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Verification modes of the length of a homogeneous cable . . . . . . . . . . . . . . . .
Verification mode of a the length of a heterogeneous cable . . . . . . . . . . . . . . .
Other protective effects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Inter building links . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Wiring electrical connections. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Protection against intrusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
293
295
295
296
297
299
300
301
302
303
303
304
305
305
306
306
307
312
314
315
317
317
318
319
11
26.5
Using optical fiber . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 320
Choosing and Fitting Optical Fiber. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 320
Choosing the optical connection type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 321
Fitting the optical patches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 321
Chapter 27
Modbus Plus Network . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 323
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 323
Modbus Plus Termination and Grounding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 324
Fiber Repeaters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 327
Chapter 28
RIO Network . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 329
Grounding of RIO Networks. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 329
Index
12
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 333
About the Book
At a Glance
Document Scope
This manual is intended for users of Schneider Electric PLC systems during
configuration and installation and provides information regarding grounding and
measures for electromagnetic compatibility (EMC).
This manual serves the following purposes:
l Provides an overview of general problems regarding grounding and EMC
l Eases the selection of grounding and EMC measures in the entire system
(machine or system)
l Provides guidelines for configuration and installation of Schneider Electric
components regarding grounding and EMC
Section 1 contains information concerning regulations in the European Union (EU)
and in North America. This section also contains references to relevant international
standards.
Section 2 contains basic information concerning grounding and electromagnetic
disturbances. You will also find information concerning standard EMC measures
listed according to the type of measure.
Section 3 contains guidelines for EMC and grounding measures in an automated
system listed according to system area.
Sections 4-6 contains special configuration and installation information for the
following three Schneider PLC families:
l Quantum
l Premium
l Momentum
Section 7 contains special configuration and installation information for the following
network components:
l Modbus Plus
l Remote I/O
l PROFIBUS
l INTERBUS
l Ethernet
13
About the Book
Validity Note
The data and illustrations found in this document are not binding. We reserve the
right to modify our products in line with our policy of continuous product
development. The information in this document is subject to change without notice
and should not be construed as a commitment by Schneider Electric.
Product Related
Warnings
Schneider Electric assumes no responsibility for any errors that may appear in this
document. If you have any suggestions for improvements or amendments or have
found errors in this publication, please notify us.
No part of this document may be reproduced in any form or by any means, electronic
or mechanical, including photocopying, without express written permission of
Schneider Electric.
All pertinent state, regional, and local safety regulations must be observed when
installing and using this product. For reasons of safety and to ensure compliance
with documented system data, only the manufacturer should perform repairs to
components.
When controllers are used for applications with technical safety requirements,
please follow the relevant instructions.
Failure to use Schneider Electric software or approved software with our hardware
products may result in injury, harm, or improper operating results.
Failure to observe this product related warning can result in injury or equipment
damage.
User Comments
We welcome your comments about this document. You can reach us by e-mail at
[email protected]
14
Regulations and Standards
I
Overview
Introduction
This section contains information concerning regulations for EMC and grounding of
systems and machines where PLC systems are used.
What's in this
Part?
This part contains the following chapters:
Chapter
Chapter Name
Page
1
Using Regulations and Standards in the EU
17
2
International Standards
25
15
Regulations and Standards
16
Using Regulations and Standards
in the EU
1
Overview
Introduction
This chapter provides information concerning the use of regulations and standards
in the EU for systems and machines where PLC systems are used.
What's in this
Chapter?
This chapter contains the following topics:
Topic
Page
Harmonized Regulations and Standards in the EU
18
EMC Directives in the EU
21
Machine Directives in the EU
22
Low Voltage Directive
23
How to find EU guidelines and harmonized standards
24
17
Regulations and Standards in the EU
Harmonized Regulations and Standards in the EU
Harmonizing in
the EU
Harmonizing in the EU means adjusting the regulations for the individual EU
countries so that they match. For technical products, the requirements of the
products are standardized to prevent problems with trade. To harmonize the
technical requirements, EU guidelines are created to adjust the regulations so that
they match. These guidelines define basic requirements that products must meet if
they are going to be traded within the EU.
EU Guidelines
The EU guidelines are not regulations because regulations cannot be made at EU
level. But this is only a formality because the EU country is required to add the
contents of the EU guidelines to the national regulations. Therefore the
requirements defined in the EU guidelines – sooner or later – will be regulations
throughout the EU.
Examples of EU guidelines are: Machine guidelines, low voltage guidelines, EMC
guidelines, guidelines for toys, etc.
Local
regulations must
be observed!
Relevant
Guidelines for
PLC Users
18
Note: Inform yourself about local regulations and valid standards in addition to the
information provided in this manual. This manual only provides an overview.
The following guidelines are valid for EMC and the safety of electrical equipment
l Low voltage directive
Guideline 73/23/EEC from the directive of February 19th 1973 to adjust the
regulations of the EU countries concerning electrical equipment for use within
certain voltage limits
l Machine directives
Guideline 98/37/EC from the European Parliament and the directive on June
22nd 1998 to adjust the regulations and administrative directives of the EU
countries concerning machines
l EMC guidelines
Guideline 89/336/EEC from the directive on May 3rd 1989 to adjust the
regulations of the EU countries concerning electromagnetic compatibility
Regulations and Standards in the EU
Conformity
Statement and
CE Mark
The manufacturer, or whoever trades the product in the EU, must confirm that the
requirements of the respective guideline are met in a conformity statement. A CE
mark is also required for the products.
Note: The conformity is normally tested and confirmed by the manufacturer. The
CE mark is applied to the product by the manufacturer. For certain products with a
high potential for danger, the tests must be carried out by an external test lab
(e.g. for presses or woodworking systems).
Harmonized
Standards
Harmonized European standards are standards created by the European standardization organizations CEN and CENELEC and are recognized by the EU as being
harmonized standards. These standards define how the conformity to the
requirements of the EU guidelines can be achieved. Each guideline has a group of
harmonized standards.
Role of
harmonized
standards
If these standards are used, it can be assumed that conformity is guaranteed.
However, the standards do not have to be met according to law. If the requirements
of the guidelines or the corresponding national regulations are met in other ways,
this is also allowed. Using the standards has the advantage that it is easier create a
conformity statement and to confirm conformity in a court of law.
Note: However, using the standards is not enough. The standards are only the
minimum requirements. They only represent the level of technology compared to
the far reaching state of science and technology
19
Regulations and Standards in the EU
Types of
Standards
There are three types of European standard documents:
l European standard (EN...)
A European standard is the basic goal. An EN is a European technical regulation
created by CEN or CENELEC in cooperation and with the consent of the parties
concerned from the EU countries. European standards must be added to the
national standards without being changed. National standards which do not
match are to be withdrawn.
l Harmonizing document (HD...)
Harmonizing documents can be created in place of European standards if
integration identical national standards is unnecessary, or if the only way to
achieve agreement is by permitting national differences.
l European preliminary standard (ENV...)
The European preliminary standard (ENV) was created by CEN and CENELEC
to allow definitions to be made quickly which can be used immediately, especially
in areas with a high degree of innovation (e.g. IT).
The standards are classified in the following types according to the area of
application:
l Type A (general standards)
They contain technical regulations which are not product specific.
l Type B (group standards)
l Type C (product standards)
They contain technical regulations for certain products or product families.
Product standards may only complement - and not override - general standards.
Product
Standards
Product standards are valid for certain product groups. A product standard also
contains references to the general standards which are valid to the product.
Grouping requirements of various types in a document for a certain product group
reduces the overhead for the manufacturer.
Note: Requirements from product standards take precedence over requirements
from general standards.
Example: The product standard for programmable controllers and peripheral
devices is EN 61131.
20
Regulations and Standards in the EU
EMC Directives in the EU
EMC guidelines
The EMC directive for the EU passed in 1989 was used to achieve a harmonization
of the regulations for electromagnetic compatibility for technical products in EU
countries. The EMC directive was adopted in each EU country as a national EMC
regulation.
Requirements
The EMC directive requires that the devices function properly in the electromagnetic
environment without causing electromagnetic disturbances which would could
disturb the functions of other devices in this environment.
Harmonized
Standards
The requirements for protection are met if the devices follow the corresponding
harmonized European standards.
Validity
The EMC regulation is valid for devices which can cause electromagnetic
disturbances or which can be influenced by such disturbances.
This includes all electrical and electronic devices and systems with electrical or
electronic components.
It defines the conditions of such devices for
l sales,
l distribution and
l operation.
What are the
corresponding
European
standards?
Harmonized standards are standards that use the information published by the
European community as the source. The term "corresponding" means that the
standards provide information concerning the EMC requirements in general or
specially for the product type being used.
21
Regulations and Standards in the EU
Machine Directives in the EU
Machine
directives
The machine directive for the EU passed in 1989 and updated in 1998 was used to
achieve harmonizing of the regulations for safety of machines in EU countries. The
machine directive has been implemented since the 1st of June 1995 in the national
laws of every EU country and EU pre-accession country.
Requirements
The machine directive defines basic security and safety requirements for machines
and safety equipment which are required for use. These basic security and safety
requirements are supplemented by a group of detailed requirements for certain
machine types.
Validity
The machine directive is valid for machines and safety equipment.
The term machine is a general term and includes a wide range of machines and
systems.
l A unit consisting of a group of components or equipment, mostly with at least one
moving part, as well as operating machines, control loops, etc., which is used for
a certain purpose, such as processing, handling, moving and preparing a material
l A unit consisting of machines which work together in such a manner that they are
considered to function as a whole
l Exchangeable equipment used to change the function of machine which can be
obtained and added to a machine or a group of machines or a by service
personnel, as long as this equipment is not a replacement part or tool
Safety equipment, which is not exchangeable equipment, a component which the
manufacturer (or authorized personnel) places on the market with the intent of
guaranteeing safety and the failure of this component can danger the security or
safety of persons in the work area.
Exceptions
A group of products are excluded from this: People moving equipment, boilers,
atomic systems, weapons, etc.
22
Regulations and Standards in the EU
Low Voltage Directive
Full title
The full title of the low voltage directive is:
EU Directive 73/23/EEC concerning the safety of electrical equipment
Goal of the low
voltage directive
The goal of the low voltage directive (1973) is to harmonize technical safety
requirements for low voltage electrical equipment in the EU, in order to do away with
business restraints.
Validity
The low voltage directive is valid for electrical equipment that uses a rated voltage
of 50 ... 1000 V AC or 75 ... 1500 V DC.
Exceptions are:
l Electrical equipment for use in an explosive atmosphere
l Electro-radiological and electro-medical equipment
l Electrical parts of elevators for people and loads
l Electricity counter
23
Regulations and Standards in the EU
How to find EU guidelines and harmonized standards
Why only
Internet
sources?
Many manuals, standard catalogs and other printed materials are available in all
countries. However, they have the disadvantage of the fact that you never know if
they are out of date. The Internet has developed to the point that it is the best
research media for looking up information. That is why only Internet sites are listed
here.
Finding EU
directives
EU directives can be found in original text on the Internet on the European
Commission site. The site is available in all official European languages.
Step
Finding
harmonized
standards
Go to the EU Commission site http://europa.eu.int/eur-lex
2
Go to the following path on the site: Legislation in force → Industrial policy
and internal market.
3
Select Electrical material.
Result: You get a list of EU directives for electrical material as well as a direct
link to the full-text version of the directive.
The current list of European harmonized standards for each EU directive can be
found on the CENELEC site, the European standards organization for electrotechnical products:
Step
24
Procedure
1
Procedure
1
Go to the CENELEC site http://www.cenelec.org.
2
On the site, select Search → Standardization activities.
Result: A form appears with fields where you can enter your search criteria.
3
Select a topic from the list of Keywords, for example, EMC.
4
Select an EU directive from the list of Directive(s), for example 73/23/EEC.
5
Confirm your definitions with OK.
Result: You now receive a list of standards according to your search criterion.
International Standards
2
Overview
Introduction
This chapter provides information concerning international technical standards for
systems and machines in which PLC systems are used.
It explains the purpose for the standards and their role in relation to the regulations.
You will also find concrete references to relevant standards.
What's in this
Chapter?
This chapter contains the following topics:
Topic
Page
Role of the Standards
26
International Standards
27
Relevant Standards for PLC System Users
28
25
Standards
Role of the Standards
Importance of
the standards
Standards and
the law
What is
standardization?
26
The components of a PLC system are produced and tested as well as certified or
authorized according to the respective regulations and standards for the country
where they are being used.
Not only the manufacturer, but also the user of PLC systems must be aware of the
regulations and standards. The automated system in which the components of the
PLC system are installed is also subject to regulations. To meet the regulations, the
use of standards is helpful and essential as they reflect the current state of
technology.
Note: Standards can often provide security concerning product liability, but they
are not legal standards. Standardization organizations are not liable for the
suitability of the standards. This is tested by the responsible designer through
hazard analysis according to machine directives.
Standardization guarantees uniformity of materials and immaterial things for public
use and is carried out according to a plan by interested parties in the community. In
addition to company standards, national and international standards are also
created.
Standardization serves the following purposes:
l Promotes rationalization and quality assurance for trade, technology and
management
l Improves safety of personnel and material
l Improves quality in all areas of life
Standards
International Standards
International
standards
In many areas, especially electro technical engineering, there are standards which
are valid all over the world. The result of these worldwide efforts are 10,000
international standards which are used directly or can be added to the individual
national standards. These international standards are defined by international
standardization organizations.
ISO
90 countries work together through their national standardization institute in the
International Standards Organization (ISO). A well-known example of ISO's work
are the international standards for quality assurance systems ISO 9000 to 9004.
IEC
The International Electro technical Commission (IEC) is responsible for electro
technical standards. In this area, there is nearly 100% agreement with the European
harmonized standards, which is also evident in the fact that the numbering also
matches.
CISPR
CISPR is the International Special Committee on Radio Interference. The goal of
CISPR publications and recommendations is to protect radio transmission. CISPR
publications mainly contain definitions for test procedures and limit values for radio
disturbances for electrical and electronic products.
27
Standards
Relevant Standards for PLC System Users
Introduction
Product
Standards
The following standards are a selection of the most important European and
international standards which are relevant for PLC system users.
Note: Standards can often provide security concerning product liability, but they
are not legal standards. Standardization organizations are not liable for the
suitability of the standards. Only the regulations in each individual country are
binding.
The following European and international standards define safety and EMC
requirements for PLC system users. The selection has been purposefully kept small
and mainly contains product standards. Within each individual standard, you will find
a list of other standards which refer to certain products and may be valid for your
application:
28
EN-No.
Corresponding IEC No.
Title
EN 61131-4
IEC 61131 -4
Programmable logic controllers –
part 4: Guidelines for users
EN 50178
IEC 62103
Electronic equipment for use in power
installations
EN 60439 - 1
IEC 60439 -1
Low voltage switching device
combinations
EN 60950
IEC 950
Safety of IT equipment
Standards
General
standards
The following European and international standards define safety and EMC
requirements which do not refer to certain products and may be valid for your
application:
EN-No.
Corresponding IEC No.
Title
HD 384.4.41
IEC 60364-4-41
Electrical Installations of Buildings Part 4: Safety measures
Chapter 41: Protection against
electrical shock
EN 61140
IEC 61140
Protection against electric shock.
Common requirements for systems
and equipment
EN 60204 -1
IEC 60204 -1
Safety of machines - electrical
equipment of machines
EN 50310
Use of measures for equipotential
bonding and grounding in buildings
with IT equipment
EN 50174 -1
IT - installation of communication
cabling – part 1: Specifications and
quality assurance
DIN EN 50174-2
IT - installation of communication
cabling – part 2: Installation planning
and practices in buildings
29
Standards
30
Grounding and Electromagnetic
Compatibility (EMC) - Basics
II
Overview
Introduction
This section contains basic knowledge concerning the subject area of this manual:
Grounding and Electromagnetic Compatibility.
This section consists of terms, definitions and explanations of physical combinations
that will be required in understanding some of the measures that will be introduced
in subsequent sections.
Planning regulations can be found in Earth and EMC Measures in Automation
Systems - System Guidelines, p. 89 and Product Specific Grounding and EMC
Measures - Guidelines.
What's in this
Part?
This part contains the following chapters:
Chapter
Chapter Name
Page
3
Grounding - Basics
33
4
Electromagnetic Disturbance and EMC
45
5
Basic EMC Measures
79
31
Basics
32
Grounding - Basics
3
Overview
Introduction
This chapter explains the terminology connected with grounding that can be helpful
and is sometimes required for understanding grounding procedures for a system or
a machine.
What's in this
Chapter?
This chapter contains the following topics:
Topic
Definitions: Earth, ground, reference conductor system
Page
34
Ground Connections in TT, TN and IT Alternating Current Systems
36
Personal Danger through Electrical Current
38
Electric Shock: Causes and preventative measures
39
Classes of Protection for Electrical Equipment
41
Protective Earth
42
33
Grounding
Definitions: Earth, ground, reference conductor system
Earth and ground
In almost all devices or systems, you should differentiate between the earth (earth
conductor) and the common ground (reference conductor system/neutral
connection). Earth and common ground are normally connected to each other in a
certain place. However, there is a difference:
Note: Earth only conducts fault currents and common ground conducts operational
current and is often used as the common conductor for several signal circuits.
Earth
Earth is the conductive potential of our earth. The electrical potential of the earth is
considered to be zero. Inside a system, earth is understood as being the protective
conductor used for protecting people, animals and goods.
Terms used as synonyms for Earth: Equipment grounding conductor, earth,
protective earth, chassis or frame ground, station ground
Ground
This is the common base for all connected conductive inactive components of
electrical equipment and is not a route for operational voltage even when a fault
occurs. The common ground is the equipotential offset for a system and is used as
a common ground plane for electronic circuits.
The common earth plane is normally connected with the earth (grounded) in a
stationary system. Common ground does not necessarily have to be connected with
earth ground however (in airplanes for example).
Common ground is found performing the following functions:
l Equipotential plane for the reference conductor system of the electronics
l Equipotential bonding and over voltage protection for all installations of metal,
electrical systems, lightning protection system and grounding system
l Protective function for people: Common potential is kept low in relation to earth
potential so that a human would not be harmed by coming into contact with parts
of the system
l Rerouting over-voltages (caused by faults in the system, lightning)
Terms used as synonyms for Common Ground: Equipotential bonding, neutral,
switching ground, signal reference, signal ground, measurement ground, 0 V,
reference conductor ground
34
Grounding
Common ground
examples
Reference
conductor,
reference
conductor
systems
Common ground examples:
Metallic structural elements of a building (framework, piping, etc.)
Motor housing
Metal cabinets, unpainted floor plates on housings
Metallic cable ducts
Transformer housing, machine bed plate
Yellow-green wire (PE-PEN) for grounding
l
l
l
l
l
l
The reference conductor for an electronic operation is the reference potential. It is
connected with the common ground.
The reference conductor system makes a galvanized connection of all 0 Volt wires
that are required in the current loop of the electrical equipment. No voltage
differences may exist between the various points of the electronic reference plane
otherwise unintended signal voltages can occur.
Normally, several circuits are operated on a common reference conductor system
for the exchange of necessary signals.
Terms used as synonyms for Reference Conductor systems: Neutral (system)
35
Grounding
Ground Connections in TT, TN and IT Alternating Current Systems
Distribution
systems
Ground connections in our alternating current systems (single-phase, three-phase,
rotary current systems), these systems can be put into three separate categories
(IEC 60364):
System name
Type of ground connection to the Type of ground connection to
energy source (first character)
the electric operation (second
character)
TN system
A certain point on the neutral
conductor, normally close to the
feeding current source, is grounded
directly.
Variations
TN-S system
TN-C system
TN-C-S system
The body of the electrical
equipment is connected with the
ground point using a ground
conductor.
Depending on the application of
the N conductor, TN systems are
split into three different types:
l S: Separated neutral and
equipment grounding
conductors
l C: Combined neutral and
equipment grounding
conductors (PEN)
l C-S: System with TN-C
section(s) and TN-S section(s)
TT system
A certain point on the neutral
conductor, normally close to the
feeding current source, is
connected with a ground
connection.
The body of the electrical
equipment is connected with other
grounding elements, independent
of the neutral ground.
IT system
No point in the system is grounded
directly.
The body of the electrical
equipment is grounded.
Note: Security stipulations for these various systems (cut-off conditions for
example) are found in IEC 60364-4-41.
36
Grounding
Character
definitions
First and second
letter
assignment
The letters have the following meanings:
Letter
Origin
Meaning
T
French: terre (Earth)
Direct connection of a point to earth
I
isolated
Either all active parts are separated from earth, or
one point is connected through an impedance with
earth
N
neutral
Body is connected directly to the ground point of
the system
(In alternating current networks, the grounded
point is normally the zero conductor or if none
exists then the external conductor.)
S
separate
A conductor is provided for a protective function
and is separated from the neutral or the external
conductor.
C
English: combined
Neutral and protective function combined in one
conductor (PEN conductor)
The identifying letters for the current distribution system are assigned as follows:
l First letter: Indicates the ground connection to the energy source (Transformer for
example)
l Second letter: Indicates the ground connection to the electrical equipment
37
Grounding
Personal Danger through Electrical Current
Dangerous Body
Currents
(Electrical
Shock)
An electrical shock is the result of current flowing through the human body. Currents
of 1 mA can cause reactions in a person of good health which can in turn cause
shock to a dangerous degree. Higher levels of current can result in more damage.
In dry conditions, voltages to around 42.4 V peak value or 60 V constant voltage are
not normally considered dangerous.
Components that must be touched or gripped should be connected with protective
ground or should be sufficiently insulated.
Energy hazards
Short circuits between neighboring poles of power supply devices of higher current
levels or circuits with high capacity can cause arcing or sparking of hot metal
particles and result in burns. Even low voltage circuits can be dangerous in this way.
Protection is achieved by separation or safety devices.
Burns
A burn can be caused by temperatures that are the result of overloads, component
failures, insulation damage or loose connections or those with high transition
resistance.
The protective measures concern prevention of burns, the selection of materials
regarding inflammability, measures for limiting the spreading of burns, etc.
Miscellaneous
indirect hazards
Other indirect dangers
l Dangers of heat: Danger of injury caused by touching hot components.
l Dangers of radiation: Hazardous radiation, e.g., noise, high frequency radiation,
infrared radiation, visible and coherent light of high intensity, ultraviolet and
ionizing radiation, etc.
l Chemical hazards: Danger of contact with dangerous chemical materials.
38
Grounding
Electric Shock: Causes and preventative measures
Dangerous
voltages
Causes
The following voltages can be dangerous:
l A.C. voltage with a peak value of 42.4 V and higher
l D.C. voltage of 60 V and higher.
If a person touches a component that is under dangerous voltage, it can cause
electric shock. This contact is divided into two categories:
Type of contact
Definition
Direct contact
Contact with components that are supplied with a voltage
in undisturbed operation
Indirect contact
Contact with components that are supplied with a voltage
caused by a fault
Preventative
measures
against direct
contact
If components carry dangerous voltage, people must be prevented from coming into
direct contact and therefore risking injury.
The following measures considered:
l Secure separation between circuits
l Housing or cover
l Insulating active components
l Energy restrictions (capacitor loads, protective impedance)
l Voltage restriction
l Additional fault current protective circuits
Preventative
measures for
indirect contact
A fault could also occur, in which case preventing people from getting an electric
shock (by indirect contact) is also necessary.
The following measures can be considered:
l Doubled/reinforced insulation
l Basic insulation and protective grounding
l Additional fault current protective circuits
39
Grounding
Respective
standards
40
Regulations for protective measures against electric shock are covered in the
following standards:
l Safety regulation standard:
IEC 61140: Protection against electric shock. Common requirements for systems
and electrical equipment (safety standards)
l Safety group standards:
IEC 60364-4-41: Electrical Installations of Buildings - Part 4: Protection for
Safety, Chapter 41: Protection against electrical shock
l For systems:
IEC 62103 and EN 50178: Electronic equipment for use in power installations
l For machines:
IEC 60204: Safety of machines - electrical equipment of machines
Grounding
Classes of Protection for Electrical Equipment
Classes of
Protection
Electrical equipment is divided in protection classes 0, I, II and III. These classes of
protection are defined by the method in which the protection against electric shock
is achieved (IEC 61140).
Programmable Logic Controllers and their peripherals must correspond with
protective classes I, II or III (according to IEC 61131-2).
Protective
Class 0
Electrical equipment for which the protection against dangerous body currents only
contacts the basic insulation belongs to protective class 0. This means that no
medium for connecting conductive components to the protective conductor (ground
conductor) is provided in the permanent wiring of the system. If the basic insulation
fails then the surrounding environment is trusted.
Protective
Class I
Electrical equipment for which the protection against dangerous body currents does
not only contact the basic insulation belongs to protective class I. An additional
contact for connecting conductive components to the protective conductor (ground
conductor) is provided in the permanent wiring of the system. Components that can
be touched are voltage-free if the basic insulation fails in this case.
Protective
Class II
Electrical equipment for which the protection against dangerous body currents does
not only contact the basic insulation belongs to protective class II. An additional
safety feature such as doubled insulation or reinforced insulation is provided but no
protective ground.
Protective
Class III
Electrical equipment for which the protection against dangerous body currents is
achieved by safety extra-low voltage (SELV) supply belongs to protective class II. In
this type of electrical equipment, no voltage that is higher than the SELV is
produced.
SELV
SELV (Safety extra-low voltage): is defined as a voltage that, measured between
conductors or between a conductor and ground, does not exceed 42.4 V peak or
constant voltage. The circuits in which these are used must be separated from the
power supply by a safety transformer or a similar device.
41
Grounding
Protective Earth
Alternatives:
Insulation or
protective earth
All components of a system or machine that can be applied with a dangerous
voltage if a fault occurs must be taken into account. To guarantee safety, these
components can either be double insulated or reinforced or they can be equipped
with a protective earth.
Protective earth:
Definition
Protective earth is the earth that is mainly for guaranteeing the safety of human
beings.
The protective earth is a preventative measure for avoiding an electric shock caused
by indirect contact, i.e., contact with a component that has been applied with a
dangerous voltage as a result of a fault - failure in the basic insulation for example.
Note: The protective earth is clearly separate from the functional earth. The
functional earth is not for safety, it is a functional component; it is used as a
reference voltage or for rerouting interference current for example.
Grounding
arrangements
and protective
conductors
The precision of the connection to the ground potential depends on the electrical
equipment, the components and the type of current distribution (TT, TN, IT system).
Some important standard principles for protective earth are:
l The cross section of the protective ground wire must correspond with the
maximum expected leakage current.
l Electrical connections must correspond with the loads that are possible in
practical operation.
l The protective ground must also be guaranteed operational during service and
maintenance work.
l The protective earth overrides the functional earth. It may not e.g. be used to
disabled to improve the electromagnetic compatibility.
Note: IEC 60364-5-54 contains requirements for the earth system and protective
grounding conductors.
42
Grounding
Protective earth
for PLCs
Programmable Logic Controllers and their peripherals that belong to protective class
I have a protective earth connection.
There are two ways of connecting to the earth system:
l The protective conductor is found in the power supply wire directly from the
electric supply (mains).
l The device has a protective conductor connection for connecting to an external
protective conductor.
All components of the device that a person can come into contact with (e.g. frame,
housing, mounts) are connected electrically and are connected with the protective
conductor connection so that no dangerous voltage can enter. The protective
conductor connection must remain intact when working on the device as long as the
supply is connected.
Requirements for the construction of PLCs and their peripherals can be found in IEC
61131-2 Programmable Controllers, Part 2: Equipment requirements and
tests.
43
Grounding
44
Electromagnetic Disturbance and
EMC
4
Overview
Introduction
This chapter contains the electronics basics on electromagnetic disturbance. This is
based on the following questions:
l What can electromagnetic disturbances in industrial applications actually result
in?
l What are the sources of disturbance?
l How can disturbance signals interfere with useful signals?
l What types of coupling mechanisms are there and what measures should be
used to avoid problems?
This knowledge is necessary in understanding possible disturbance phenomena
and the preventative measures that you can take in the planning and installation of
the electrical equipment in an industrial application.
What's in this
Chapter?
This chapter contains the following sections:
Section
Topic
Page
4.1
Results, Causes and Types of Disturbance
47
4.2
Overlapping of Interference and Useful Signals on Wires
57
4.3
Interference Coupling
63
45
EMC Basics
46
EMC Basics
4.1
Results, Causes and Types of Disturbance
Overview
Introduction
Electromagnetic disturbance in industrial applications can affect operation to various
degrees: From acceptable operational influences right up to damaged system
components. The causes of these disturbances lie either within the system or
outside of it and can be classified according to various criteria. The disturbances
themselves can vary and are also classified according to different criteria.
This section is concerned with the results, causes and types of disturbance. It can
mainly be used for understanding the terminology and for classification and is
therefore required for a complete understanding of the other sections of the
document.
What's in this
Section?
This section contains the following topics:
Topic
Page
Results of Disturbance to an Industrial Application
48
Principles of Interference Influence - Influence Model
49
Sources of Interference
50
Interference Variables and Interference Signals
53
Effective Parameters
56
47
EMC Basics
Results of Disturbance to an Industrial Application
Degree of effect
The effects of undesired voltage and current in industrial applications range from
acceptable functional degradation, to unacceptable functionality failures right up to
total function failures of individual components or a complete application
These effects are categorized according to degrees:
Degree of effect
Other examples
Description
Example
Function degradation A non-significant influence in
the functionality that is
accepted as being
permissible
Minor measurement imprecision is
caused by disturbances that occur on
a signal wire. These lie within the
defined tolerance.
Function fault
The function is influenced to
an impermissible degree
which ends with a dying out
of the amount of disturbance.
An incremental encoder for path
measurement is connected with a
PLC counter module. A short circuit
in a motor supply wire running in
parallel is causing a inductive
coupling disturbance and is
interfering with the useful signals on
the wires for the incremental
encoder, which is in turn being
interpreted as counter pulses by the
following circuit. This causes certain
machine functions to be executed at
the wrong times.
Function failure
An impermissible influence
on the function that can only
be resolved by technical
measures (e.g. repair,
exchange)
During a service call, an electrostatically charged technician comes
into contact with a module. An
electrostatic discharge occurs which
damages or destroys components.
More examples for the effects of disturbance in a system:
l Individual impulse, i.e. pulse formed over-voltage caused e.g. by switching an
inductive consumer such as a motor or valve. These interfere with the
functionality of digital systems by setting or clearing registers if the interference
threshold of the device is exceeded.
l A building only has one external lightning rod and no protection against lightning
inside. When lightning strikes, some of the discharge flows into the building and
damages electronic circuits.
48
EMC Basics
Principles of Interference Influence - Influence Model
Influence model
The electromagnetic influence of applications happens when a disturbance variable
is transferred from an interference source through couplings to susceptible
equipment.
The description of the electromagnetic influence follows an influence model
consisting of interference source, coupling and susceptible equipment:
Disturbance
Source of Interference
Disturbance
Coupling
Susceptible equipment
Source of
interference
Interference sources are the origin of disturbance variables. Potential sources of
interference are all applications in which electromagnetic energy is transferred.
Interference sources can lie within (system internal) or outside of (system external)
the system in question.
Coupling
The coupling of disturbance variables to susceptible equipment can happen in
various ways:
l Galvanic: Coupling through a common circuit
l Capacitive: Coupling through the electric field
l Inductive: Coupling through the magnetic field
l Wave or radiation influence: Coupling through the electromagnetic field
Susceptible
equipment
Susceptible equipment is any device or component for which the functionality is
disturbed by the disturbance variable.
Disturbance
(disturbance
variable)
A disturbance variable (interference) can be electrical voltage, currents, electrical
and magnetic fields. They are caused by electromagnetic proceedings, have a
broad amplitude and frequency range over varying amounts of time and result in a
reduction of functionality in susceptible equipment of varying intensity.
49
EMC Basics
Sources of Interference
Classification of
sources of
interference
The following classification for sources of interference can be helpful:
Natural and technical sources
Sources having narrow-band and broad-band frequency spectrums
Sources for conductor and radiated disturbance variables
Power supply as source of interference
Regular and unintended (leakage) sources
Continuous and intermittent sources
l
l
l
l
l
l
Natural and
technical
sources of
interference
We differentiate between natural and technical sources of interference:
Narrow-band
interference
source
Narrow-band sources of interference are sources having signals with discrete
frequencies such as:
l Radio and amateur radio transmitters
l Transmitter receiver devices
l Radar stations
l Industrial HF generators
l Microwave devices
l Energy currents
l Welding machines
l Sound or FX receivers
l Ultrasonic devices
l Power converter circuits
These can generate substantial electromagnetic fields, primarily in the immediate
vicinity.
50
Natural sources of interference
l
l
l
Lightning
Atmospheric and cosmic noise
Electrostatic discharge
Technical sources of interference
For example:
l Thyristor controllers that interfere by
steep current slopes
l Switching high powered applications on
and off
l HF Producer
l Transmitter
l Oven
l Local oscillators
EMC Basics
Broad-band
interference
sources
Broad-band sources of interference of conducted and radiated disturbance
variables are feared disruptors in electronic automation systems, since they have
very high frequencies in addition to a wide frequency spectrum.
The following belong to the broad-band sources of interference:
l Motors
l Discharge lamps
l Circuit breakers (power switches)
l Isolating switches in energy supplies
l Noise
l Controller circuits with semi-conductors
l Switching devices (relay, contact)
l Electrostatic discharge
l Atmospheric discharge
l Corona
l Nuclear discharge
Sources of
conducted
interference,
power supply
(mains)
Conducted influences run through metal conductors (wires or conductive
structures), transformers, coils and capacitors. Since conductors effectively work as
antennas as well, the interference can also be converted into a radiated disturbance
or vise versa.
Examples: Frequency spectrum of conducted disturbances:
Source
Predominant frequency spectrum in
MHz
Fluorescent tube
0.1 ... 3
Mercury arc lamps
0.1 ... 1
Data processing systems:
0.05 ... 20
Commutators
2 ... 4
Circuit breaker contacts
10 ... 20
Protection, Relay
0.05 ... 20
Power switch
0.5 ... 25
DC power supply (clocked)
0.1 ... 25
Corona
0.1 ... 10
Vacuum cleaner
0.1 ... 1
Many of the previously mentioned interference sources are connected to the main
supply. The respective disturbance variable is sent out onto the supply network and
passed on from there. Therefore, the power supply network can itself be the source
of continuous and intermittent interference.
51
EMC Basics
Radiated
sources
Interference
If the dimensions of the components are small compared to the wave length of the
disturbance, then the radiated influence can be monitored separately over the
electrical and magnetic fields.
With higher frequencies, the electromagnetic field must be monitored as a whole.
This means that all devices, in which higher frequencies are generated and on which
components deliberately or accidentally work as antennas, are to be considered as
potential sources of interference.
Example: Frequency spectrum of radiated disturbances:
Source
Predominant frequency spectrum in
MHz
RF surgery
0.4 ... 5
Bistable latches
0.015 ... 400
Thermostat contacts (Arc)
30 ... 1000
Motor
0.01 ... 0,4
Arcing circuits
30 ... 200
DC power supply
0.1 ... 30
Untreated device housing
0.01 ... 10
Fluorescent tube, arcing
0.1 ... 3
Semiconductor-multiplexer
0,3 ... 0 5
Cam contacts
10 ... 200
Circuits
0.1 ... 300
Regular and
unintended
(leakage)
sources
The differences between regular and unintended sources can be helpful in EMC
work when monitoring frequency ranges for devices, in taking the appropriate
measures for decreasing interference or in searching for unknown interference
sources. The emission values of regular sources must be taken into account as part
of the planning procedure.
Continuous or
intermittent
Sources
Differentiating between continuous or intermittent interference is required if for
example, a certain influence should be shut off for timed operations of interference
sources and receivers.
Example: Switching off receivers for weather
52
EMC Basics
Interference Variables and Interference Signals
Overview
The disturbance variables and the interfering signals that result from them cover a
wide frequency and amplitude range. They can occur in many curve forms and be
put into many different classifications.
When referring to time, the occurrences are classified as periodical and non-periodic
interference variables.
Periodic
interference
Periodic interference consists of sinus formed signals. External sinus formed
interference sources are radio and television transmitters and radiotelephony.
In industrial applications, periodic interference is caused by alternating and rotating
current components, power converters, fluorescent lamps, combinational circuit
components and PCs. They create continuous distortion in supply voltage, voltage
fluctuation, voltage drops and dissymmetry in rotary current supplies.
Periodical interference:
A
A
t
f
53
EMC Basics
Non-periodic
interferences transients
Non-periodic interferences are short interfering pulses (Transients).
The characteristics of these transients are the rate of change voltage dU/dt and
current di/dt fluctuations. In industrial networks, shut-off overvoltage can reach as
high as 10 kV with rise time in the nsec. to sec. range and frequencies up to 100
MHz. The voltage increase speeds of these feared bursts lie between 2 and 5 kV/
nsec with a pulse duration of 100 nsec to 1 msec.
Transient pulses are noticed especially in digital systems since they can disrupt
functionality by setting or clearing memory locations (flags and registers).
Transients and bursts are normally caused by arc charges or switching functions in
the following procedures:
l Normal switching and commutation events with high and low voltage switching
devices, mainly through mechanical contacts
l Short circuits, voltage surge, lightning discharge
Non-periodical interference:
A
A
t
54
f
EMC Basics
Non-periodic
interference to
supply voltages
Interfering voltages into the kV range can occur because of non-periodical
interference to supply and data lines.
Various forms of interference in industrial networks:
1
2
A
A
t
t
3
4
A
A
t
1
Commutation drop
2
Phase controller
3
Transient processes
4
Burst
t
55
EMC Basics
Effective Parameters
Interference
parameter
Causes of
effective
interference
Parameters for interference variables are:
l Rise time: as a measurement of the duration of the interference
l Rate of change du/dt, di/dt: as a measurement of the intensity of the interference
l Peak value: as a measurement of the energy of the interference
Note: Causes of effective interference are exclusively amplitude variations in
electrical parameters per time unit. The duration of the interference is identical to
the duration of the change in the source of interference.
Frequency
influence
The frequency spectrum of a disturbance variable is important because the inductive
resistance and the capacitive resistance on a conductor depend on the frequency.
The higher the frequency of the interference, the higher the interfering signal.
Frequent interference signals cause a voltage drop on the inductive resistance of
conductors which shows up as interference voltage. This causes a carrier flow on
the line capacity that shows up as interference current.
Frequency
spectrum of an
interference
pulse
To simplify matters, an interference pulse can be considered as a rectangular pulse
form. This can be calculated as a sum of sinus functions. To recreate this pulse more
precisely, i.e. the more slope that is defined for a pulse edge, the more frequent the
required voltages must be.
56
EMC Basics
4.2
Overlapping of Interference and Useful Signals on
Wires
Overview
Introduction
The structure of electrical circuits is important to the way that an interference signal
disrupts the useful signals and how well that the interference signal can be
separated from the useful signal.
This section explains the terms symmetric and asymmetric electrical circuits and the
common mode interference and the differential mode interference as the principal
types of overlaying of interference and useful signals in electrical circuits.
These basics are required in order to understand the EMC measures for balancing
circuits.
What's in this
Section?
This section contains the following topics:
Topic
Page
Symmetrically and Asymmetrically Operated Circuits
58
Differential Mode Interference
59
Common Mode Interference
60
Common Mode-Differential Mode-Conversion
62
57
EMC Basics
Symmetrically and Asymmetrically Operated Circuits
Symmetrical
circuits
The outgoing and return wires of the reference ground are separated in
symmetrically operated circuits. The electrical circuit is connected with the reference
ground with a third wire so that a symmetrical circuit makes up a three wire system.
The useful signal flows to the device through the outgoing wire and back down the
return.
Many interferences can be reduced with a symmetrical connection which is also
quite often the reason that they are used.
Typical symmetrical circuit:
l Connections in measurement systems between sensors and electronics
l Connections for symmetrical data connections (RS422 / V.11)
l Telephone connections between participants and the central exchange
Asymmetrical
circuits
In an asymmetrically operated circuit, the circuit is closed with the connection to the
earth reference plane. The wanted signal flows to the device through a single wire
and back down the earth reference plane.
Note: All connections run through coax cable are asymmetrical connections.
Differential mode
and common
mode
interference
58
The useful signal is fed into the circuit in differential mode, i.e., the useful current
flows in on the feed wire and out on the return wire or the earth reference plane.
Interference can also be fed in as a differential mode signal. Interference can
however also be fed in as a common mode signal. Common mode interference
means that the interfering current flows in the same direction on both branches of
the circuit and is returned on the earth reference plane. When the reference ground
wire is not connected well, the interfering current caused by the common mode
interference can be transmitted to other signal lines that are connected on the same
device.
EMC Basics
Differential Mode Interference
Differential mode
interference
A differential mode interference is caused if an interfering voltage is coupled into one
branch of a circuit only. A potential difference is then caused between the outgoing
and return wires. Causes are currents in the outward and return conductors to the
earth reference plane in opposite directions. The interfering circuit closes
exclusively with a galvanic connection.
Circuit diagrams for a symmetrically and an asymmetrically operated electrical
circuit with differential mode interference.
Differential mode interference in a
symmetrically operated electrical circuit
ZA
2
UN
Differential mode interference in an
asymmetrically operated electrical circuit
UN
UN + US
UN + US
ZA
2
US
Z
US
Character definitions
Character Meaning
Causes
UN
Wanted Voltage
US
Interference voltage
Z
Impedance (e.g. in measurement device)
Common mode interferences have many different causes and are coupled either
inductive or capacitive:
l Switching frequency and the respective harmonic waves
l Oscillations that can be caused by capacitance or inductance of components or
wiring arrangements (parasitic)
l Common mode-differential mode-conversions in unwanted asymmetries on the
circuit
59
EMC Basics
Separation of
useful and
interfering
signals
Note: Useful signals and interference signals cannot be separated from one
another in symmetrical or asymmetrical operations. Therefore, differential mode
interference should be avoided.
Common Mode Interference
Definition of
common mode
interference
Common mode interference is caused if an interfering voltage is coupled into both
branches of a circuit. This increases the potential in the outgoing and return lines.
Common mode interference current flows in the same direction as everything else
on these lines. The circuit closes with the earth reference plane or with unwanted
capacities.
Circuit diagrams for a symmetrically and an asymmetrically operated electrical
circuit with common mode interference.
Common mode interference in a
symmetrically operated electrical circuit
Common mode interference in an
asymmetrically operated electrical circuit
UN
UN
UN
ZA
US
US
Character definitions
Character Meaning
60
US
Interference voltage
UN
Wanted Voltage
Z
Impedance (e.g. in measurement device)
UN
ZA
EMC Basics
Causes
Common mode interferences have many different causes and are coupled either
inductive or capacitive:
l Inductive coupling if electromagnetic fields are found in the area between the
symmetrical wire pair and the ground
l The transmitter of a system sends a common mode signal to a neighboring wire
pair which is coupled with other pairs as direct-axis voltage components
l The switching transistor housing is either at operating voltage potential or at zero
depending on the clock pulse; these voltage jumps are coupled to the heat sink
and therefore earth reference plane with capacitance
Common modedifferential
modeconversion
Normally, interference occurs in the form of linear or common mode voltage and only
then causes an interfering differential mode signal because of insufficient symmetry.
When the impedance of the lines is uneven or if stray capacities are found, a
common mode-differential mode-conversion occurs. The asymmetrical ratios then
create a differential voltage which is then carried with the useful signal.
As soon as anything asymmetric occurs a coupling of the interference source to the
useful load occurs.
61
EMC Basics
Common Mode-Differential Mode-Conversion
Common modedifferential
modeconversion
When the impedance of the lines is uneven or if stray capacitances are found, a
common mode-differential mode-conversion occurs. The asymmetrical ratios then
create a differential voltage which is then carried with the useful signal.
Circuit diagram of common mode-differential mode-conversion with stray
impedances Z St between the circuit and reference ground as well as with different
line impedances Z L.
ZL1
IS1
USL1
USt1
UN + U’S
UN0
ZA
U
IS
ZSt1
USt2
IS2
ZL2
ZSt2
IS
US
IS
Character definitions
Character Meaning
62
UN
Useful voltage
US
Interference voltage at the source interference
US ’
The signal voltage is overridden by the interference voltage; this part is brought
about by the common mode-differential mode-conversion
Z
Impedance (e.g. in measurement device)
ZL 1,2
Different line impedance in lines 1 and 2
ZSt 1,2
Stray impedances
IS
Interference current
IS1,2
Partial current in both branches of the electrical circuit
EMC Basics
4.3
Interference Coupling
Overview
Introduction
Interference has various methods of coupling into the electrical equipment and
spreading. The different coupling methods or coupling mechanisms are described
in this section. You will also read about which parameters determine the size of the
coupled interference signals. At the end of the section you will find a table overview
indicating the measures to take for each type of coupling.
A sound knowledge of coupling mechanisms, the influential parameters and the
proper basic solutions is necessary for understanding and selecting the proper EMC
measures in an industrial application.
What's in this
Section?
This section contains the following topics:
Topic
Page
Interference Coupling Mechanisms
64
Galvanic Coupling
66
Inductive Coupling
69
Capacitive Coupling
72
Radiating Coupling
75
Wave Influence
76
Which measures for which type of coupling?
77
63
EMC Basics
Interference Coupling Mechanisms
Overview
To put the proper EMC measures to use during planning and in service, you need
to know types, effects and methods of transfer of the coupled interference. This is
the only way to effectively combat the problems.
Generally, the physical laws of energy transfer in electromagnetic fields apply for the
coupling.
Methods of
transfer
The interference can be transferred along a conductive wire (guided) or through
space (unguided/radiated). Interferences are normally found together as line guided
and radiated interference and are coupled to inputs, outputs, the power supply and
data lines.
"Size" Wave
lengths
If the wave lengths of the interference variables are greater that the characteristic
measurements of the source and receiver, the transfer mechanisms for electrical
and magnetic fields are monitored separately.
l Galvanic coupling with common impedances on the influential electrical circuits
(source and receiver)
l Inductive coupling with the common magnetic field of source and receiver (low
pass field coupling)
l Capacitive coupling with the electrical field between the source and receiver (low
pass field coupling)
"Small" Wave
lengths
If the wave lengths of the interference are the same or are less than the
characteristic measurements of the source and receiver, a coupling over the
electromagnetic field must be monitored. The following influential mechanisms play
a part:
l Wave influence with wave activity on lines
l Radiated coupling through space
64
EMC Basics
Interference coupling occurs via the following mechanisms:
Magnitude of the wave length is
equal to or smaller than the
characteristic measurements
Galvanic coupling
Wave influences
Inductive coupling
Radiation coupling
Line
connected
Wave length greater than
the characteristic measurement
Radiated
Coupling
mechanisms
Capacitive coupling
65
EMC Basics
Galvanic Coupling
Mechanism
Galvanic coupling is a line guided coupling. This phenomenon occurs if shared line
sections belong to different circuits. With every change in current in one of the
circuits a voltage change is made on the common line so that the circuits influence
each other.
Galvanic coupling typically occurs on the following circuits:
l Coupling of different circuits to the same power supply
l Coupling between operational circuits and grounding circuits (earth circuit
coupling)
l Coupling different circuits with a common reference conductor system
Example
The following circuit diagram shows two circuits with a common reference
conductor.
PLC
U2
ZL
U1
i
LL
RL
RSK
UST
Character definitions
Character Meaning
U1
Voltage in circuit 1
U2
Voltage in circuit 2
USt
Interference voltage
ZL
Impedance of the common line from circuits 1 and 2
When a circuit is wired as seen in the upper diagram then switching the contact in
circuit 1 causes a voltage drop on the common line impedance Z L. This voltage drop
overrides the proper signal in circuit 2 as interference.
66
EMC Basics
Size of the
interference
The intensity of the interference is determined by the impedance of the common
conductor and the size of the change in current.
Note: Especially highly frequent transient interference currents can cause extreme
voltage drops.
Voltage drops on a common conductor with a change in current
∆I
U St = R L × ∆I + R SK ( f ) × ∆I + L L × -----∆t
Character definitions
Character Meaning
I
Current fluctuation
USt
Interference voltage
LL
Self inductivity on the common line (frequency dependent)
RL
Actual resistance of the common conductor
RSK
Additional resistance on the common conductor caused by skin-effect
(frequency dependent)
Actual
resistance RL
The Ohmic DC resistance RL is effective for currents with frequencies into the
Kilohertz range. Utilizing a broad enough cross-section wire generally cures the
problem.
Resistance with
skin effect RSK
The resistance increase caused by the skin-effect basically rises according to the
following formula
R SK = R L × K × f
Character definitions
Line inductivity
LL
Character
Meaning
K
Geometry factor (less with larger conductive surface)
f
Interference frequency
The self inductance LL depends on the line geometry and the distance to the ground
environment and can be reduced by a factor of 10 by a conductor with a broader
surface area. With standard signal lines and wiring, it has approximately the value:
H
L L ≈ 1 µ × ---m
67
EMC Basics
Influence of line
geometry
The effects of line geometry on the frequency dependent effective resistance R are
shown in the following diagram. The diagram on the left shows the dependence for
a conductor with a round cross section and the one on the right shows the same for
a conductor with a rectangular cross section.
b
103
m
20
D=
D
102
m
o
D
R
R0
m
=2
101
D=
m
0, 2
mm
=1
a/b = 10 0
m,
10
m
a/b
20
m, / b =
D = 2 0 m m, a
m
D = = 20
D
100
102
103
104
105
f
R
106
107
108 H 109 102
103
104
105
106
107
108 H 109
f
Effective resistance
R0 D.C. resistance
Note: The effective resistance and therefore the influence of high frequency
interference currents can be reduced by using broader conductor surface area.
68
EMC Basics
Inductive Coupling
Mechanism
Inductive coupling - or sometimes known as transformer coupling - is a coupling via
the magnetic field. This occurs between lines running parallel to one another.
Current changes in a wire cause a fluctuation in the magnetic field. The resulting
magnetic field lines affect parallel running wires and induce an interference voltage
there. A current now flows which overrides the useful signal as an interference
signal.
Inductive coupling is caused in parallel running lines in cables, wire harnesses and
cable ducts.
Well known sources of interference are:
l Conductors and electrical equipment with high and fluctuating operational and
interfering currents (short circuit currents)
l Lightning discharge currents
l Capacity switching
l Welding current generators
The following circuit diagram shows the construction of inductive coupling. Current
changes in circuit 1, which are caused by switching large loads or those that are
caused by a short circuit, are producing a fluctuation in the magnetic field.
Circuit 1
MK
I
I
Φ
Φ
Circuit 2
Size of the
interference
The interference voltage caused by the inductive coupling depends on the coupling
inductivity MK between the two conductors and the current change time di/dt on the
power line:
di
U St = MK × ----dt
69
EMC Basics
Coupling
inductivity MK
Coupling inductivity M K is determined by the circuit arrangement. The coupling is at
its largest if the circuits lie tight together as with a standard transformer.
d
2
1
h
2
µH
m
MK
I 1
0
01
1
100
1
Circuit 1
2
Circuit 2
h
Distance between the outgoing and return lines of the circuit loop or between signal lines
and the ground plate.
d
Distance between the circuit loops (cable spacing)
l
Distance that the lines run in parallel
Realistic example values for the coupling inductivity:
l Tightly packed cable: h = 2 mm, d = 4 mm
MK = 80 nH/m
l Cable spacing 10 cm: h = 2 mm, d = 100 mm
MK = 1.5 nH/m
70
10
h/d
EMC Basics
Example: Cable
spacing
influence
The following calculation example for inductive coupling of two electric circuits
shows the influence that cable spacing has on the amount of induced interference
voltage: Increasing the space between cables from 4 mm (tightly packed cable) to
10 cm reduces the induced voltage in the disturbed circuit by 98 percent!
l Parallel cable length
l = 100m
l Switching current in power cable
I = 100A
l Duration of the current surge:
t = 10µs
The induced voltage in the disturbed circuit depends on
Cable spacing d
Coupling inductivity MK
Induced voltage in the
disturbed circuit USt
4 mm
(cable tightly packed)
80 nH/m
80 V
10 cm
1.5 nH/m
1.5 V
71
EMC Basics
Capacitive Coupling
Mechanism
Capacitive coupling is a coupling via the electric field. It occurs between neighboring
circuits - such as between high power current and signal lines. A fluctuating potential
difference between the two circuits allows electrical current to flow through the
insulation medium, air for example, that lies between them. The two lines that are
lying next to one another can be considered as electrodes of a capacitor which is
indicated by coupling capacity C K.
Well known sources of interference are:
l Switching off power lines
l Inductivity switching
l Lightning discharges
l Electrostatic discharge
The following circuit diagram shows the construction of capacitive coupling. Circuit
1 indicates a high power line for example and circuit 2 an analog measurement line.
When the high power line is switched off, the potential difference between the two
neighboring lines is changed. Interference current iK flows through the coupling
capacity:
iK
1
CK
2
U
Character definitions:
Character Meaning
72
1
Circuit 1: Interference source (high power cable for example)
2
Circuit 2: Susceptible equipment with impedance Z2
CK
Coupling capacity
iK
Interference current flowing through the coupling capacity
EMC Basics
Size of the
interference
The amount of interference current ISt caused by capacitive coupling depends on
coupling capacitance CK between the two conductors and the duration of the
change in voltage du/dt on the power cable.
du
I St = C K × -----dt
The interference voltage created in the susceptible equipment (circuit 2) depends
on:
du
U St = C K × Z 2 × -----dt
Note: The interference voltage created in the susceptible equipment is
proportional to the value of impedance in the susceptible equipment. And the
impedance increases with the frequency of the interference signal. This results in
the interrelationships.
l High impedance measurement transfer lines are more susceptible to
interference than low impedance circuits.
l The interference current increases with the frequency of the voltage that exists
in the interference capacity of the "connecting clamps".
l High coupling capacitances create a short circuit between the circuits that
influence one another for HF interferences.
73
EMC Basics
Coupling
capacitance CK
Coupling capacitance C K increases linearly with the distance that the two lines run
in parallel and decreases according to a algorithm with the increased cable spacing:
D
100
pF
m
d
CK
I
10
1
100
101
l
Distance that the lines run in parallel
d
Distance of the lines from one another
D
Line diameter
102
d/D
103
Realistic example values for coupling capacitance C K with a line diameter of d = 1
mm:
l Tightly packed cable: CK up to 100 pF/m
l Cable spacing 10 cm: CK = approx. 5 pF/m
Note: Starting with a distance of D = 20 cm, CK only decreases minimally.
74
EMC Basics
Radiating Coupling
Mechanism
When system components are excited by electromagnetic waves having wave
lengths of the measurements of these components, energy is radiated and is
transferred across the electromagnetic field to the receivers. Antennas which can be
made of loops, dipoles or single ground lines act as susceptible equipment.
Well known sources of interference are:
l Insufficiently shielded high frequency devices
l Radio and television
l Fluorescent lamps
l walkie-talkies, cellular telephones
Size of the
interference
The intensity of the excitement and radiation depends on the ratio between
measurement and wave length. The amount of received voltage can be estimated
at:
U 0 = E 0 × h eff
Character definitions
Character Meaning
U0
Received voltage in the susceptible equipment
E0
Electrical field strength at the receiver
heff
Effective antenna height
Note:
l The radiating coupling becomes interesting with interference signal frequencies
of 30 MHz and higher.
l The interference is at its strongest if the length of the "Antennas" are a multiple
of the wave length.
75
EMC Basics
Wave Influence
Mechanism
Wave influence is the combination of capacitive and inductive coupling of parallel
lines, if the wave lengths of the signals are within their measurements, i.e. with
highly frequent signals.
A progressive wave which creates an electric field and a magnetic field is now the
source of interference.
Current and voltage distribution on the line depend among other things on the
following values:
l Wave resistance of the line
l Termination resistance of the line
Reflection of the signal occurs on the line or at the end if the wave resistance at the
join is changed or if the wave resistance and the termination resistance are not the
same size. The reflections override the incoming wave.
Lines within the range of the wandering fields are susceptible equipment. The
coupling between the individual lines is done via the respective partial wave
resistances.
Size of the
interference
The amount of coupled interference voltage depends on the impedances of the
disturbed lines. References for ratio calculations have been developed in conductor
theory.
76
EMC Basics
Which measures for which type of coupling?
Measures
Depending on the type of spreading (coupling) of the interference, various measures
can be taken to decrease or neutralize it. Explanations for the individual measures
can be found in the next chapter:
Galvanic
coupling
Grounding
X
Electrical isolation
X
Inductive
coupling
Capacitive
coupling
Radiation
coupling
Wave
influences
Balancing circuits
X
X
X
Transposition of
outgoing and
return lines
X
X
X
Wiring
arrangements
X
X
X
Device
arrangement
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Shielding
Filtering
X
Cable selection
X
Wiring layout
X
X
77
EMC Basics
78
Basic EMC Measures
5
Overview
Introduction
Using knowledge about sources of interference and coupling mechanisms, we have
the following possibilities to reduce electromagnetic effects:
l Take measures against sources of interference that reduce the transmission of
disturbance
l Take measures to limit the spreading of disturbance
This chapter provides detailed descriptions about basic measures to take against
sources of interference, and measures to lessen their expansion (coupling).
You will need the information given in this chapter to understand EMC measures in
a system and for EMC compatible design, and also to understand installation
procedures.
A prerequisite for this chapter is knowledge about the types of sources of
interference, the superposition of interference and useful signals and about coupling
mechanisms.
What's in this
Chapter?
This chapter contains the following topics:
Topic
Page
EMC Measures for Grounding Systems
80
EMC Compatible Wiring
83
Balancing Circuits
83
Transposition
83
Room Arrangements
84
Cabling Arrangements
84
Shielding
84
Filtering
86
79
EMC Measures
EMC Measures for Grounding Systems
EMC functions of
the grounding
system
The grounding system has the following tasks with regard to EMC:
l Interference current dissipation
l Prevent couplings
l Maintaining shielding at specific potentials
The grounding system must fulfill these requirements without interfereing with the
device and wiring.
Note: Green-yellow equipment grounding conductors are not usually suitable for
these tasks. Grounding conductors can only dissipate low-frequency signals (50
...60 Hz), and do not guarantee equipotential bonding for high-frequency signals as
their impedance is too high.
Effect of
grounding
EMC measures
for grounding
systems
The galvanic coupling is affected by the ground connection. Disturbances can
spread via the grounding system across the entire plant if the grounding system is
poorly configured or bad connections are made.
The following EMC arrangements are available for grounding systems:
l Optimal selection and combination of grounding systems (point-to-point or
meshed) if necessary
l Meshed grounding: sufficiently small surface area of the loop between exposed
conductive parts
l Sufficient cross-section of the earth conductors low-resistance and lowinductance lines and therefore an effective equipotential bonding for low and high
frequency signals
l Good chassis connection to decrease the contact resistance
Types of
grounding
systems
Two types of grounding systems are used:
l S Type: Point-to-point
l M Type: Grid-type
Large plants use both grounding types in combination as they have varying
effectiveness depending on the application. The advantages and disadvantages of
each system are described below.
80
EMC Measures
S type grounding
system
With point-to-point grounding of reference conductors, every reference conductor to
be grounded in a circuit is only connected once to ground at a central point.
Point-to-point grounding system
S Type
ERP
Advantages and
disadvantages of
point-to-point
grounding
Advantages of point-to-point grounding for reference conductors
l Reference conductors cannot be coupled and disturbance caused by induced
voltages is not possible at low-frequencies
l At low-frequencies, no or only slightly different potential differences between
ground and reference conductor can occur.
Disadvantages of point-to-point grounding for reference conductors
l A point-to-point grounding system can only be achieved at high cost due to
additional isolation.
l High-frequency coupling are possible.
l Different conventional reference potentials can occur at high frequencies.
l Isolated arrangement of device chassis is required against the reference
conductor.
81
EMC Measures
Grounding
system type M
With grid type grounding, the reference conductors are connected multiple times to
the chassis connection. This creates a perfectly meshed system.
The connections are arranged between the devices ground, cable runs, existing or
under construction metal structures etc. Shielding, filtering devices return
conductors, etc. are directly connected to this cable.
Grid-type grounding system
Interconnecting System
Advantages and
disadvantages of
meshed
grounding
Advantages of meshed grounding for reference conductors
l Lower potential difference for high-frequency disturbance within the grounding
system
l No isolated arrangement of device chassis is required against the reference
conductor.
Disadvantages of meshed grounding for reference conductors
l Galvanic couplings between different circuits via common impedance and
currents is possible as a consequence of the induced voltage in the conductor
loop.
82
EMC Measures
EMC Compatible Wiring
Wiring rules
Electronic wiring must be done according to EMC compatibility. EMC measures
include:
l Balanced construction and balancing of unbalanced coupled interferences
l Low input impedances
l Limited working frequency bandwidth
l Careful wiring arrangement
l Correct chassis connections
l Avoidance of internal couplings
l EMC domain management of power supplies
Balancing Circuits
Balancing
Wiring
possibilities
The purpose of balancing circuits is to convert unsymmetrical coupled interferences
into symmetrical ones. Balanced interferences can therefore be suppressed by
differential amplifiers.
See also: Overlapping of Interference and Useful Signals on Wires, p. 57 .
The following wiring techniques can be used to balance circuits:
Additional resistors
Four conductor bundle
Twisting wires
Twisted
l
l
l
l
Transposition
Transposition
The transposition of outgoing and return conductors is done to suppress disturbance
by creating an inductive coupling in a circuit. Induced voltages in a successive
conductor loops are 180o out of sync and neutralize each other.
Transposition becomes more effective with increasingly number of loops.
A good figure is 30 loops per meter.
83
EMC Measures
Room Arrangements
Room
arrangements
from an EMC
point of view
Arranging components in a room with regard to EMC basically means that a
specified minimum distance between components must be maintained to avoid
capacitive, inductive and radiation coupling. This results in groupings of sources of
interference and susceptible equipment in a complete system. The field
configuration is the decisive factor for the distances required.
Cabling Arrangements
The role of
cables in EMC
Cables are used to transfer useful signals. At the same time they can also be an
interference source or pass on disturbance they have received. All forms of coupling
play a role here.
Principle of cable
categories
Cables used in a system are categorized according to the type of signals they carry.
The signals EMC performance is the deciding criterion.
You can roughly allocate cables into three categories or classes in an industrial
environment:
l Sensitive signal
l Insensitive signal, low interference potential
l Signal is an active source of interference
Categorization allows cables with different EMC performance can be laid separately
from each other.
There are the following options:
l Maintain distances between different categories
l Shield cables of different categories from each other
Shielding
Use of shields
Shielding is required if susceptible equipment and sources of interference cannot be
sufficiently distanced through room rearrangements.
Shield
A shield is a metal component that is placed between the source of interference and
the susceptible equipment. It influences the distribution between source and the
equipment. The coupling is minimized this way.
84
EMC Measures
Shielding types
There are several different types of shield that can be used:
Cable shield
Chassis as shield
Room shielding
Partition panel as shield
l
l
l
l
Shielding
effectiveness
The effectiveness of the shield depends on its mutual impedance The mutual
impedance must be as small as possible in order to achieve good shielding
effectiveness.
The smaller the mutual impedance is, the greater the leakage current can be.
Mutual
impedance of
different cable
shields
The following diagram shows the mutual impedance of different cable shields
depending on the frequency:
R
mΩ
m
Aluminium foil coiled
with plastic coating
1000
100
Single ply
10
1
Double ply
0.1
Double ply with
magnetic foil
0.01
Metal tube
0.001
1k
10k
100k
1M
10M
f [Hz]
85
EMC Measures
Shield grounding
The shield is connected to ground to dissipate the currents. Sufficiently large cross
sections are required for current dissipation since the current discharge can be very
large with expanded plant systems.
Double shielding
Shielding can be improved by using double shielding. The additional shield is
connected to ground at a suitable point.
Driven shield
Shielding can be improved by using a driven shield. This maintains the shield at the
potential of the signal voltage.
You can achieve this for example, by back coupling a repeater output. This also
means capacitive interference currents between the conductor and the internal
shield are avoided.
Filtering
Filter
A filter comprises components such as capacitors, chokes or ferrite cores and are
integrated in a circuit.
Filters should only let useful signals through and suppress undesired parts of the
transferred signal as much as possible.
Filters are used for different purposes:
l To protect the power supply network against interference through the devices
l Protect devices from interference from the power supply network
l Protect circuits against interferences from devices within the circuit
How filters work
Useful signals and undesired signals are superposed at the filters input, only the
useful signal is transferred to the output. The filtered out undesired signal is
dissipated via the ground connection.
UInput
Filter
Transferred signal
=
Useful signal + interference
86
UOutput
Transferred signal
=
Useful signal
EMC Measures
Filter types
Ferrite cores
There are the following filter types:
l Filter for common-mode interference
l Filter for differential mode disturbance
l Combined filter for differential and common-mode interferences
Ferrite cores are filters for high frequency common mode interferences. The are
made from materials with high magnetic permeability.
Ferrite cores work on two principles:
l Inductivity against common interference currents
l Absorption of the induced high frequency interference current using
simultaneous energy release (warming up)
87
EMC Measures
88
Earth and EMC Measures in
Automation Systems - System
Guidelines
III
Overview
Introduction
This section contains guidelines for EMC and earth measures in automated
systems. The measures are not product specific but generally apply to all modern
systems and machines in which PLC systems are used.
What's in this
Part?
This part contains the following chapters:
Chapter
Chapter Name
Page
6
Measures for the Entire System
7
Grounding, Earthing and Lightning Protection System
8
Power Supply
9
Cabinets and Machines
119
Cabling
131
10
91
95
115
89
Guidelines for the Entire System
90
Measures for the Entire System
6
Overview
Introduction
This sections contains guidelines for EMC measures that apply to the entire system
in which PLCs are used.
What's in this
Chapter?
This chapter contains the following topics:
Topic
Page
Measures to take at Sources of Interference
92
Guidelines for Arranging Devices
92
Protection against Electrostatic Discharge
93
91
Measures for the Entire System
Measures to take at Sources of Interference
Measures to take
at Sources of
Interference
Measures can be taken against sources of interference to suppress or reduce the
interference at its origin.
Measures can include the following:
l Suppressing switched inductive loads
l Reducing the influence of electrostatic discharges
l Avoiding influence of walkie talkies
l Avoiding influence of low frequency magnetic fields
l Avoiding influence of electron torches
Guidelines for Arranging Devices
Arrange devices
in zones of
differing
disturbance
climates
Zones of differing disturbances climates must be defined within the plant in which
devices are arranged according to their sensitivity or potential for interference.
These include fundamentally different zones:
l Process
l Control system
l Data processing with computer work stations
PLC system
Separation of the PLC system is enabled by being installed in cabinets or on
machine chassis. The guidelines for cabinet setups can be found in Guidelines for
Arranging the Device in the Cabinet or a Machine, p. 120.
Process
The processing plant with interfering components forms its own zone.
Sensitive cables and devices for process data acquisition and control (that are
always in this zone) must be shielded.
Strong interference affects high current equipment above all through their magnetic
fields, such as:
l High current equipment in energy supply company systems
l Melting in chemical plants
l Transformers
l Energy distribution from manufacturing plants
92
Measures for the Entire System
Computer work
stations
Computer work stations should be placed in separate, shielded rooms that are
equipped with close-mesh equipotential bonding in the floor, see Guidelines for the
Grounding System in Buildings, p. 98.
In reality, it is often necessary to install computer work stations near the production
line. Monitors near high current equipment can have such large problems with
interference that work is no longer possible with them.
If the magnetic fields present exceed the values recommended for monitor use,
counter measures must be taken such as:
l Increase the distance from the source of the interference
l Shielding of the source of interference
l Use of plasma monitors
l Shielding of monitor screens
Protection against Electrostatic Discharge
How
electrostatic
charge and
discharge works
Computers, central control and operating devices are often installed in rooms with
insulated flooring. Dry weather and low relative humidity lead to high electrostatic
charge on the operating personnel that can lead to damaging discharges on
devices:
l If you wear rubber soled shoes when walking across an insulated carpet of
another material (synthetics) an overcharge occurs on the soles of the shoes
because two different insulated materials separate from each other.
l Since the human body can be considered as conductive, an influence charge
accumulates on the human body through the charged shoe soles, i.e. positive
and negative charge carriers are separated. This charge accumulates with every
step.
l If metal objects or devices are now contacted, a discharge spark with a powerful
current pulse is created, whereby the discharged energy is proportional to the
square of the electrostatic charge.
Guidelines for
protection
against
electrostatic
discharges
Observe the following guidelines to avoid damage to operating equipment:
l
l
l
l
Use conductive flooring with a contact resistance between 105 and 109 Ohm.
Do not treat smooth surfaces with wax, use anti-static cleaning products instead.
Spray carpets with anti-static conditioners.
Increase the relative humidity using a humidifier or air conditioning to a value
above 50%.
93
Measures for the Entire System
94
Grounding, Earthing and
Lightning Protection System
7
Overview
Introduction
This sections contains guidelines for the configuration of grounding, earthing and
lightning protection systems in a plant in which PLC systems are used.
What's in this
Chapter?
This chapter contains the following topics:
Topic
Combination of Earthing, Grounding and Lightning Protection and Highest
Safety Requirements
Guidelines for the Grounding System in Buildings
Page
96
98
Guidelines for Local Grounding for Devices and Machines
100
Guidelines for Installing an Island Grounding System
101
Guidelines for the Earthing System and Grounding System
103
Guidelines for Lightning and Overvoltage Protection
106
Guidelines for Grounding and Earthing for Systems between Buildings
108
Guidelines for Creating Ground Connections
109
95
Grounding, Earthing, Lightning Protection
Combination of Earthing, Grounding and Lightning Protection and Highest
Safety Requirements
Overview
Highest safety
regulations
The earthing, grounding and lightning protection systems in a building must be
designed together as they are always combined with each other.
The tasks of the three systems are as follows:
l Grounding system: The grounding system is responsible for ensuring an
equipotential surface for the plant. The connection of the grounding points with
the earthing system means the grounding system has an important safety aspect.
l Earthing system: The earthing system creates the electrical connection to earth
that serves both as the equipotential bonding for the system and also for safety.
Different safety and EMC requirements are required for the different system types
TT, TN and IT systems.
l Lightning protection system: The lightning protection system protects the plant
and personnel against lightning strikes.
The two following safety regulations must be observed when configuring the system:
l Personal injury must be avoided during normal operation and in the event of an
error. This means it must be avoided that people can come into contact with
components that carry dangerous voltages.
Dangerous voltages are:
l A.C. voltage with a peak value of 42.4 V and higher
l D.C. voltage of 60 V and higher.
l In the event of differing safety and EMC requirements, the safety requirements
must always have priority.
Safety before
EMC!
96
Note: When configuring the earthing and grounding systems, always give safety
requirements priority over EMC if the requirements are conflicting!
Grounding, Earthing, Lightning Protection
Configuration
example
The illustration shows an overview of how earthing, grounding and lightning
protection systems can be implemented in a building while taking EMC into
consideration:
Lightning conductor
Computer island, room
<2m
Vertical
Earthing
Metal housing
Metal straps
<3m
1m
< 10 m
Grounding strip (buried)
Crows foot
Principle of an earthing network
97
Grounding, Earthing, Lightning Protection
Guidelines for the Grounding System in Buildings
Grounding
systems for
expanded
systems
We differentiate between a main grounding system that incorporates the entire plant
and the local equipotential bonding for expanded systems:
l Main system grounding system: Grounding system that incorporates the entire
building
l Local grounding system: Grounding system on the local level (device, machine,
cabinet)
Guidelines for a
building
grounding
system
EMC guidelines must be followed for the main grounding system in an expanded
system within a building:
l Each floor must have an earth plane as well as a surrounding grounding strip.
This includes the following: welded, steel mats in the concrete bed, hollow floors
with copper wire grids etc.
l The distance between earth conductors must be greater than the following
values:
l Production hall: 3 ... 5 m
l Areas with computers and sensitive measuring devices: < 2 m
l All metallic structures within a building should be connected to the network.
l Metallic framework
l Concrete reinforcements welded together
l Metal piping
l Cable ducts
l Conveyor belts
l Metal door frames
l Grids
l ...
Note: Earth cables may not be longer than 10/(frequency in MHz). Earth cables
that are too long cause undefined potentials in the system, unavoidably lead to
potential differences between devices and allow undesired currents.
98
Grounding, Earthing, Lightning Protection
Example: Earth
plane in a
building
The following illustration shows an example of EMC compatible installation of a
grounding system in an industrial building
Cabinet for
high power
Cabinet for
low power
Channel for
power cables
Channel for
low power cable
Channel for
low power cable
Concrete reinforcing steel
Grounding strip
5m
Ground connection
99
Grounding, Earthing, Lightning Protection
Guidelines for Local Grounding for Devices and Machines
Local grounding
In addition to the grounding system for the entire system, expanded systems in a
plant must also be equipped with local grounding for devices and machines to
ensure a good equipotential bonding. The local grounding systems are connected
to the plant grounding system.
Guidelines for
local grounding
The following guidelines should be observed to achieve a good local equipotential
bonding:
l An unbroken link (daisy chaining) should be made between all metal device and
machine structures:
l Switching cabinet
l Earth plane plate on cabinet floor
l Cable duct
l Pipe and sheathed cable lines
l Supporting components and metal chassis from machines, motors etc.
l Special earth conductors may be required to complete the ground connection.
Example: Both ends of a cable conductor which is not used are connected to
ground.
l The local ground connection must be connected to the main system network,
whereby a maximum number of distributed ground connections should be made.
100
Grounding, Earthing, Lightning Protection
Guidelines for Installing an Island Grounding System
Definition: Island
grounding
system
A grounding system does not necessarily have to cover the entire building. In an
industrial environment the electrical equipment is usually grouped into specific areas
or islands.
A grounding cell is created by daisy chaining the grounding points. This can be
cabinets, machine chassis and metallic cable ducts:
Horizontal cable duct
Plant
Vertical cable duct
Metal straps
Note: Sensor and actuator cables outside of these islands must shielded with
great care!
101
Grounding, Earthing, Lightning Protection
Example of daisy
chaining
Example: Two of more cabinets or machine chassis can be connected to an island
by daisy chaining their grounding points.
Ground connections for cabinets and constructive components:
Grounding connection points
Guidelines and
recommendations for island
grounding
systems
Recommendations for creating a grounding cell:
l An island may not be larger than 3 ... 5 m2.
l "Conductive" false floors can be used to create an effective island grounding
system. For reasons of practicality only one of three supports needs to be
l
l
l
l
l
102
connected. This gives you a cell of 1.80 m2.
The connections can be made using copper rod, short, fat bolts or with grounding
strips.
Where possible a direct positive fit contact should be made, for example, for the
connection of metal cable ducts.
When two chassis or cabinets are installed side by side, they should be
connected directly to each other at at least two points, i.e. above and below.
Ensure that paint or any other coating does not affect the electrical contact. The
use of lock washers is recommended.
The grounding components (strips, bolts...) may not be longer than 50 cm.
Grounding, Earthing, Lightning Protection
Guidelines for the Earthing System and Grounding System
Scope of the
grounding
system
EMC
performance and
guidelines for the
grounding
system
The grounding system for an electrical system creates the connection to earth and
must meet the following requirements:
l Discharge the voltage from touchable metallic system parts (chassis) to protect
people from electric shocks
l Discharge over-currents from direct lightning strikes to earth
l Discharge induced currents from atmospheric discharges between two points of
a power transmission line to earth
System
EMC performance
TT
Conditionally suitable
Between the ground connection of the
primary distribution network and the
leakage current from the electrical
system, that are caused by ground
faults within the system. As with
transient currents, potential difference
occurs due to the leakage current from
devices. These transient currents can
lead to faulty couplings or even faults
within the system.
A corrective measure here is a
equipotential bonding conductor
between the devices connected
directly to earth. These measures
basically convert the TT system into a
TN-S system.
TN-C
TN-C-S
Bad
Because the functions and protective
earth conductor are combined in TN-C
and TN-C-S systems, current
feedback occurs on the PEN
conductors during normal operation.
Current feedback from devices via the
PEN conductors can lead to faulty
couplings.
Guidelines for use
l
l
l
l
l
l
ELCB for personnel safety is
required
Surge arresters should be installed
(distributed over power
transmission lines)
This type of network requires
corresponding measures for
devices with high leakage current
potential that are located behind the
ELCB in the outgoing direction
Ensure an unobstructed path for
the PEN conductor when
expanding the system!
Because of the high current in the
PEN conductor this system is not
permitted in areas of particularly
dangerous sources.
If devices with high total harmonic
distortion are operated in a system,
this type of system is not
recommended.
103
Grounding, Earthing, Lightning Protection
System
EMC performance
TN-S
Very good
The TN-S system is the best solution
from an EMC point of view. The PE
conductors have no power in normal
operation.
IT
Bad
Note: The IT system is recommended
as intrinsically safe for safety matters
since no electric arcs can occur.
Guidelines for use
l
l
l
l
l
l
l
104
Ensure an unobstructed path for
the PE conductor when expanding
the system!
A 500 mA ELCB must be installed
for protection against fire.
Corresponding measures are
required for devices with high
leakage current potential that are
located behind the ELCB in the
outgoing direction.
Ensure an unobstructed path for
the PE conductor when expanding
the system!
Filters for asymmetric interference
currents cannot be installed.
Good EMC is only provided within
systems (buildings) where all
devices are connected to the same
grounding device.
If circumstances dictate that the
system must be divided to limit the
cable lengths and leakage currents
Grounding, Earthing, Lightning Protection
Recommended
grounding
system
connection
scheme
The following illustration shows a typical connection scheme for a grounding system:
A
A
D
E
F
E
C
B
A
Lightning arrester down-lead
B
Underground meshed earthing system with reinforcement at foot of the down-lead
C
System ground connection, connected to the equipotential bonding strip, to which the PE
conductor or PEN conductor are connected in turn
D
Earthing system for a system section with integral metallic structures or additional ground
connections (E)
E
Interconnection between the lightning arrester down-lead and the earthing system as well
as other metal structures in the vicinity
Note: A single, specifically laid ground connection is required for every electrical
system and is in itself sufficient.
105
Grounding, Earthing, Lightning Protection
Guidelines for Lightning and Overvoltage Protection
Definition:
External and
internal lightning
protection
We can make a differentiation between external and internal lightning protection for
a building containing an electrical system:
l External lightning protection: External lightning protection is the installation of
air terminations that discharge the lightning current to the earth via a suitable
earthing system.
l Internal lightning protection, overvoltage protection: Internal lightning
protection comprises measures taken against the effects of the lightning strike
and its electrical and magnetic fields on metal installations and electrical systems.
This means primarily the measures taken against equipotential bonding and
overvoltage protection.
Guidelines for
lightning
protection
The following guidelines should be observed for lightning and overvoltage
protection:
l The system should be divided into lightning protection zones with staggered
protective measures, see table below.
l All conductive parts that enter a zone should be connected to one another and
with equipotential bonding strip at the edges of the individual zones.
l The shielding for the zones should also be connected to these strips.
l In addition, a connection to equipotential bonding strips to higher and lower
priority protection zones.
Note: All lines going in and out of the system to be protected must be connected
to the earthing system directly via spark gaps or protective devices (lightning
arrestors). In the event of a lightning strike the potential of the system struck
increases temporarily but no dangerous potential difference occurs within the
system.
106
Grounding, Earthing, Lightning Protection
Lightning
protection zones
Dividing the system into lightning protection zones with staggered protective
measures is done as follows:
Zone
Definition
Measures
0
All objects are exposed to a direct
lightning strike.
External lightning protection via surge
arresters and down-leads to the
earthing system
1
The objects are not exposed to direct Building shield (steel reinforcement)
lightning strikes, the magnetic field
dampened depending on the
shielding present.
2 and
additional
The objects are not exposed to direct Room shield using steel mash mat
lightning strikes, the magnetic field is Device shield (metal housing)
better dampened, dissipated currents Lightning conductor
are reduced further.
zones(1)
1: If necessary, additional zones with further reduced currents and electromagnetic fields
must be installed.
The following illustration shows an example of the division of a building into lightning
protection zones
Lightning protection zone 0 (outside)
Lightning protection zone 1
Exterior
Lightning protection
Lightning protection zone 2
Building shield
(steel reinforcement)
Lightning protection zone
Device shield
(metal housing)
Device
Room shield
(steel reinforcement)
PAS
Surgedeflector
Cable
PAS
Foundation ground
Lightning conductor
107
Grounding, Earthing, Lightning Protection
Guidelines for Grounding and Earthing for Systems between Buildings
Problems that
arise with
systems that
encompass more
than one building
A system is not always accommodated within one building, but can stretch across
two or more buildings. This means there are power and/or signal cables going from
one building to another.
If both buildings have independent ground connections and grounding systems, it
can lead to an interfering potential difference between the end points of a line
running between buildings.
In the event of a lightning strike on one of the buildings this potential difference can
become so high that destructive transient currents can be sent down the line. People
and animals can also be endangered if parts of the buildings can be touched
simultaneously.
Guidelines for
grounding and
earthing between
buildings
When a system is installed across more than one building the following guidelines
for grounding and earthing must be observed:
l Earthed parts that can be touched simultaneously must be connected to the
same earth connection.
l A suitable potential compensation lead must be installed between the buildings
grounding systems that is capable of dissipating transient currents caused by
lightning strikes.
Note: All lines going in and out of the system to be protected must be connected
to the earthing system directly via spark gaps or protective devices (lightning
arrestors). In the event of a lightning strike the potential of the system struck
increases temporarily but no dangerous potential difference occurs within the
system.
108
Grounding, Earthing, Lightning Protection
Guidelines for Creating Ground Connections
Guidelines for a
good ground
connection
The following guidelines should be followed when creating ground connections:
l Ground connections must be made with great care and the operating demands
of the system must not be impaired.
l High contact resistance with the ground connection must be avoided by taking
the following measures:
l Galvanized mounting plates and fixing components must be used
l Remove painted or coatings from contact points and protect from corrosion
with electrically conductive special grease
l Bolt on metal pieces directly, without additional electrical conductors, e.g.
cable ducts
l Daisy chaining of earth busbars and welded or bolted on grounding strips
(instead of flexible grounding cables)
Install earth
busbars,
grounding strips
Daisy chaining of earth busbars and welded or bolted on grounding strips (instead
of flexible grounding cables)
Earth busbar
Better
L
I
PE - PEN
Yellow-green equipment
grounding conductor
Grounding strip
L
<3
I
109
Grounding, Earthing, Lightning Protection
Example:
Cabinet door
Use grounding strips instead of a flexible earth cable for the connection between the
cabinet door and the cabinet housing
1
Flexible earth cable
2
3
1
Grounding strip
110
Grounding, Earthing, Lightning Protection
Remove all
coatings
Remove painted or coatings from contact points and protect from corrosion with
electrically conductive special grease
Create metallic
contact!
Painting
I < 10 cm
Painting
111
Grounding, Earthing, Lightning Protection
Direct bonding
by bolted
fastening for
metallic parts
112
Bolt on metal pieces directly, without additional electrical conductors, e.g. cable
ducts
Grounding, Earthing, Lightning Protection
Ground
connection for
cable shields
The following illustration shows how to create a ground connection for cable shields.
Acceptable
Grounding strip
Bad
Good
Earth plane plate in the cabinet
Excellent
Cabinet
Note: The ground connection for cable shields must always run through the entire
cable.
113
Grounding, Earthing, Lightning Protection
114
Power Supply
8
Overview
Introduction
This sections contains guidelines for the configuration and layout of the power
supply for a system in which PLC systems are used.
What's in this
Chapter?
This chapter contains the following topics:
Topic
Page
How to Plan the Power Supply Plant
116
Guidelines for the Power Supply
117
115
Power Supply
How to Plan the Power Supply Plant
Potential
disturbances in
the power supply
network
The power supply network can itself be the source of continuous and intermittent
interference. Disturbances in the power supply can already be present in open
networks at the entry to the system. Further disturbances can be introduced by
devices in the system that are connected to the power supply.
Procedure for
meeting
technical
specifications
Proceed as follows to create the technical specifications for the power supply:
116
Step
Action
1
Categorize the potential upstream circuit disturbance (characteristics,
strength, frequency).
2
Catalog the different devices to be powered as well as the types of disturbance
created by them that can affect the functioning of the system.
3
Assess the effects of the disturbance on the system.
4
Evaluate the effects (are the consequences bearable?).
5
The evaluation of the effects of disturbances is then used to create the
technical specifications for the power supply. This enables you to determine
required properties of the electrical power supply to be installed.
Power Supply
Guidelines for the Power Supply
General
guidelines
The following guidelines should be observed regarding the power supply:
l A surge limiter must be installed at the junction where the flex enters the building.
l Disturbances to the mains power are dampened by industrial line filters installed
at the entrance to the system.
l Sensitive devices are protected by surge limiters and surge arresters at the input
feed.
l Transformers can also be used as filters. For high frequency disturbances the
transformer must be equipped with single, or preferably double, shielding.
Example:
Solution for the
power supply
The following illustration shows an example of filtering the mains power by using a
double isolated transformer:
Mains
Shielding
L1
L1
N
L2
A.C. power supply cable
L2
L3
L3
Earthing point for
Transformers
Surge arrestor
PE
Earthing at infeed point
Earthing
Central conductor
Note: A good ground connection is vital when installing transformers. The
transformer housing must be bolted to a conductive earth plane.
117
Power Supply
Guidelines for
partitioning in
the system
The power supplies for the individual devices should be wired as point-to-point from
the line entry:
Disturbing station
Mains
Sensitive
Device
Disturbing station
Mains
d
Sensitive
Device
Separate power supplies must be provided if extremely sensitive and high
interference devices are used concurrently in the same power supply system:
Mains
Disturbing station
Sensitive Device
Devices with high inference capabilities must be connected as close as possible to
the line entry and sensitive devices connected at a distance from the line entry:
Distinctive disturbance
station High power
118
Negligible disturbance
station Medium power
Sensitive device
Low power
Cabinets and Machines
9
Overview
Introduction
This section contains guidelines for the setup of cabinets from an EMC point of view,
and for the installation of specific components.
Some of the guidelines are also applicable for machines that are equipped with PLC
controllers, whereby the machine housing can be equated with cabinet housing.
What's in this
Chapter?
This chapter contains the following topics:
Topic
Page
Guidelines for Arranging the Device in the Cabinet or a Machine
120
Guidelines for Grounding and Earthing in the Cabinet
122
Guidelines for the Reference Conductor System in the Cabinet
125
Guidelines for Cabling in the Cabinet
126
Guidelines for Materials and Lighting in the Cabinet
127
Guidelines for Installing Filters in the Cabinet
128
119
Cabinet
Guidelines for Arranging the Device in the Cabinet or a Machine
EMC Domain
Sensitive and interfering electrical components and cables must be kept separate.
This is possible by housing them in separate cabinets or by using shielded partition
panels.
The cabinet must be divided into EMC domains:
l Areas of different interference levels (EMC domains) must be made in the
cabinet. This means that sources of interference and susceptible equipment must
be kept separate.
l The EMC domains must be decoupled.
Note: For machines:
NC controllers, PLCs and drives can be installed in a cabinet or machine housing
under the following circumstances:
l The drive cable must be shielded.
l The guidelines for cabling must be observed, see Cabling, p. 131.
Isolation of
Inductances
120
Isolation by using partition panels is necessary for the part of the cabinet where
sources of inductance are mounted. The partition panel must have a good
connection to the cabinet (ground).
Examples of such sources of inductance are:
l Transformers
l Valves
l Contactors
Cabinet
Example for setting up small cabinets: partitioning using partition panels that are
connected to ground at several points, reduces interference influences
High power
Low power
Partition panel
Example: EMC
domains
separated by
partition panels
High performance
components
Mains
Actuator
Transducer
Probes
Detectors
121
Cabinet
Solution: EMC
domains in two
cabinets
Example for setting up large cabinets: A separate cabinet is provided for the power
and control sections; cable connections are made in a metal cable channel:
Low
Power
High
Power
Metallic cable duct
Guidelines for Grounding and Earthing in the Cabinet
Guidelines for
Earthing and
Grounding in the
Cabinet
The following guidelines should be observed when grounding a cabinet:
l An unpainted earth reference plane or rail must be installed on the floor of the
cabinet for the conventional reference potential.
l All metal parts of the cabinet are connected with each other.
l The metal housing of the cabinet must be integrated in the higher level earthing
system.
l All protective grounding conductor must be earthed.
122
Cabinet
Constructing
earth and ground
in the cabinet
The following illustration shows how the earth and grounding system is constructed
in the cabinet.
HS
MA
M
MA
EB
FE
PE
EB Adjacent cabinet or jig
FE The functional earth, e.g. the iron beam of the hall, water or heating supply pipes, or neutral
earthing for the hall
HS Mounting rail for installing the module backplane or the installation accessories
M Reference conductor system or reference conductor rail (massive copper busbar or
bridged terminal block)
MA Grounding (earth reference plane or rail) that is used as the functional earth
PE Protective earth PE, via protective earth choke
123
Cabinet
Guidelines for
installing a
ground
connection in the
cabinet
124
The following guidelines should be observed when installing a ground connection in
a cabinet:
l An unpainted earth reference plane or rail must be installed on the floor of the
cabinet for the common reference potential.
l The sheet or metal grid that acts as the earth reference plane or rail is connected
to the cabinets metal housing at several points that is integrated with the systems
ground connection.
l All electrical components (filters etc.) are bolted directly to this earth reference
plane or rail.
l All cables are fixed straight through this earth reference plane/rail.
l The all-around contact of the cable shield is created using locknuts that are bolted
straight through the earth reference plane/rail.
l All these electrical connections should be made with utmost care to achieve a low
resistance connection.
Cabinet
Guidelines for the Reference Conductor System in the Cabinet
Reference
conductor
system
The cabinet contains different reference conductor systems that are connected to
one another:
l An unpainted earth reference plane must be installed on the floor of the cabinet
as the common reference potential.
l The reference conductor system for the following areas must be separated from
one another:
l Analog part (with point-to-point arranged reference conductors)
l Digital part (with meshed reference conductors)
l Power circuit (usually with point-to-point arranged reference conductors)
l The galvanic coupling for the reference conductor system must be minimized.
Example:
Reference
conductor
system
Example of partitioning the reference conductor system and its galvanic isolation:
Analog part
Conventional reference potential point-to-point
Digital part
Meshed conventional reference potential
Back-up capacitor
Power circuit
Conventional reference potential point-to-point
Common "reference point"
Power supply
125
Cabinet
Guidelines for Cabling in the Cabinet
Guidelines for
Cabling
The following guidelines apply when cabling the cabinet:
l As with external cabling, the cabling guidelines also apply to cables inside the
cabinet, Cabling, p. 131.
l Conductive coupling between the interference current dissipation of filters and
cable shields with the reference conductor system must be avoided.
l For analog process signals, shielded twisted outgoing and return conductors
should be selected.
Guidelines for
cable ducts in
the cabinet
Guidelines for
installing cables
The following guidelines must be observed when running and combining cables in
the cable ducts:
l 115/230 VAC mains and signal lines and 24/60 VDC signal lines must be laid in
different cable ducts. The distance between the ducts must be at least 100 mm.
Unavoidable crossing must be at right angles.
l Digital signal lines (24/50 VDC) may be unshielded in a common cable channel.
l The following cables can be combined in a cable duct:
l Shielded bus cable
l Shielded analog process signal cable
l Unshielded 24/60 VDC signal lines
The following guidelines should be observed when installing cables in cabinets:
l The selection of the housing lead through must be made very carefully as this
ensures connection with the earthing system.
l Interfering cables must be filtered before entering the cabinet.
Guidelines for
filters
The following guidelines should be observed when using filters:
l The filter must have a good conductive ground connection.
l The filters input line may not be laid together with the filters output line or with
other signal and supply lines.
l When mounting the filter near a cable entrance (distance from floor or wall < 100
mm), the line to the filter is only twisted.
l When mounting a filter further than 100 mm away from the cable entrance, the
line through the cabinet must be twisted and shielded.
126
Cabinet
Guidelines for Materials and Lighting in the Cabinet
Guidelines for
materials
Suitable metal combinations must be used to ensure a long term highly conductive
connection between the metal parts that form the cabinet:
The metals to be connected should be selected according to the electro-chemical
series of metals, to reduce the potential differences to a maximum of 0.5 V. This also
applies when selecting the connection components such as screws, stay washers,
rivets etc).
Guidelines for
Lighting
Fluorescent tubes may not be used in series to light cabinets.
The following lights can be used:
l Light bulbs
l Energy saving lamps
l Fluorescent tubes with electronic starters
127
Cabinet
Guidelines for Installing Filters in the Cabinet
Installation
guidelines for
filters
The following guidelines should be observed when installing filters in a cabinet:
l Filter should be installed directly to the cable input in the cabinet if possible.
l Filters are screwed directly to the unpainted wall or to the earth reference plane
on the base of the cabinet.
l The filters input and output leads may not be installed in parallel.
l The filters cable must be wired directly across the cabinet wall or floor.
Note: Pay attention to leakage current from the filter! Special safety measures
must be taken for leakage currents above AC 3.5 mA/DC 10 mA. Refer to the
standards that apply in your country.
Example:
Excellent
Installation
Locations
128
The following illustration shows two good solutions for installing a filter in a cabinet:
Cabinet
Example:
Excellent
Installation
The following illustration shows an excellent filter installation:
Power
Supply
Filter
Paint = INSULATION
Output:
- to the actuator
- to the machine
129
Cabinet
130
Cabling
10
Overview
Introduction
This sections contains guidelines for cabling systems in which PLC systems are
used.
What's in this
Chapter?
This chapter contains the following topics:
Topic
Page
Classification of Signals according to their EMC Performance
132
Guidelines for Selecting Cables
133
Guidelines for Combining Signals in Cables, Conductor Bundles and
Connectors
134
Guidelines for Laying Cables in Parallel and Crossing Cables
135
Guidelines for Creating the Ground Connection for Cable Shielding
136
Guidelines for Grounding Unused Conductors
139
Guidelines for Installing Cables
139
Guidelines for Cable Ducts
141
Guidelines for Cables between Buildings
144
131
Cabling
Classification of Signals according to their EMC Performance
Reasons for the
classification
In an industrial environment, signals are classified in four categories according to
their EMC performance. This classification is required for the application of cabling
rules.
Classification of
signals
The following table shows the classification of signals according to their EMC
performance:
Classification
EMC
performance
Class 1
Sensitive
Signal is very
sensitive.
Class 2
Slightly sensitive
Signal is
sensitive.
Can disturb class
1 cables.
Class 3
Slightly interfering
Class 4
Interfering
132
Signal disturbs
class 1 and 2
cables
Signal disturbs
other classes
signals
Example of a circuit or device with cables in
this class
l
l
l
l
l
l
l
l
l
l
l
l
Low level circuits with analog output,
instrument transformer ...
Measuring circuit (probes, instrument
transformer ...)
Low-level digital circuits (bus ...)
Low-level circuits with digital output,
(instrument transformer ...)
Control circuit for resistive load
Low-level d.c. power supplies
Control circuit for inductive loads (relay,
contactor, coils, inverters ...) with
corresponding protection
A.C. power supplies
Main power supplies for high power devices
Welding machine
Power circuits in general
Electronic speed controller, switching power
supplies ...
Cabling
Guidelines for Selecting Cables
Guidelines for
Selecting Cables
The following guidelines should be observed when selecting cables for use in an
industrial environment:
l Use cables with twisted outgoing and return conductors.
l For analog signals, cables with shielded out and return conductors and braided
shields should be used.
Use cables with double shielding for analog process signals outside of buildings.
l For high frequency radiated interference (5-30 Mhz), use cables with braided
shields.
l Use shielded cables for interfering signals (class 4); additional shielding by
installing cables through metal tubes or metal cable channels.
Example for
class 1 signals
Example for the implementation of cables for class 1 signals (sensitive)
Shielded
twisted two wire cable
Example for
class 2 signals
Shielded cable
with additional
Shielding
Example for the implementation of cables for class 2 signals (slightly sensitive):
Unifilar
Conductor
Unused
Conductor
133
Cabling
Example for
class 3 signals
Example for the implementation of cables for class 3 signals (slightly interfering):
Example for
class 4 signals
Example for the implementation of cables for class 4 signals (interfering):
Metallic cable duct
Metal tube
Guidelines for Combining Signals in Cables, Conductor Bundles
and Connectors
Combination of
signals in cables
and conductor
bundles
Only signals of the same class may be combined in a cable or conductor bundle.
Combination of
signals in
connectors
The same connector may not be used for signals from different classes.
Analog and digital signals can be combined in a connector if a row of pins with 0 V
connections is present between them.
134
Cabling
Guidelines for Laying Cables in Parallel and Crossing Cables
> 5 cm
> 10-20 cm
> 10-20 cm
Class 4* (interfering)
The following illustration shows the recommended working distances between
shielded cables with signals from different classes for parallel installation up to 30
m. The longer the distance for the parallel cabling, the greater the working distance
to be selected.
Class 3* (slightly interfering)
Recommended
working
clearances
Class 2* (low sensitivity)
The following guidelines should be observed for parallel cabling with signals of
different classes:
l Unshielded cables with signals from different classes should only be installed
over the shortest distance possible.
l Parallel cabling of unshielded cables with signals from different classes should be
installed with the largest possible working clearance.
l Shielded cables should be used if cables with different signal classes are to be
installed in parallel over distances of more than 30 m, or if the working clearance
can not be guaranteed.
Class 1* (sensitive)
Guidelines for
Parallel Cabling
Earth reference
plane
> 50 cm
> 50 cm
>1m
135
Cabling
90°
3
90°
Cla
3
ss
Cl a
4
ss
ss
Cl a
Class 2
Cla
ss 2
ss
Cl a
> 20 cm
Cables that carry different class signals must cross at right angles.
> 20 cm
Guidelines for
crossing cables
4
Guidelines for Creating the Ground Connection for Cable Shielding
Guidelines for
selecting the
method of
connection
Note: Always avoid cable shielding without a ground connection. This type of
connection is practically useless from an EMC point of view and cannot be
permitted for safety reasons if contact protection is not provided.
The table shows how the cable shield should be connected to ground depending on
the application:
Application
Shielded analog measuring circuit in the
cabinet
Shielded analog measuring circuits outside
of cabinets in closed buildings
Cable shield ground connection
l
l
l
l
l
136
Ground connections are usually found on
one side of the cabinet outlet
Both ends of the cable shielding ground
for extreme levels of disturbance
If only capacitive electrical interference is
to be reckoned with: single cable
shielding ground connection
If the signal line is setup with highfrequency influences: double sided cable
shielding ground connection
If the signal line is long: in addition to
double ground connections along the
cable length, further ground connections
at intervals from 10 ... 15 m
Cabling
Long lines
For long shielded lines, several ground connections at intervals of 10 ... 15 m along
the length of the cable are recommended:
Earth reference plane
or
Earth busbar
with link
to chassis
L < 10 - 15 m
137
Cabling
Characteristics
of the connection
methods
The shielding ground connection is very important for the shielding effectiveness.
The following ground connection options have differing effectiveness:
Cable shield ground
connection
Ground connection on
both ends of the cable
Extremely effective
Effectiveness and advantages Restrictions
l
l
l
l
l
Ground connection on
only one end of the
cable
Average shielding
effectiveness
l
l
Very effective against
external disturbances (high
and low-frequency)
Very good shielding
effectiveness also against
resonance frequency on the
cable
No potential difference
between cable and ground
Enables common laying of
cables that feed different
class signals
Very good suppression of
high-frequency disturbances
Enables protection of
isolated lines (instrument
transformer, ...) against lowfrequency electric fields
Enables buzz to be avoided
(= low-frequency
disturbance)
l
l
l
l
Shielding without
ground connection
Not recommended
l
Limits the capacitive coupling
l
l
l
138
Ground-fault current can be
induced in high-frequency
signals with high
interference-field strength for
long cables (>50 m).
Ineffective against external
disturbances caused by highfrequency electric fields
The shielding can cause
resonance due to the
antenna effect. This means
the disturbance is greater
than when shielding is
present!
Potential difference between
the shielding and the ground
connection at the unearthed
end; danger in the event of
contact!
Ineffective against external
disturbances (all
frequencies)
Ineffective against magnetic
fields
Potential difference between
the shielding and the ground
connection; Danger in the
event of contact!
Cabling
Guidelines for Grounding Unused Conductors
Guidelines for
unused
conductors
Free or unused cable conductors must be connected to ground at both ends.
The following illustration shows how unused conductors can be connected to
ground.
Guidelines for Installing Cables
Avoiding loops
between
exposed
conductive parts
To avoid loop between exposed conductive parts all cables must be installed near
ground connections or ground cables.
The illustration shows an example of how cables are installed near ground
connections:
Cable
Device A
Device B
Earth reference plane
Good
Cable
Ground connection
Device A
Device B
VERY GOOD
Cable
Earth reference plane
139
Cabling
Installing
outgoing and
return
conductors next
to each other
Outgoing and return conductors must always be installed close to each other.
The smallest possible intervals are guaranteed across the total run length by using
2-wire twisted wire cables.
The illustration shows how out and return conductors are installed closely next to
each other. Parallel installation is only possible for signals of the same class.
Power
supply
Power
supply
Machine
Machine
Signal of the same class*
140
Signal of the same class*
Cabling
Guidelines for Cable Ducts
Guidelines for
arranging the
cables in cable
channels
Sensitive cables (classes 1 and 2) must be installed in the corners of the cable duct:
Guidelines for
connecting cable
ducts
Connecting cable ducts must be carried out when necessary i.e. direct bonding by
bolted fastening.
Note: The earthing of cable ducts must be carried out when necessary, see Direct
bonding by bolted fastening for metallic parts, p. 112.
Non metallic
cable ducts
Note: Cable ducts that are not electrically conductive such as PVC tubes, plastic
skirting boards or similar, are not recommended as they offer no shielding. For
example, they can be used in existing systems but only with a maximum run length
of 3 m.
141
Cabling
Recommended
cable ducts
142
The following cable ducts are recommended:
Steel conduit
Steel cable duct
Trunking
Steel cable duct
Buried cable
Cable tray or steel trays
Cabling
Underground channel, closed
Underground cable channel,
closed form
Underground channel, open or ventilated
Underground cable channel,
open or ventilated
143
Cabling
Guidelines for Cables between Buildings
Problems that
can arise with
outside cables
If signal cables are laid outside of buildings the following points should be noted:
l A potential difference can exist between buildings that can created an error
during transfer.
l Cables between buildings can carry a higher current in the event of a sudden
increase in the potential of a building due to a lightning strike.
Guidelines for
outside cables
For cables that are laid outside of buildings, the following guidelines should be
observed:
l Shielded cables must be used.
l The shield must be capable of carrying the current and must be grounded at both
ends.
If the shield cannot carry the current, a relieving line can be installed directly next
to the signal cable for current dissipation. The relieving line should have a crosssection of approximately 35 mm2.
l Analog signal lines must have double shielded cables, the inside shield must be
grounded at one end and the outside shield at both ends.
l Signal lines must be wired with an over-voltage protection element, that is
connected at the cable entrance to the building when possible or at the cabinet
as a minimum.
Observe the following: Guidelines for Grounding and Earthing for Systems between
Buildings, p. 108.
Recommended
for data transfer
between
buildings
144
Fiber optic cables are recommended for data transfer between buildings. This
creates no problems with loops between exposed conductive parts in the event of a
lightning strike.
Quantum Family
IV
Overview
Introduction
This section contains product specific guidelines, installation instructions and
information about grounding and EMC for the components of the Quantum product
family.
It contains the same information as the documentation provided with the products.
What's in this
Part?
This part contains the following chapters:
Chapter
Chapter Name
11
Quantum Family
Page
147
145
Quantum Family
146
Quantum Family
11
Overview
Introduction
This chapter contains product specific guidelines, installation instructions and
information abut grounding and EMC for the components of the Quantum product
family.
It contains the same information as the documentation provided with the products.
What's in this
Chapter?
This chapter contains the following topics:
Topic
Batteries as DC power supplies
Page
148
General Information
149
AC Power and Grounding Considerations
150
DC Power and Grounding Considerations
155
Closed System Installation
160
147
Quantum
Batteries as DC power supplies
Overview
148
Power Supplies usually provide the adequate protection from high and low
frequency RF noise because of filtered outputs. Batteries provide only good filtering
abilities against low frequency noise.
To protect battery powered networks, additional RFI filters are required such as:
l CURTIS F2800 RFI filters
l TRI-MAG, Inc. FL Series Filters or equivalent
Quantum
General Information
Overview
The required power and grounding configurations for AC powered and DC powered
systems are shown in the following illustrations. Also shown are power and
grounding configurations of AC and DC systems required for CE* compliance.
Note: Each backplane shown has its own ground connection; that is, a separate
wire returning to the main grounding point, rather than "daisy chaining" the grounds
between power supplies or mounting plates.
The main grounding point is the local common connection of the panel ground,
equipment ground, and earth grounding electrode.
CE Compliance
The CE mark indicates compliance with the European Directive on Electromagnetic
Compatibility (EMC) (89/336/EEC) and the Low Voltage Directive (73/23/EEC).
Note: In order to maintain CE compliance, the Quantum system must be installed
in accordance to these instructions.
Chassis
Grounding
A chassis ground wire is required for each backplane. The wire is connected
between one of four ground screws (located on the backplane) and the main ground
point of the power system. This wire should be green (or green with a yellow stripe)
and the AWG rating must be (at a minimum) sized to meet the fuse rating of the
supply circuit.
Power Supply
Grounding
On each power supply connector there is a ground connection. This connection
must be made for safety reasons. The preferred connection is between the power
supply connector ground terminal and one of the backplane ground screws. This
wire should be green (or green with a yellow stripe) and at a minimum the same
AWG rating as the power connections to the supply.
In backplanes with multiple power supplies, each supply should have a ground
connection between its input connector and the backplane ground screws.
Note: It is recommended that the power supply, feeding the I/O modules, is
grounded at the main ground point.
149
Quantum
Other Equipment
Grounding
Other equipment in the installation should not share the grounding conductor of the
system. Each piece of equipment should have its own grounding conductor
returning to the main grounding point from which the equipment power originates.
Systems with
Multiple Power
Feeds
In systems with multiple power feeds, the grounding should proceed in the same
manner as single feed systems. However, a zero volt potential difference must be
maintained between the equipment grounding conductors of the separate systems
to prevent current flow on communication cables.
AC Power and Grounding Considerations
AC Powered
Systems Figure
The following figure shows the AC powered systems.
PS
FUSE
GND
AC POWER
SOURCE
AC L
GROUND
SCREWS
EQUIPMENT
(CHASSIS)
GROUND
AC POWER
SOURCE
I/O
or
C
O
M
M
BACKPLANES
AC N*
PS
PANEL
GROUND
POINT
FUSE
I/O
or
C
O
M
M
AC N*
FUSE
AC POWER
SOURCE
AC L
C I/O I/O
P or or
U C C
O O
M M
M M
AC L
EQUIPMENT
(CHASSIS)
GROUND
GND
C I/O I/O
P or or
U C C
O O
M M
M M
I/O PS
or
C RED
O
M
M
GND
GROUND
SCREWS
AC N*
Note: *AC N should be earth grounded. If it is not earth grounded, it must be fused
(refer to local codes)
150
Quantum
The following figure shows a AC powered systems for CE compliance.
AC Powered
System for CE
Compliance
REDUNDANT/SUMMABLE
POWER SUPPLY
Detailed illustration will follow
FUSE
AC L
AC
POWER AC N
SOURCE
BROWN
BLUE
BACKPLANE
SHIELDED
CABLE
SHIELDED CABLE
AND FERRITE BEAD
LINE LOAD
BROWN
PS
BLUE
L
N
GREEN/YELLOW
GROUND
SCREWS
LINE
FILTER
C
P
U
I/O I/O I/O I/O
or or or or
C C
C
C
O O O O
M M M M
M M M M
PS
RED
L
N
SHIELDED
CABLE
PANEL
GROUND
SHIELDED CABLE
EARTH
GROUND
BROWN
BLUE
LINE LOAD
LINE
FILTER
BROWN
BLUE
CASE GND
CAUTION
European compliance
To maintain CE compliance with the European Directive on EMC (89/
336/EEC), the AC power supplies must be installed in accordance with
these instructions.
Failure to follow this precaution can result in injury or equipment
damage.
151
Quantum
CAUTION
Requirements compliance
For installations that must meet "Closed System" requirements, as
defined in EN 61131-2 (without relying upon an external enclosure),
connector models 140 XTS 00100 and 140 XTS 00500 are required.
Also, if an external Line Filter is used, it must be protected by a separate
enclosure which meets the "finger safe" requirements of IEC 529,
Class IP20.
Failure to follow this precaution can result in injury or equipment
damage.
152
Quantum
The following figure shows the details for the AC powered system for CE
compliance.
Detailed AC
Powered System
Figure
Quantum Backplane
140 XBP XXX 00
1
2
3
BACKPLANE
GND SCREWS
AC LINE
(BROWN)
4
BROWN
GND
LEAD
1
BROWN
3 4
AC NEUT
(BLUE)
6
Line Filter
GND
(GRN/YEL)
BLUE
SHIELD
PANEL
GROUND
EARTH
GROUND
BLUE
5
Shield
GND Lead
CASE TAB
GREEN/YELLOW*
(TO GROUND SCREW ON
QUANTUM BACKPLANE)
Line (Brown wire)
Neutral (Blue wire)
GND (Green/Yellow wire)
Note: Only one ground wire per backplane is required. In redundant and summable
systems, this lead is not connected for the additional line filter/power supply.
Note: For detailed wiring diagrams, refer to the part Power Supply Modules
153
Quantum
Part list
154
Table of the parts
Callout
Vendor or
equivilant
Part Number
Description
Instruction
1
OflexSeries 100
cy
35005
Line Cord
Terminate the
shield at panel
ground; the filter
end of the shield is
not terminated.
2
Stewart
Fairite
28 B 0686-200
2643665702
Ferrite Bead
Install next to the
filter and secure
with tie wraps at
both ends of the
ferrite bead.
3
Schaffner
FN670-3/06
Install next to the
Line Filter (fast on
power supply.
terminals)
Dimensions:
Length: 3.4" (85 mm)
Width: 2.2" (55 mm)
Height: 1.6" (40 mm)
Mounting Holes: 0.2 in
(5.3 mm) dia.,
3 in (75 MM) centerline
mounted.
Fast on terminals: 0.25 in
(6.4 mm)
4
NA
NA
Ground Braid
NA
Flat braid 0.5 in (134 mm)
with a maximum length of
4" (100 mm)
5
Oflex Series 35005
100cy
Shield Cable
The maximum length is
8.5" (215 mm)
Third lead (green/
yellow) is not used;
terminate the shield
at the power supply
ground terminal.
Quantum
DC Power and Grounding Considerations
24 VDC Powered
System Figure
The following figure shows a 24 VDC powered system.
PS
FUSE
24 V COM
FUSE
+
GND
EARTH GROUND
I/O I/O
or or
C C
O O
M M
M M
I/O
or
C
O
M
M
I/O
or
C
O
M
M
+24 VDC
BACKPLANES
24 V
−
C
P
U
24 V COM
PANEL
GROUND
POINT
EQUIPMENT
(CHASSIS)
GROUND
PS
GND
C
P
U
I/O I/O
or or
C C
O O
M M
M M
I/O PS
or RED
C
O
M
M
GND
GROUND
SCREWS
FUSE +24 VDC
24 V COM
Note: It is recommended to earth ground the 24 VDC power supply.
155
Quantum
24 VDC Powered
System for CE
Compliance
The following figure shows a 3 A, 24 VDC powered system for CE compliance.
See detailed figure below.
PS
Shielded Cable and
Ferrite Bead
24 VDC
Common
C
P
U
I/O
I/O
I/O
+24 VDC
GND
SHIELD
GROUND
SCREWS
EARTH GROUND
BACKPLANE
CAUTION
European compliance
To maintain CE compliance with the European Directive on
EMC (89/336/EEC) and the Low Voltage Directive (73/23/EEC), the
140 CPS 211 00, the 140 CRA 211 20, and the 140 CRA 212 20 must
be installed in accordance with these instructions.
Failure to follow this precaution can result in injury or equipment
damage.
156
Quantum
24 VDC Detailed
Figure
The following figure shows the detailed installation of a 3 A, 24 VDC powered
system for CE compliance.
BLUE
GREEN/
YELLOW
EARTH
GROUND
2
5 6
24 VDC
COM
QUANTUM BACKPLANE
140 XBP XXX 00
4
+24 VDC
1 2
1
BROWN
QUANTUM
BACKPLANE
GND SCREWS
GND
LEAD
GREEN/
YELLOW
SHIELD
GND
LEAD
Wire to the power supply
as follows:
24 Vdc COM (Blue wire)
+24 Vdc (Brown wire)
GND
Note: For detailed wiring diagrams, refer to the part Power Supply Modules
Parts List.
Callout
Vendor (or
equivalent)
Part Number
Description
Instruction
1
Offlex Series
100cy
35005
Line Cord
Terminate the shield at the
power supply ground
terminal
157
Quantum
125 VDC
Powered System
Figure
Callout
Vendor (or
equivalent)
Part Number
Description
Instruction
2
Sreward
Fairite
28 BO686-200
2643665702
Ferrite Bead
Install next to the filter and
secure with tie wraps at Both
ends of the ferrite bead.
The following figure shows a 125 VDC powered system for CE compliance.
See detailed figure below.
BACKPLANE
PS
SHIELDED CABLE AND
FERRITE BEAD
+125 VDC
125 VDC
COMMON
C
P
U
I/O
or
C
O
M
M
I/O
or
C
O
M
M
I/O
or
C
O
M
M
I/O
or
C
O
M
M
PS
RED
GND
SHIELD
GROUND
SCREWS
EARTH
GROUND
SHIELDED CABLE AND FERRITE BEAD
CAUTION
European compliance
To maintain CE compliance with the European Directive on
EMC (89/336/EEC) and the Low Voltage Directive (73/23/EEC), the
140 CPS 511 00 and the 140 CPS 524 00 must be installed in
accordance with these instructions.
Failure to follow this precaution can result in injury or equipment
damage.
158
Quantum
125 VDC Detailed
Figure
The following figure shows the detailed installation for the 125 VDC powered system
for CE compliance.
QUANTUM BACKPLANE
140 XBP XXX 00
1
GND
LEAD
4 5 6
BROWN
1 2 3
QUANTUM
BACKPLANE
GND SCREWS
GREEN/
YELLOW
+125 VDC
125 VDC COM
BLUE
GREEN/
YELLOW
SHIELD
GND LEAD
EARTH GROUND
2
Wire to the power supply as follows:
+125 VDC (Brown wire)
125 VDC COM (Blue wire)
GND
Note: For detailed wiring diagrams of all power supply modules, refer to the part
159
Quantum
Parts List.
Callout
Vendor (or
equivalent)
Part Number
Description
Instruction
1
Offlex Series
100cy
35005
Line Cord
Terminate the shield at the
power supply ground
terminal
2
Sreward
Fairite
28 BO686-200
2643665702
Ferrite Bead
Install next to the filter and
secure with tie wraps at Both
ends of the ferrite bead.
CAUTION
European compliance
To maintain CE compliance with the European Directive on
EMC (89/336/EEC) and the Low Voltage Directive (73/23/EEC), the
140 CPS 511 00 and the 140 CPS 524 00 must be installed in
accordance with these instructions.
Failure to follow this precaution can result in injury or equipment
damage.
Closed System Installation
Overview
160
For installations that must meet "Closed System" requirements, as defined in EN
61131-2 (without relying upon an external enclosure) in which an external Line Filter
is used, it must be protected by a separate enclosure which meets the "finger safe"
requirements of IEC 529, Class IP20.
Quantum
The following figure shows the detailed installation for the AC and DC powered
systems for CE closed system compliance.
AC/DC
Installation
Figure
QUANTUM BACKPLANE
140 XBP XXX 00
BACKPLANE
GND SCREWS
AC LINE
(BROWN)
STRAIN RELIEF
BUSHING
4
(WIRING DETAILS
FOR LINE FILTER
SHOWN ON NEXT
PAGE)
6
GND
(GRN/
YEL)
SHIELD
GND LEAD
SHIELD
PANEL
GROUND
EARTH
GROUND
1 2
AC NEUT
(BLUE)
GND
LEAD
STRAIN
RELIEF
BUSHING
PROTECTIVE COVER
FOR LINE FILTER
GREEN/YELLOW*
(TO GROUND SCREW ON
QUANTUM BACKPLANE)
**140 XTS 00 500
CONNECTOR REQUIRED
Wire to the power supply as follows:
.
Line (Brown wire)
Neutral (Blue wire)
GND (Green/Yellow wire)
Note: *Only one ground wire per backplane is required. In redundant and
summable systems, this lead is not connected for the additional line filter/power
supply
**Connectors 140 XTS 005 00 (for all power supplies) and 140 XTS 001 00 (for all
I/O modules) must be ordered separately.
161
Quantum
Note: For detailed wiring diagrams, refer to the part Power Supply Modules
Protective Cover
The protective cover must completely enclose the line filter. Approximate
dimensions for the cover are 12.5 cm by 7.5 cm. Wire entry/exit shall be through
strain relief bushings.
Line Filter
Connections
Figure
The following figure shows the wiring connections to the enclosed line filter.
Brown
Brown
Blue
Blue
Case tab
Protective Cover
162
Green/Yellow
(To ground screw on
Quantum backplane)
Ground wire for
metal box (Not
required for plastic box
Momentum Family
V
Overview
Introduction
This chapter contains product specific guidelines, installation instructions and
information about grounding and EMC for the components of the Momentum
product family.
It contains the same information as the documentation provided with the products.
What's in this
Part?
This part contains the following chapters:
Chapter
12
Chapter Name
Momentum Family
Page
165
163
Momentum Family
164
Momentum Family
12
Overview
Introduction
This chapter contains product specific guidelines, installation instructions and
information about grounding and EMC for the components of the Momentum
product family.
It contains the same information as the documentation provided with the products.
What's in this
Chapter?
This chapter contains the following topics:
Topic
Structuring Your Power Supply System
Page
166
Selecting Power Supplies
167
Single Power Supply Configuration
168
Protective Circuits for DC Actuators
170
Protective Circuits for AC Actuators
171
Suggested Component Values for AC and DC Actuators
172
Grounding Momentum Devices
172
Grounding DIN Rail Terminals and Cabinets
174
Grounding Analog I/O Lines
175
165
Momentum
Structuring Your Power Supply System
Overview
This section contains guidelines for planning and wiring your power supply system.
Use Separate
Power Supply for
Outputs
Operating voltage and input voltage can be derived from one power supply (PS). We
recommend that the output voltage be drawn from a separate power supply (e.g., 10
A or 25 A, referred to as PS1 and PS2).
A separate output voltage supply prevents interferences caused by switching
processes from affecting the voltage supply to the electronics. Where larger output
currents are involved, provide additional power supplies for the output voltage
(PS3, ...).
Use Star
Configuration
Each I/O base should be fed by the power supply in star configuration, i.e., separate
leads from the power supply to each module.
CAUTION
POTENTIAL FOR SHORT CIRCUITS AND/OR POWER-UP/POWERDOWN SPIKES
Provide external fuses on the operating voltage to protect the module.
Appropriate fuse values are shown in the wiring diagrams. An
unprotected module may be subject to short circuits and/or power-up/
power-down spikes.
Failure to follow this precaution can result in injury or equipment
damage.
Avoid Induction
Loops
Do not create any induction loops. (This can be caused by laying out the supply
conductors L+/M-, ... in pairs.) As a remedy use twisted-pair wiring.
Avoid Series
Connections
The series connections often found in automatic circuit breakers should be avoided,
since they increase the inductive component in the output-voltage leads.
PotentialIsolated Fieldbus
Islands
The potential relationships of the bus adapters are designed so that the individual I/
O stations form potential-isolated islands (e.g., by isolating the incoming remote bus
of InterBus). To decide whether potential balancing is necessary refer to the
installation guidelines of the used communication adapter.
166
Momentum
Selecting Power Supplies
Introduction
This section provides guidelines for selecting power supplies.
Using ThreePhase Bridges
Unfiltered three-phase bridges can be used in 24 VDC power supplies for the I/O
bases, the sensors, and the actuators. In view of the maximum permissible ripple of
5%, monitoring for phase failure is necessary. For single-phase rectification, the
24 VDC must be buffered to ensure conformance to the specifications in System
Specifications on page 595 (20...30V; max. ripple 5 %).
CAUTION
POTENTIAL FOR DANGEROUS VOLTAGE LEVELS
You must electrically isolate the AC-to-DC converter between the input
(primary) and output (secondary). Otherwise, dangerous voltage levels
can be propagated to the output if the AC-to-DC converter fails.
Failure to follow this precaution can result in injury or equipment
damage.
Provide Reserve
Capacity
Startup transients, extra long cables, and low cross-sectional efficiency can lead to
voltage supply breakdowns. You should therefore select power supplies with
enough reserve capacity and select the proper cable lengths and cross sections.
167
Momentum
Single Power Supply Configuration
Introduction
This section contains illustrations of a sample circuit layout, potential bundling and
potential isolation for a single power supply configuration.
Fusing in Circuit
Layout
Each of the following circuit branches must be fuse-protected (F in the figure below).
In the case of long lines, the circuit branch must be provided with a suppressor circuit
OVP 001/OVP 248. This protection selectively shuts off a circuit branch through the
associated fuse even if the diode is short-circuited.
Illustration
The following illustration shows a sample circuit layout for a single power supply
configuration.
F
I/O Base
F
I/O Base
24V
3/
F10
I/O Base
2.5 mm ² Cu
(14 AWG)
PS
-24 VDC
F
V1
0V
2.5 mm ² Cu
(14 AWG)
F
Automatic circuit breaker or fuse (see appropriate field wiring illustration in I/O base
description)
F10 Optional circuit breaker (with over-voltage protection)
PS Power Supply 24 VDC, max. 25 A
V1 Overvoltage protection circuit OVP 001, OVP 002
Fusing in Wiring
Illustrations
168
The fuses shown in the illustrations below must be selected on the basis of the type
and number of the sensors and actuators used.
Momentum
Potential
Bundling
In this example, the output voltage is drawn from a separate power supply.
24 V for internal logic and sensors
0V
ADI 340 00
Input
ADM 350 10
16 inputs, 16 out-
ADO 340 00
Output
24 V for actuators
0V
Potential
Isolation
In this example, the output voltage is drawn from a separate power supply
24 VU1 for internal logic and sensors
0 VU1
ADM 390 30
10 inputs, 8 out-
U2 Voltage for relays
0 VU2
169
Momentum
Protective Circuits for DC Actuators
Overview
This section discusses specific cases when inductive loads at output points require
additional protective circuits (directly on the actuator) and provides two examples or
protective circuitry.
Case 1
When there are contacted circuit elements (e.g. for safety interlocks) in the output
conductors.
Case 2
When the leads are very long.
Case 3
Where inductive actuators are operated via relay contacts of the I/O base. (To
extend contact life and for EMC considerations.)
Protective
Circuit Types
In all three cases, the protective circuit may be a clamping diode, a varistor or an RC
combination.
Example 1
An example of a protective circuit for inductive DC actuators is illustrated below:
-
+
+
V1
K1
Out
Load
-
K1 Contact, e.g., for safety interlocks
V1 Clamping diode as the protective circuit
170
Momentum
Example 2
Another example of a protective circuit for inductive DC actuators is illustrated
below:
-
+
+
V2
Out
Load
V2 Clamping diode as the protective circuit
See Suggested Component Values for AC and DC Actuators, p. 172.
Protective Circuits for AC Actuators
Overview
To reduce noise potentials and for EMC considerations you may need to equip the
inductive actuators with varistors or noise suppressors, e.g., anti-interference
capacitors, at the point of interference.
Example
An example of a protective circuit for inductive AC actuators is illustrated below:
N
R
L
+
C
Out
Load ( RL )
L, N Phase (L1, L2, L3) and Reference Conductor
RC RC Combination as the Protective Circuit (rated per manufacturer's specifications
RL Inductance Load
See Suggested Component Values for AC and DC Actuators, p. 172.
171
Momentum
Suggested Component Values for AC and DC Actuators
Suggested
Values Only
The clamping diode forward current rating must be equal to or greater than load
current. Diode PIV rating must be three or four times greater than supply voltage at
24 VDC and 8 ... 10 times greater than supply voltage at 110 VAC. The unpolarized
(AC) snubb
Values may be:
Load Inductance
Capacitance
25 ... 70 mH
0.50 microF
70 ... 180 mH
25 microF
180 mH
10 microF
Snubber resistors may be 1 ... 3 Ohms, 2 W. Resistor values should be increased
up to 47 Ohms/5 W for R L exceeding 100 Ohms.
Grounding Momentum Devices
Overview
This section describes how to provide two types of grounding for assembled
Momentum devices:
l Functional earth (FE), used to discharge high frequency disturbances,
guaranteeing proper EMC behavior
l Protective earth (PE), used for protection against personal injuries according to
IEC and VDE.
Grounding
Momentum
Devices
Momentum devices consist of an I/O base assembled with a Communications
Adapter or a Processor Adapter and possibly an Option Adapter. The PE of the
adapters is electrically connected with the PE of the I/O base; you do not have to
provide any further grounding of the adapter.
Grounding
Guidelines
Cable
Specifications
172
Follow these guidelines:
l Be sure you establish good ground contacts.
l Connect the grounding screw to protective earth (PE) for AC and DC modules.
When you are using ground cable up to 10 cm (4 in) long, its diameter should be at
least 12 AWG (or 2.5 mm 2). When longer cables are used, larger cable diameters
are required, as shown in the following illustration
Momentum
The illustration below illustrates properly grounding modules and tracks.
1
to M of the power supply N1, N2, ...
Grounding
Scheme
> 8 AWG or 6 mm2
< 100 cm Length
> 12 AWG or 2.5 mm2
< 10 cm Length
2
short cable length
>8 AWG or 6 mm2
3
1
Grounding clamp, such as EDS 000
2
Cable Grounding Rail (CER 001), an optional component for grounding lines close to PE/
FE rail
3
PE/FE rail in the cabinet or PE/FE screw in terminal cabinet
Note: The lower DIN rail shows a Cable Grounding Rail (CER 001), an optional
component for grounding analog lines. For a procedure for grounding analog I/O
lines, see Grounding Analog I/O Lines, p. 175.
173
Momentum
Grounding DIN Rail Terminals and Cabinets
Overview
This section shows how to ground DIN rail terminals and cabinets.
Illustration
The following illustration shows how to ground DIN rail terminals and cabinets:
1
1
5
2
3
4
*
XY
FE
PE
2
> 6 AWG or 16 mm
1
DIN rail for connecting the Momentum device and its accessories
2
Reference conductor system or rail (solid copper or connected terminals)
3
Grounding bar in the cabinet
4
Next cabinet
5
Grounding screw (PE/FE) in cabinet
FE Functional earth
PE Protective earth
XY Protective earth choke
*
174
Conductor cross section depends on the load of the system
Momentum
Grounding Analog I/O Lines
Overview
Analog wires must be grounded directly when entering the cabinet. You may use
commercial cleats or clamps or an analog cable grounding rail. This section
describes both approaches.
Principle
High frequency interference can only be discharged via big surfaces and short cable
lengths.
Guidelines
Follow these wiring guidelines:
l Use shielded, twisted-pair cabling
l Expose the shielding on one side (for instance, at the console exit)
l Make sure the track is properly grounded (see Grounding Momentum Devices,
p. 172
Grounding of the bus cable is determined by the bus adapter used. Look for details
in your bus adapter manual.
Using Cleats or
Clamps
Cleats or clamps can be mounted directly on the ground rail (PE/FE rail) in the
cabinet, as shown in the illustration below. Be sure the cleats or clamps make
proper contact.
175
Momentum
176
Premium Family
VI
Overview
Introduction
This chapter contains product specific guidelines, installation instructions and
information about grounding and EMC for the components of the Premium product
family.
It contains the same information as the documentation provided with the products.
What's in this
Part?
This part contains the following chapters:
Chapter
Chapter Name
Page
13
Standards Conformity and EMC Characteristics
179
14
Basic elements: Backplane RKY, power supply PSY
189
15
Power Supply for the Process and AS-i SUP
203
16
Discrete I/O Modules DEY/DSY
219
17
Safety Modules PAY
231
18
Counter Modules CTY
237
19
Axis Control Modules CAY
245
20
Stepper Motor Control Modules CFY
247
21
Electronic Cam Module CCY 1128
251
22
Analog Modules AEY/ASY
263
23
Weighing Module ISPY100/101
265
177
Premium Family
178
Standards Conformity and EMC
Characteristics
13
Introduction
Introduction
This section provides an overview of the standards that Premium Hardware
Products conform to, and also includes EMC standards. It also includes exact
information about the products disturbance immunity and emitted disturbance.
What's in this
Chapter?
This chapter contains the following topics:
Topic
Page
Standards and Certification
180
Operating conditions and environmental conditions to be avoided
181
179
Standards Conformity and EMC Characteristics
Standards and Certification
General
180
Premium TSX/PMX/PCX PLCs have been developed to conform to the principal
national and international standards for industrial electronic PLC equipment.
l Programmable PLCs: specific requirements: functional characteristics,
resistance, safety etc.
IEC 61131-2, CSA 22.2 N° 142, UL 508
l Merchant navy requirements of the major international organisations:
ABS, BV, DNV, GL, LROS, RINA, RRS, CCS etc.
l Adhering to European Directives:
Low Voltage: 73/23/EEC amendment 93/68/EEC
Electromagnetic Compatibility: 89/336/EEC amendments 92/31/EEC and 93/68/
EEC
l Electric qualities and self-extinguishability of insulating materials: UL 746C, UL
94
l Danger Zones Cl1 Div2 CSA 22.2 N° 213
"THIS EQUIPMENT IS SUITABLE FOR USE IN CLASS I, DIVISION 2,
GROUPS A, B, C AND D OR NON-HAZARDOUS LOCATIONS ONLY"
WARNING: "EXPLOSION HAZARD - DO NOT DISCONNECT WHILE CIRCUIT
IS LIVE UNLESS AREA IS KNOWN TO BE NON-HAZARDOUS"
Standards Conformity and EMC Characteristics
Operating conditions and environmental conditions to be avoided
Operating
temperature/
hygrometry/
altitude
Power supply
voltages
Voltage
Data table:
Ambient temperature when
operative
0°C to +60°C (IEC 1131-2 = +5°C to +55°C)
Relative humidity
10% to 95% (without condensation)
Altitude
0 to 2000 meters
Data table:
nominal
24 VDC
48 VDC
100 to 240VAC
100...120/200...240 VAC
limit
19 to 30 VDC 19...60VDC (1)
90 to 264 VAC
90 to 140/190 to 264VAC
nominal
-
-
50/60 Hz
50/60 Hz
limit
-
-
47/63 Hz
47/63 Hz
duration
≤ 1 µs
≤ 1 µs
≤ 1/2 period
≤ 1/2 period
repetition
≥1s
≥1s
≥1s
≥1s
Harmonic rate
-
-
10%
10%
Residual ripple
included
5%
5%
-
-
Frequency
Brown-outs
(1) Possible up to 34 VDC, limited to 1 hour every 24 hours.
For PSY 1610 and PSY 3610 power supplies, and when using relay output modules,
this scope is reduced to 21.6V...26.4V.
181
Standards Conformity and EMC Characteristics
Human and
material safety
Data table:
Test Designation
Norms
Levels
Dielectric rigidity and
Isolation resistance *
IEC 61131-2
UL 508
CSA 22-2 N°142
IEC 60950
24 - 48 V Power supply
100 -220 V Power supply
< 48V Discrete I/Os
> 48V Discrete I/Os
> 10 MΩ
Maintaining ground
connections*
IEC 61131-2
UL 508
CSA 22-2 N°142
< 0.1 Ω / 30 A / 2 min
Leakage Current *
CSA 22-2 N°142
IEC 60950
< 3.5 mA fixed device
Enclosures for protection * IEC 61131-2
CSA 22-2 N°142
IEC 60950
IP 20
Impact Resistance
Drop / 1.3 m / 500 g Sphere
CSA 22-2 N°142
IEC 60950
1500 Vrms
2000 Vrms
500 Vrms
2000 Vrms
Legend
*: Tests required by EC directives
Note: The devices must be installed and wired according to the directions in the
DG KBL• manual.
182
Standards Conformity and EMC Characteristics
Resistance of
devices to power
supply L.F.
turbulence
Data table:
Test Designation
Norms
Levels
Voltage and frequency
Variation *
EN 50082-1
Un 15% / Nf 5%
Un 20% / Nf 10%
Continuous voltage
variation *
EN 50082-1
0.85 Un - 1.2 Un
+ 5% ripple maximum
Harmonic 3 *
IEC 61131-2
10% Un
0° / 5 min - 180° / 5 min
Momentary
Interruptions *
IEC 61131-2
AC
DC
Voltage peaks and
troughs *
IEC 61131-2
Un-0-Un; Un / 60s 3 cycles separated by 10 s
Un-0-Un; Un / 5s 3 cycles separated by 1 to 5 s
Un-0.9-Un; Un / 60s 3 cycles separated by 1 to 5 s
30 min x 2
5sx2
30 + 30 min
10 ms
1 ms
Legend
Un: Nominal Voltage Nf: Nominal Frequency Ud: Power-on detection level
*: Tests required by EC directives
Note: The devices must be installed and wired according to the directions in the
DG KBL• manual.
183
Standards Conformity and EMC Characteristics
Resistance to
H.F. turbulence
Data table:
Test Designation
Norms
Levels
Amortized oscillatory
wave *
IEC 61131-2
IEC 61000-4-12
AC / DC
24 V Discrete I/Os
1 kV SM
1 kV SM
Fast transients (bursts) EN 50082-1
*
IEC 61000-4-4
AC / DC Power Supply
48 V > Discrete I/Os
other ports
2 kV WM / CM
2 kV CM
1 kV CM
Hybrid shockwave
AC / DC Power Supply
AC Discrete I/Os
DC Discrete I/Os
Shielded Cable
2 kV WM / 1 kV SM
2 kV WM / 1 kV SM
2 kV WM / 0.5 kV SM
1 kV CM
IEC 61000-4-5
Electrostatic Discharge IEC 61131-2
*
IEC 61000-4-2
6 kV contact
8 kV air
Electromagnetic Field * EN 50082-2
IEC 61000-4-3
10 V/m, 80MHz - 2 GHz
Sinusoidal modulation amplitude 80% / 1kHz
Conduit Turbulence *
10 V 0.15 MHz - 80 MHz
Sinusoidal modulation amplitude 80% / 1kHz
EN 50082-2
IEC 61000-4-6
Legend
SM: Serial mode CM: Common Mode WM: Wire Mode
*: Tests required by EC directives
Note: The devices must be installed and wired according to the directions in the
DG KBL• manual.
184
Standards Conformity and EMC Characteristics
Electromagnetic
Emissions
Data table:
Test Designation
Norms
Levels
Conduction Limits *
EN55022/55011
EN50081-2
Class A
150 kHz - 500 kHz quasi-peak 79 dB mV
average 66 dB mV
500 kHz -30 kHz quasi-peak 73 dB mV
average 60 dB mV
Emission Limits *(1)
EN55022/55011
EN50081-2
Class A
d = 10 m
30 kHz -230 kHz quasi-peak 30 dB mV/m
230 kHz -1 kHz quasi-peak 37 dB mV/m
Legend
(1) This test is carried out outside the casing, with the devices secured to a metallic
grill and wired as shown in the DG KBL• Manual.
*: Tests required by EC directives
Note: The devices must be installed and wired according to the directions in the
DG KBL• manual.
185
Standards Conformity and EMC Characteristics
Resistance to
climatic variation
Data table:
Test Designation
Norms
Levels
Dry heat
IEC60068-2-2 Bd
60°C / 16h (E.O)
40°C / 16h (E.F)
Cold
IEC60068-2-1 Ad
0°C / 16h
Continuous humid heat IEC60068-2-30 Ca
60°C / 93% Hr /96h (E.O)
40°C / 93% Hr /96h (E.F)
Cyclical humid heat
IEC60068-2-30 Db
(55°C E.O / 40°C E.F); - 25°C / 93-95% Hr
2 cycles: 12 o' clock - 12h o' clock
Cyclical temperature
variations
IEC60068-2-14 Nb
0°C; -60°C / 5 Cycles: 6 o'clock-6 o'clock
(E.O.)
0°C; -40°C / 5 Cycles: 6 o'clock-6 o'clock
(E.F)
Temperature Rise
IEC61131-2
UL508
CSA22-2 N°142
Ambient temperature: 60°C
Legend
E.O: Device open E.F: Device closed Hr: Relative Humidity
Resistance to
mechanical
constraints
Data table:
Test Designation
Standards
Levels
Sinusoidal vibrations
IEC60068-2-6 Fc
3 Hz - 100 Hz / 1 mm amplitude / 0.7 Gn
Endurance: rf / 90 min / axis (Q limit) < 10
3 Hz - 150 Hz / 1.5 mm / 2 Gn
Endurance: 10 cycles (1 octave / min)
Half-sinus shocks
IEC60068-2-27 Ea
15 Gn x 11 ms
Legend
rf: Resonance Frequency Q: Amplification Coefficient
186
3 shocks / direct. / axis
Standards Conformity and EMC Characteristics
Resistance to
climatic variation
Resistance to
mechanical
constraints
Data table:
Test Designation
Standards
Levels
Dry heat whilst inoperative
IEC60068-2-2 Bb
70°C / 96h
Cold whilst inoperative
IEC60068-2-1 Ab
-25°C / 96h
Humid heat whilst inoperative
IEC60068-2-30 dB
60°C; - 25°C / 93-95% Hr
2 cycles: 12 o' clock - 12h o'
clock
Thermal shocks whilst inoperative
IEC60068-2-14 Na
-25°C; -70°C / 2 Cycles: 3
o'clock - 3 o'clock
Test Designation
Standards
Levels
Flat free drop
IEC60068-2-32 Ed
10 cm / 2 drops
Free drop from controlled position
IEC60068-2-31 Ec
30° or 10 cm / 2 drops
Random free drop (conditioned
material)
IEC60068-2-32
Method 1
1 m / 5 drops
Data table:
187
Standards Conformity and EMC Characteristics
188
Basic elements: Backplane RKY,
power supply PSY
14
Overview
Introduction
This section contains guidelines and information for the configuration and
installation of the basic elements of the Premium hardware with regard to grounding
and EMC.
What's in this
Chapter?
This chapter contains the following topics:
Topic
Connection of the ground to a RKY rack
Page
190
How to mount processor modules
191
Precautions to be taken when replacing a PCX 57 processor
193
Rules for connecting PSY supply modules
193
Connecting alternating current power supply modules
196
Connecting direct current power supply modules from an alternating current
network
198
189
Basic elements
Connection of the ground to a RKY rack
Grounding racks
Functional grounding of the racks is guaranteed by the back, which is made of metal.
This means that the PLCs can be guaranteed to conform to environmental norms;
assuming, however, that the racks are fixed to a metal support that is correctly
connected to ground. The different racks which can make up a P57 PLC station
must be mounted either on the same support or on different supports, as long as the
latter are correctly interlinked.
For people’s safety, in every case, each rack’s grounding terminal must be linked to
the protective ground.
For this, use a green/yellow wire of with a minimum section of 2.5 mm 2 and of the
shortest length possible.
Illustration:
support
connected
to the
ground
yellow/green wire linked to the ground
Note: The PLC’s internal 0V is linked to the ground connection. The ground
connection itself being linked to ground.
Maximum lightning moment on the ground connection screw: 2.0 N.m.
190
Basic elements
How to mount processor modules
Introduction
Mounting and removing processor modules is identical to mounting and removing
other modules apart from the fact that it must not be done when power is
switched on.
Note: when extracting/inserting modules with the power on, the terminal block or
HE10 connector must be disconnected. You must also take care to shut off the
sensor/preactuator supply if this is over 48V.
Installing a
processor
module onto a
rack
Carry out the following steps:
Step
Action
1
Place the pins at the back of the module into
the centering holes on the lower part of the
rack (number 1, see diagram 1).
2
Swivel the module to bring it into contact with
the rack (number 2).
3
Fix the processor module to the rack by
tightening the screw on the upper part of the
module (number 3).
Illustration
Note: the mounting of processor modules is identical to the mounting of other
modules.
Note: Maximum tightening torque: 2.0N.m.
191
Basic elements
CAUTION
Install with power off
A processor module must always be mounted with the rack power
supply switched off.
Failure to follow this precaution can result in injury or equipment
damage.
Grounding
modules
Processor modules are grounded using metal plates at the rear of the module. When
the module is in place, these metal plates are in contact with the metal of the rack.
This ensures the link with the ground connection.
Illustration
Ground connection contacts
192
Basic elements
Precautions to be taken when replacing a PCX 57 processor
Important
CAUTION
Replacing a processor
If the PCX 57 processor is being replaced by another processor which
is not blank (i.e. the processor has already been programmed and
contains an application), you must cut the power to all of the PLC
station’s control units.
Before restoring power to the control units, check that the processor
contains the required application.
Failure to follow this precaution can result in injury or equipment
damage.
Rules for connecting PSY supply modules
General points
The PSY ••• power supply modules on each rack are equipped with a nonremovable terminal block, protected by a flap, which is used to connect the power
supply, the alarm relay, the protection ground and, for alternating current supplies,
the supply of the 24 VDC sensors.
This screw terminal block is equipped with captive clamp screws which can connect
a maximum of 2 wires with a cross-sectional area of 1.5mm 2 with wire end ferrules,
or one wire with a cross-sectional area of 2.5mm
screw terminal: 0.8N.m).
2
(maximum tightening torque on
The wires come out vertically towards the bottom. These wires can be kept in place
with a cable-clip.
193
Basic elements
Illustration
This diagram shows the screw terminal block:
Supply
24V
sensors
Alarm relay
Alarm relay
Network ~
110-220V
24V
network (1)
Protection
ground
PE
Protection
ground
PE
Alternating current supply
TSX PSY 2600/5500/8500
Direct current supply
TSX PSY 1610/3610/5520
(1) 24...48VAC for the PSY 5520 supply module.
CAUTION
Positioning the voltage selector
For the power supply modules PSY 5500/8500, position the voltage
selector according to the voltage power used (110 or 220 VAC).
Failure to follow this precaution can result in injury or equipment
damage.
Provide a protection device and switchgear upstream of the PLC station.
When selecting protection devices, the user should take into account the signaling
currents which are defined in the characteristics tables for each supply module.
194
Basic elements
Note: As direct current supply modules PSY 1610/2610/5520 have a strong
signaling current, it is not advisable to use them on direct current networks which
protect flood-back current limits.
When a power supply module is connected to a direct current network, it is
mandatory to limit the length of the supply cable in order to prevent transmission
loss.
l PSY 1610 supply module:
l length limited to 30 meters (60 meters there and back) with copper wires and
a 2.5mm2 cross-section,
l length limited to 20 meters (40 meters there and back) with copper wires and
a 1.5mm2 cross-section.
l PSY 3610 and PSY 5520 supply modules:
l length limited to 15 meters (30 meters there and back) with copper wires and
a 2.5mm2 cross-section,
l length limited to 10 meters (20 meters there and back) with copper wires and
a 1.5mm2 cross-section.
Warning
Linking several PLCs supplied by a permissible direct current network not
connected to ground.
The 0V and physical ground are linked internally in the PLCs, in the network cabling
accessories and in some control consoles.
For specific applications which use a "floating" installation, special measures should
be taken with connections. These depend on the method used for installation.
In this case, it is mandatory to use insulated direct current power supplies. Please
contact us when you are defining the electrical installation.
195
Basic elements
Connecting alternating current power supply modules
Connecting a
single-rack PLC
station
Illustration:
Alternating network 100-240 V
Supply control
Pre-actuators
Sensor supply
for sensors on the rack (2)
TSX PSY ..00
Q: general section switch,
KM: circuit contactor-breaker,
(1) insulating connector bar for finding grounding faults
(2) available current:
l 0.6 A with a PSY 2600 power supply module,
l 0.8 A with a PSY 5500 power supply module,
l 1.6 A with a PSY 8500 power supply module,
Note: Protective fuses: alternating current power supply modules PSY 2600/
5500/8500 are fitted during manufacture with a protective fuse. This fuse, in series
with the L input, is located inside the module and cannot be accessed.
196
Basic elements
Connecting a
PLC station
made up of
several racks
Illustration:
Alternating network 100-240 V
Supply control
pre-actuators
Sensor supply
for sensors on the rack (2)
TSX PSY ..00
Supply control
pre-actuators
Sensor supply
for sensors on the rack (2)
TSX PSY ..00
Note: If there are several PLC stations supplied by the same network, the
principles of connection are identical.
Q: general section switch,
KM: circuit contactor-breaker,
(1) insulating connector bar for finding grounding faults
(2) available current:
l 0.6 A with a PSY 2600 power supply module,
l 0.8 A with a PSY 5500 power supply module,
l 1.6 A with a PSY 8500 power supply module,
Note: Protective fuses: alternating current power supply modules PSY 2600/
5500/8500 are fitted during manufacture with a protective fuse. This fuse, in series
with the L input, is located inside the module and cannot be accessed.
197
Basic elements
Connecting direct current power supply modules from an alternating current
network
Non-insulated
power supply
modules PSY
1610/3610
Connecting a single-rack PLC station with a ground-referenced network:
Alternating network 100-240 V
Supply control
pre-actuators
TSX PSY ..10
Supply for sensors/
pre-actuators
Q: General section switch,
KM: Circuit contactor-breaker,
(1): External shunt provided with the power supply module,
(2): Insulating connector bar for finding grounding faults. In this case, it is necessary
to switch off the supply in order to disconnect the network from the ground,
(3): Optional use of a process power supply module,
(4): Protective fuse, (4 A, with time-delay) only necessary with the PSY 3610 power
supply module.
The PSY 1610 power supply module is fitted during manufacture with a protective
fuse located under the module and in series on the 24V input (3.5 A, 5x20 time-delay
fuse).
198
Basic elements
Connecting a multi-rack PLC station with a ground-referenced network:
Alternating network 100-240 V
Supply control
pre-actuators
TSX PSY ..10
Supply
sensors/
pre-actuators
Supply control
pre-actuators
TSX PSY ..10
Q: General section switch,
KM: Circuit contactor-breaker,
(1): External shunt provided with the power supply module,
(2): Insulating connector bar for finding grounding faults. In this case, it is necessary
to switch off the supply in order to disconnect the network from the ground,
(3): Optional use of a process power supply module,
(4): Protective fuse, (4 A, with time-delay) only necessary with the PSY 3610 power
supply module.
The PSY 1610 power supply module is fitted during manufacture with a protective
fuse located under the module and in series on the 24V input (3.5 A, 5x20 time-delay
fuse).
Note: If there are several PLC stations supplied by the same network, the
principles of connection are identical.
199
Basic elements
PSY 5520
isolated power
supply module
Connecting a single-rack PLC station with a ground-referenced network:
Alternating network 100-240 V
Supply control
pre-actuators
TSX PSY 5520
Supply for sensors/
pre-actuators
Q: General section switch,
KM: Circuit contactor-breaker,
(1): Insulating connector bar for finding grounding faults,
(2): Optional use of a process power supply.
Note: Protective fuse: the PSY 5520 power supply modules are fitted during
manufacture with a protective fuse. This fuse, in series with the 24/48V input, is
located inside the module and cannot be accessed.
200
Basic elements
Connecting a multi-rack PLC station with a ground-referenced network:
Alternating network 100-240 V
Supply control
pre-actuators
TSX PSY 5520
Supply for sensors/
pre-actuators
Supply control
pre-actuators
TSX PSY 5520
Q: General section switch,
KM: Circuit contactor-breaker,
(1): Insulating connector bar for finding grounding faults,
(2): Optional use of a process power supply.
Note: Protective fuse: the PSY 5520 power supply modules are fitted during
manufacture with a protective fuse. This fuse, in series with the 24/48V input, is
located inside the module and cannot be accessed.
Note: If there are several PLC stations supplied by the same network, the
principles of connection are identical.
201
Basic elements
202
Power Supply for the Process and
AS-i SUP
15
Overview
Introduction
This section contains guidelines and information for the configuration and
installation of the power supply for the Process and AS-i-Bus with regard to
grounding and EMC.
What's in this
Chapter?
This chapter contains the following topics:
Topic
Page
Connection of SUP 1011/1021 power supplies
204
Connection of SUP 1051 power supplies
206
Connection of SUP 1101 power supplies
208
Connection of SUP A02 power supply modules
211
Connecting SUP A05 supply modules
213
General precautions
217
203
Power Supply
Connection of SUP 1011/1021 power supplies
Illustration
Connection diagram:
Parallelization
Normal connection
Module 1
Module 2
Fu=External safety fuse
on phase (Fu): 250 V 4A time delay.
(1) 100...240VAC on TSX SUP 1011
100...120/200..240VAC on TSX SUP 1021
(2) 125 VDC, only on TSX SUP 1011.
204
Power Supply
Connection rules
Primary:if the module is supplied with a 100/240V AC power supply, it is necessary
to observe wiring requirements for the phase and neutral when connecting the
module. However, if the module is powered by a 125 VDC supply, it is not necessary
to respect the polarities.
l an operating voltage ≥ 600 V AC with a cross-section of 1.5 mm2 for connection
to the mains,
DANGER
Safety of personnel
To ensure the safety of personnel, the ground terminal of the module
must be connected to the protective earth using a green/yellow wire.
Failure to follow this precaution will result in death, serious injury,
or equipment damage.
The power supply terminal is protected by a flap which allows access to the wiring
terminals. The wires come vertically out of the power supply at its base. These wires
can be kept in place with a cable-clip.
Secondary: to comply with isolation requirements for a 24 V SELV isolated voltage,
the following wiring is used:
l an operating voltage ≥ 300 V AC with a cross-section of 2.5 mm2 for the 24 V
outputs and the ground.
205
Power Supply
Connection of SUP 1051 power supplies
Illustration
Connection diagram:
Normal connection
Parallelization
Module 1
Fu=External safety fuse on phase
(Fu): 250V 4A time delay
206
Module 2
Power Supply
Connection rules
Primary: observe the rules concerning phase and neutral when wiring.
l an operating voltage ≥ 600 VAC with a cross-section of 1.5 mm2 for connection
to the mains,
DANGER
Safety of personnel
To ensure the safety of personnel, the ground terminal of the module
must be connected to the protective earth using a green/yellow wire.
Failure to follow this precaution will result in death, serious injury,
or equipment damage.
The power supply terminal is protected by a flap which allows access to the wiring
terminals. The wires come vertically out of the power supply at its base. These wires
can be kept in place with a cable-clip.
Secondary: to comply with isolation requirements for a 24 V SELV isolated voltage,
the following wiring is used:
l an operating voltage ≥ 300 V AC with a cross-section of 2.5 mm2 for the 24 V
outputs and the ground.
207
Power Supply
Connection of SUP 1101 power supplies
Illustration 1
Normal connection diagram:
output terminal
input terminal
AC network
connection
200..240V
208
AC network
connection
100..120V
24 VDC output
connection.
Power Supply
Illustration 2
Parallel connection diagram (parallelization):
input terminals
output terminals
Module 1
Module 2
(1) Connection for a 100...120 VAC power supply.
(2) External safety fuse on phase (Fu): 250 V 6.3A time delay.
209
Power Supply
Connection rules
Primary: Observe the rules concerning phase and neutral when wiring.
l an operating voltage ≥ 600 V AC with a cross-section of 1.5mm2 or 2.5mm2 for
connection to the mains,
DANGER
Safety of personnel
To ensure the safety of personnel, the ground terminal of the module
must be connected to the protective earth using a green/yellow wire.
Failure to follow this precaution will result in death, serious injury,
or equipment damage.
The power supply terminal is protected by a flap which allows access to the wiring
terminals. The wires come vertically out of the power supply at its base. These wires
can be kept in place with a cable-clip.
Secondary: To comply with isolation requirements for a 24 V SELV isolated voltage,
the following wiring is used:
l an operating voltage ≥ 300 V AC with a cross-section of 2.5 mm2 for the 24 V
outputs and the ground.
l Wire the two 24V terminals in parallel, or distribute the load over the two 24V
outputs when the total current to be supplied is greater than 5A.
210
Power Supply
Connection of SUP A02 power supply modules
Illustration
Connection diagram:
(1) Shielded AS-i cable
screen if environment is
disturbed.
Fu=External safety fuse on
phase (Fu): 250 V 4A time
delay.
Connection
synoptic
The SUP A02 power supply module is designed to supply the AS-i bus, and the
connected slaves (30 VDC/2.4A).
AS-i Master
211
Power Supply
Connection rules
Primary: observe the rules concerning phase and neutral when wiring.
DANGER
Safety of personnel
To ensure the safety of personnel, the ground terminal of the module
must be connected to the protective earth using a green/yellow wire.
Failure to follow this precaution will result in death, serious injury,
or equipment damage.
The power supply terminal is protected by a flap which allows access to the wiring
terminals. The wires come vertically out of the power supply at its base. These wires
can be kept in place with a cable-clip.
To comply with isolation requirements for a 24 V SELV isolated voltage, the
following wiring is used:
l an operating voltage ≥ 600 VAC with a cross-section of 1.5 mm2 for connection
to the mains,
l an operating voltage ≥ 300 VAC with a cross-section of 2.5 mm2 for the 24 V
outputs and the ground.
It is necessary to use a shielded cable for the AS-i bus only in cases where the
installation is subject to very high levels of disturbance in terms of EMC (Electro
Magnetic Compatibility).
212
Power Supply
Connecting SUP A05 supply modules
Illustration
Connection diagram:
Input terminal
Output terminal
(1)
(3)
Connection to
alternating network
200..240 V
Connection to an
alternating network
100...120 V
Direct output connection 24V
and 30 V AS-i
(1) Connection if supply is from 100120V alternating current network.
(2) External protection fuse on phase (Fu): 6.3A time delay 250 V.
(3) Shielded AS-i cable screen in case of disrupted surroundings.
213
Power Supply
Connection
overview
The SUP A05 supply module is designed to supply the AS-i bus, including the slaves
which are connected to it (30V/5A output). It also has an auxiliary supply (24 VDC/
7A) for sensors/actuators which consume large amounts of current. For this, a black
AS-i ribbon cable is used.
Principle diagram:
AS-i master
214
Power Supply
Rules of
connection
Primary: observe the rules concerning phase and neutral when wiring.
l an operating voltage ≥ 600 V AC with a cross-section of 1.5mm2 or 2.5mm2 for
connection to the mains,
DANGER
Safety of personnel
For personnel safety, the module ground terminal must be connected to
the protective ground with a green/yellow wire.
Failure to follow this precaution will result in death, serious injury,
or equipment damage.
The "AC power supply network" and "24V and 30 V DC output" AS-i terminals are
protected by a flap allowing access to the wiring terminals. The wires come vertically
out of the power supply at its base. These wires can be kept in place with a cableclip.
Secondary: to comply with isolation requirements for a 24 V SELV isolated voltage,
the following wiring is used:
l an operating voltage ≥ 300 V AC with a cross-section of 2.5mm2 for the 24 V
outputs and the ground,
l connect the two 24V terminals in parallel, or distribute the load over the two 24V
outputs when the total current to be provided is greater than 5A.
Using a shielded cable for the AS-i bus is only necessary if the installation is overly
disrupted in terms of EMC (Electro Magnetic Compatibility).
Given the large current that this supply module provides, its position on the bus is
very important.
If the supply module is placed at one of the ends of the bus, it will provide a nominal
current (e.g. 5A) for the whole bus. The fall in voltage at the end of the bus is
therefore proportional to the 5A.
If it is positioned in the middle of the bus, the voltage drop at the ends is proportional
to only 2.5A, assuming that the consumption for both sections of the bus is the
same.
215
Power Supply
Supply
AS-i
2.5 A
2.5 A
If there is no slave which consumes large amounts of power, it would be better to
place the supply module in the middle of the installation. Conversely, if the
installation has one or several large power consumers, it would be wise to place the
supply module close to them.
Note: Where there are large power consumer actuators (contactor, solenoid coils
etc.) the SUP A05 supply module can provide the auxiliary 24 VDC, insulated from
the AS-i line.
216
Power Supply
General precautions
Introduction
While installing the yellow AS-i cable, it is essential to place it in a cable track which
is separate from the power cables. It is also advisable to place it flat and not twisted.
This will help make the two AS-i cable wires as symmetrical as possible.
Installing the AS-i cable on a surface connected to the electric potential of the
machine (for example, the housing) complies with the requirements of the EMC
(Electro Magnetic Compatibility) directive.
The end of the cable, or the ends in the case of a bus with a star-formation , must
be protected either:
l by connecting it (them) to a T-derivation,
l by not allowing them to come out of their last connection point.
Important
It is important to distribute power effectively on the AS-i bus, so that each device on
the bus is supplied with sufficient voltage to enable it to operate properly. To do this,
certain rules must be followed.
Rule 1
Select the caliber of the supply module adapted to the total consumption of the ASi segment. Available calibers are 2.4A (SUP A02) and 5A (SUP A05).
A caliber of 2.4A is generally sufficient based on an average consumption of 65mA
per slave for a segment made up of a maximum of 31 slaves.
217
Power Supply
Rule 2
To minimize the effect of voltage falls and reduce the cost of the cable, you must
determine the best position of the supply module on the bus, as well as the minimum
size of cable appropriate for distributing power.
The voltage fall between the master and the last slave on the bus must not exceed
3V. For that purpose, the table below gives the essential points for selecting the
cross-sectional measurement of the AS-i cable.
Table of characteristics:
Cross-section
measurement of AS-i
cable
0.75 mm2
Linear resistance
52 milli Ohms/meter 27 milli Ohms/
meter
16 milli Ohms/
meter
Voltage fall for 1A over 100
meters
5.2V
1.6V
1.5 mm2
2.7V
2.5 mm2
The cable which can be used for most applications is the cable with a cross-section
of 1.5 mm 2. This is the standard AS-i bus model (the cable is offered in the
SCHNEIDER catalog).
Smaller cables can be used when sensors consume very little power.
Note: The maximum length of all the segments making up the AS-i bus without a
relay is 100 meters. The lengths of cables which link a slave to a passive
distribution box must be taken into account.
218
Discrete I/O Modules DEY/DSY
16
Overview
Introduction
This section contains guidelines and information for the configuration and
installation of the Premium hardware discrete I/O modules with regard to grounding
and EMC.
What's in this
Chapter?
This chapter contains the following topics:
Topic
Page
Choice of direct current power supply for sensors and pre-actuators
associated with Discrete I/O modules.
220
Precautions and general rules for wiring with Discrete I/O modules
221
Means of connecting Discrete I/O modules: connecting HE10 connector
modules
225
Means of connecting Discrete I/O modules: connecting screw terminal block
modules
227
Ways of connecting discrete I/O modules: connecting modules to TELEFAST
interfaces using an HE10 connector
228
219
Discrete I/O Modules
Choice of direct current power supply for sensors and pre-actuators associated
with Discrete I/O modules.
At a Glance
The following is a presentation of precautions for choosing sensors and preactuators associated with Discrete I/O modules.
External direct
current power
supplies
When using an external 24 VDC direct current power supply, it is advised to use
either:
l regulated power supplies;
l non-regulated power supplies but with the following filtering:
l 1000 microF/A with full-wave single phase rectification and 500 microF/A with
tri-phase rectification;
l 5% maximum peak to peak ripple;
l maximum voltage variation: -20% to +25% of the nominal voltage (including
ripple).
Note: Rectified power supplies with no filtering are prohibited.
Ni-Cad battery
power supplies
220
This type of power supply can be used to power sensors and pre-actuators and all
associated I/Os that have a normal operating voltage of 30 VDC maximum.
While being charged, this type of battery can reach, for a duration of one hour, a
voltage of 34 VDC. For this reason, all I/O modules with an operating voltage of
24 VDC can withstand this voltage (34 VDC) for up to one hour every 24 hours. This
type of operation entails the following restrictions:
l at 34 VDC, the maximum current withstood by the outputs must under no
circumstances exceed the maximum current defined for a voltage of 30 VDC;
l temperature downgrading imposing the following restrictions:
l 80% of I/Os at 1 at up to 30°C;
l 50% of I/Os at 1 to 60°C.
Discrete I/O Modules
Precautions and general rules for wiring with Discrete I/O modules
At a Glance
The Discrete I/Os feature protective measures which ensure a high resistance to
industrial environmental conditions. Certain rules, shown below, must nevertheless
be respected.
External power
supplies for
sensors and preactuators.
External sensor and pre-actuator power supplies associated with Discrete I/O
modules must be protected against this short circuits and overloads by quick-blow
fuses.
For HE10 connector Discrete I/O modules, the sensor/pre-actuator power supply
must be linked to each connector, except in the event where the corresponding
channels are not in use and are not assigned to any task.
Note: if an I/O module with screw block terminals or HE10 connector is present in
the PLC, the sensor/pre-actuator voltage must be connected to the module;
otherwise an "external supply" error is signaled and the I/O LED comes on.
In the event that the 24 VDC installation is not carried out according to SELV
(safety extra low voltage) standards, the 24 VDC power supplies must have the 0V
linked to mechanical ground, which is in turn linked to the ground as close as
possible to the power supply. This restriction is necessary for personnel safety in
the event of a power phase coming into contact with the 24 VDC supply.
221
Discrete I/O Modules
Inputs
Recommendations for use concerning Discrete I/O module inputs are as follows:
l for fast input modules (DEY 16 FK/DMY 28FK/DMY 28RFK):
l in the event that 24 VDC direct current inputs are used, it is recommended to
adapt the filtering time to the required function;
l in order for bounces not to be taken into account upon closure of contacts, it
is not advisable to use sensors with mechanical contact outputs if the filtering
time is reduced to under 3 ms;
l for faster operation, the use of direct current inputs and sensors is
recommended, as alternating current inputs have a much higher response
time.
l for 24 VDC inputs and line coupling with an alternating current network:
l operation can be disturbed if the coupling between cables relaying an
alternating current and cables relaying signals intended for direct current
inputs is too large. This is illustrated in the following circuit diagram. When the
Principle diagram
Module
Input %I
Output %Q
The alternating current neutral
connection is directly or indirectly
linked to the ground.
input contact is open, an alternating current exceeding the cable's interference
capacities may generate a current in the input which might cause it to be set
to 1.
l the line capacity values that must not be exceeded, for a 240 VCA/50 Hz line
coupling, are given in the summary table at the end of this paragraph. For a
coupling with a different voltage, the following formula can be applied:
Acceptable capacity = (Capacity at 240 VAC x 240) / line voltage
l for 24 to 240 VAC inputs and line coupling:
222
Discrete I/O Modules
l In this case, when the line that controls the input is open, the current passes
according to the coupling capacity of the cable (see circuit diagram below).
Principle diagram
Module
Input %I
l the line capacity values that must not be exceeded are given in the summary
table at the end of this paragraph.
The summary table below shows the acceptable line capacity values.
Module
Maximum coupling capacity
24 VDC inputs
DEY 32 / DEY
64D2K
25 nF (1)
DEY 16D2
45 nF (1)
DEY 16FK / DMY
10 nF (1) (2)
28FK / DMY 28RFK 30 nF (1) (3)
60 nF (1) (4)
24 to 240 VAC inputs
DEY 16A2
50 nF
DEY 16A3
60 nF
DEY 16A4
70 nF
DEY 16A5
85 nF
Legend
(1)
Max. admissible coupling capacity with 240 VAC / 50 Hz line
(2)
Filtering = 0.1 ms
(3)
Filtering = 3.5 ms
(4)
Filtering = 7.5 ms
223
Discrete I/O Modules
Outputs
Recommendations for use concerning Discrete I/O module outputs are as follows:
l it is recommended to segment starts, protecting each one with a quick-blow fuse,
if currents are high;
l wires of a sufficient diameter should be used to avoid drops in voltage and
overheating.
Cable routing
Precautions for use to be taken concerning the wiring system are as follows:
l in order to reduce the number of alternating couplings, power circuit cables
(power supplies, power switches, etc.) must be separated from input cables
(sensors) and output cables (pre-actuators) both inside and outside the
equipment.
l outside the equipment, cables leading to inputs / outputs should be placed in
covers that make them easily distinguishable from those containing wires
relaying high energy levels. They should also be placed preferably in separate
grounded metal cableways. These various cables must be routed at least
100 mm apart.
224
Discrete I/O Modules
Means of connecting Discrete I/O modules: connecting HE10 connector
modules
At a Glance
HE10 connector modules are connected to sensors, pre-actuators or terminal
blocks using a pre-formed cable designed to allow the smooth and direct transition
of module inputs/outputs from wire to wire.
Pre-formed cable
CDP 301 / 501
The 3 meter long CDP 301 or 5 meter long CDP 501 pre-formed cables are made
up of:
l a molded HE10 connector at one end with 20 protruding sheathed wires with a
cross-section of 0.34 mm2;
l free wires at the other end, differentiated by a color code complying with DIN
47100.
Note: A nylon thread built into the cable allows easy-stripping of the sheath.
Note: HE10 connectors must be engaged or disengaged with sensor and preactuator voltage switched off.
225
Discrete I/O Modules
The diagram below shows the connection of the pre-formed cable to the module.
Module
Pre-formed cable
Top
white
brown
green
yellow
gray
pink
blue
red
Correspondence
between the color of
wires and the HE10
connector pin number
black
violet
gray-pink
red-blue
white-green
brown-green
white-yellow
yellow-brown
white-gray
gray-brown
white-pink
pink-brown
TSX CDP 301 / 501
Bottom
Note: The maximum torque setting for tightening CDP • cable connector screws is
0.5 N.m
226
Discrete I/O Modules
Means of connecting Discrete I/O modules: connecting screw terminal block
modules
At a Glance
Discrete I/O module terminal blocks feature an automatic code transfer device
activated on first use. This allows fitting errors to be avoided when replacing a
module. This coding guarantees electrical compatibility by module type.
Description of
the screw
terminal block
Every terminal block can receive bare wires or wires with terminations or spade
terminals.
The capacity of each terminal is:
l minimum: 1 x 0.2 mm2 wire (AWG 24) without termination;
l maximum: 1 x 2 mm2 wire without termination or 1 x 1.5 mm2 with termination.
Illustration of the termination and the spade terminal.
(1) 5.5 mm maximum.
The maximum capacity of the terminal block is 16 x 1 mm2 wires (AWG) + 4 x 1.5
mm2 wires (AWG).
Screw clamps come with slots for the following types of screwdriver:
l Pozidriv No. 1;
l 5 mm diameter flat head.
Screw connection terminal blocks feature captive screws. On the supplied blocks,
these screws are not tightened.
Note: The maximum torque setting for tightening connection terminal block screws
is 0.8 N.m
Note: Screw terminal blocks must be engaged or disengaged with sensor and preactuator voltage switched off.
227
Discrete I/O Modules
The diagram below shows the method for opening the screw terminal block door.
Ways of connecting discrete I/O modules: connecting modules to TELEFAST
interfaces using an HE10 connector
At a Glance
Connecting discrete input/output modules to TELEFAST interfaces for connecting
and adapting fast wiring HE10 connectors, is done with the aid of:
l a 28 gage multi-stranded sheathed cable (0.08 mm2);
l a 22 gage connection cable (0.34 mm 2).
CDP 102/202/302
connection cable
The 28 gage connection cable (0.08 mm 2) comes in three different lengths:
l 3 ft 3.4 in length: CDP 102;
l 6 ft 6.8 in length: CDP 202;
l 9 ft 10.2 in length: CDP 302.
This cable is made up of 2 HE10 connectors and a multi-stranded sheathed ribbon
cable, where each wire has a cross-section area of 0.08 mm 2.
Given the small area of each of the wires, you are advised to only use it for low
current inputs or outputs (< 100 mA per input or output).
228
Discrete I/O Modules
CDP 053/103/203/
303 /503
connection cable
The 22 gage connection cable (0.34 mm2) comes in five different lengths:
l 1 ft 7.7 in length: CDP 053;
l 3 ft 3.4 in length: CDP 103;
l 6 ft 6.8 in length: CDP 203;
l 9 ft 10.2 in length: CDP 303;
l 16 ft 5 in length: CDP 503.
This cable is made up of 2 sheathed HE10 connectors, and a cable with a crosssection of 0.34 mm 2, which can take higher currents (> 500 mA).
Illustration
The illustration below shows the two types of connection to the TELEFAST interface
via multi-strand cable or other cable.
Module
TSX CDP cable •02
TSX CDP cable ••3
TELEFAST 2 ABE-7H•••••
Note: Check the consistency between the rating of the fuse on board the
TELEFAST 2 and the fuse which is to be used on the inputs/outputs (see
Connecting modules).
229
Discrete I/O Modules
230
Safety Modules PAY
17
Overview
Introduction
This section contains guidelines and information for the configuration and
installation of the Premium hardware safety modules with regard to grounding and
EMC.
What's in this
Chapter?
This chapter contains the following topics:
Topic
Page
General description of safety modules
232
Wiring precautions
233
Cable dimensions and lengths
234
231
Safety Modules
General description of safety modules
General
The TSX PAY 2•2 safety modules and their accessories TSX CPP 301/•02 and
TELEFAST 2 ABE-7CPA13 are used to interrupt one or several category 0 safety
or emergency stop control circuits (safety components) in complete safety. The
entire safety system is compliant with European standards EN 418 for emergency
stops and EN 60204-1 for safety circuits.
These modules also comply with safety requirements regarding the electrical
monitoring of position switches activated by protection devices.
The TSX PAY 2•2 safety modules provide:
l A safety system designed to control the emergency stop circuits of machines in
complete safety. The modules are equipped with a wired logic safety block for
monitoring emergency stops.
l Full diagnostics of the safety system readable from the status of the position
switches and push-buttons of the emergency stop input sequence, the
reactivation input, the feedback loop, the control of both output circuits, and the
safety system power supply status. All this information is sent to the PLC’s CPU
in the form of 28-bit Discrete inputs.
Note: The PLC has no effect on the safety modules, and the safety system section
is connected to an external power supply.
232
Safety Modules
Wiring precautions
General
The safety system must be wired in accordance with EN60204-1. This section gives
a description of the rules for 'wiring and mechanically protecting cables.
The 'entire safety system, the ES PBs or PSs, TSX PAY 2•2 modules, protection
fuses and auxiliary relays are incorporated in housings with an IP54 minimum
protection index as per EN954-1.
Grounding
The module has no grounding terminal on its front panel. Depending on the
TSX CPP •02 cable being used, the 0 VDC can be grounded (cf. EN60204-1)
directly via the TELEFAST ABE-CPA13.
Note: The TSX CPP 301 cable has no ground connection.
Protection of
safety system
Errors within the safety modules can be propagated to the 'outside of the module,
particularly to the 'external supply in use: short circuits within the module can cause
a supply voltage avalanche 'or a supply malfunction if it is 'not protected. This is why
a 1 A (gL) quick-blow fuse ' is placed in the control section of the relays, given that
maximum consumption is 200 mA.
Note: This fuse, called F1, is an active element of the safety system.
The module also contains a 'current limiting device set to 750 mA in order to detect
inter-channel short circuits on the ES PBs or PSs. The external supply is protected'
in the event of this happening, and an error is indicated on the safety system.
In order to guarantee the safety function, it is compulsory 'to use the following:
l On input
l double contact ES PBs or PSs,
l the NF contacts of the guided-contact auxiliary relays in the feedback loop,
l On output
l two or four guided-contact auxiliary relays,
l a 4 A gL output protection fuse F2,
l On the external 'module supply: a 1 A (gL) protection fuse F1.
233
Safety Modules
Protection of
safety outputs
Output voltages can reach ' 230 VAC or 127 VDC.
Outputs are not protected inside the 'module, though GMOV-type (for a continual
load), or RC cell-type (for an alternating load) protection is applied directly to the
terminals of the load in use. These protective measures must be adapted to the load.
The 'use of guided-contact auxiliary relays and the feedback loop wiring then make
it possible to detect a safety output short circuit.
A 4 A (gL) quick-blow fuse is located in the auxiliary supply circuit 'to protect the
module’s safety relay contacts and the connected loads: this fuse is identical to that
used in PREVENTA modules.
The fuse F2, located on the safety outputs, provides protection against short circuits
and overloads. This protection avoids the melting of the safety relay contacts in
TSX PAY 2•2 modules.
Cable dimensions and lengths
General points
The length of safety system wires can cause a drop in supply voltage related to the
current circulating. This voltage drop is due to sum of the currents circulating on the
0 VDC feedback path of the electrical circuit. It is usual practice to double or triple
the 0 VDC wires.
In order to ensure the correct operation of the safety system (reactivation of relays)
and a correct reading of diagnostic information, it is important that the voltage
measured between terminals A1 and A2 be greater than 19.2 V.
Cross-section of
TELEFAST
cables
Each TELEFAST ABE-7CPA13 terminal accepts bare wires or ones fitted with
terminations, or spade or eye terminals.
The capacity of each terminal is:
l minimum: 1 x 0.28 mm2 wire without termination,
l maximum: 2 x 1 mm2 wires or 1 x 1.5 mm2 wire with termination.
The maximum cross-section dimensions for wires on the terminal block are:
1 x 2.5 mm 2 wire without termination.
234
Safety Modules
Calculation of
cable length
The resistance of each safety system ((+) channel and (-) channel) must not exceed
75 Ohms. The maximum resistance of the channel between an ES PB or PS and the
corresponding input of the module must be ≤ 6 Ω.
Given the length and cross-section of the cable, its resistance can be calculated as
l
R = ρ ⋅ ---S
follows:
Equation parameter
Parameter
Meaning
R
Cable resistance in Ohms
ρ
Resistivity: 1.78 x 10-8 Ω.m for copper
l
Cable length in m
S
Cross-section in m2
It is possible to wire the system so as to allow a greater distance between the ES
PBs or PSs and the module:
Standard wiring:
O121
O12
O122/131
O13
O132/141
O14
PAY
O142/151
O15
O152/161
O232
235
Safety Modules
Optimized length wiring:
O121
O12
O122/131
O13
O132/141
O14
PAY
O142/151
O15
O152/161
O232
: Length to be taken into account for calculation of the resistance.
236
Counter Modules CTY
18
Overview
Introduction
This section contains guidelines and information for the configuration and
installation of the Premium hardware counter modules with regard to grounding and
EMC.
What's in this
Chapter?
This chapter contains the following topics:
Topic
Process for connecting encoder count sensors
Page
238
General rules for implementation
239
Connecting the encoder supply
241
Wiring precautions
242
237
Counter Modules
Process for connecting encoder count sensors
Illustration
The CTY 4A module wiring is as follows. For a CTY 2A or CTY 2C module, only the
elements related to channels 0 and 1 should be connected.
Encoders
Encoders
Channel 0
Channel 1
Description of
the different
connection
elements
Channel 2
Channel 0
Channel 0
Channel 3
Channel 1
Channel 1
1 Process for connecting the encoder to the standard 15-pin SUB-D connector,
located on the CTY 2A / 4A / 2C module. Given the various encoder types, it is your
responsibility to carry out this connection, which consists of:
l a connector for linking to the encoder (determined by the connector on the
encoder in use; normally a female 12-pin DIN connector),
l a standard male 15-pin SUB-D connector, to connect to the female 15-pin SUBD connector on the CTY 2A/4A/2C module. This connector is available under
reference CAP S15,
l a cable:
l with twisted pairs (gauge 26) and shielding for an incremental encoder with
standard RS 422 line transmitter outputs or an absolute encoder,
l multi-conductor (gauge 24) with shielding for an incremental encoder with
Totem Pole outputs.
The type of cable shielding should be "braid and foil". The cables should be
completely supported to ensure the "braid and foil" is connected to the ground
connection of each connector.
Connection of the cable to the two connectors can vary according to the type of
encoder supply (5 VDC or 10…30 VDC) and the type of outputs (RS 422, Totem
Pole). By way of an example, certain types of connection are described in the
following pages.
238
Counter Modules
General rules for implementation
Installation
Connecting or disconnecting the standard 15 pin SUB-D connectors of the CTY 2A/
4A/ 2C modules to/from the encoder and sensor supplies present is not
recommended as this may damage the encoder. Some encoders cannot withstand
sudden and simultaneous signal and supply power-ups or outages.
General wiring
instructions
Wire sections
Use wires of a satisfactory section to avoid drops in voltage (mainly with 5 V) and
overheating.
Example of falls in voltage for encoders supplied with 5 V with a cable length of
100 meters:
Section of the wire
Encoder consumption
50 mA
100 mA
150 mA
200 mA
0.08 mm (gauge 28)
1.1 V
2.2 V
3.3 V
4.4 V
0.12 mm 2 (gauge 26)
-
1.4 V
-
-
-
0.8 V
-
-
0.25 V
0.5 V
0.75 V
1V
0.17 V
0.34 V
0.51 V
0.68 V
0.09 V
0.17 V
0.24 V
0.34 V
2
0.22
mm 2
2
(gauge 24)
0.34 mm (gauge 22)
0.5
1
mm2
mm 2
Connection cable
All cables carrying the sensor supply (encoders, proximity sensor etc.) and the
counting signals must:
l be at a distance from high voltage cables,
l be shielded with the shielding , which is linked to the protective ground
connection on both the PLC and encoder side,
l never carry signals other than counting signals and supplies relating to counting
sensors.
The connection cable between the module and encoder should be as short as
possible to avoid creating loops, as the circuit capacities can interfere with
operation.
Note: If necessary, direct the flow of the signal in the same cable as the supplies.
Cables with twisted pairs should preferably be used for this.
239
Counter Modules
Encoder and
auxiliary sensor
supply
Encoder supply
This must:
l be reserved exclusively for supplying the encoder to avoid parasitic pulses which
could interfere with the encoders, whose electronics are sensitive,
l be placed as close to the TELEFAST 2 base as possible to reduce drops in
voltage and coupling with other cables,
l be protected against short circuits and overloads by fast blow fuses,
l work well independently to avoid micro-power outages.
Auxiliary sensor supply
Refer to the general regulations for implementing discrete modules.
Note: The – 0 VDC polarity of the auxiliary encoder and sensor supplies should be
grounded as near to the supplies as possible.
The shielding of the cables carrying the voltages should be grounded.
Software
implementation
240
Software implementation and the language objects assigned to the different
counting functions are described in the "counting application" manual.
Counter Modules
Connecting the encoder supply
Diagram of the
principle
This diagram illustrates the connection of the encoder supply:
24 VDC supply connection
auxiliary input
sensors
TELEFAST 2
ABE-7H16R20
TSX CDP053 / 503 cable
Suppl
y.
Suppl
y.
Cable length:
Cable
Length
CDP 053
0.5 m
CDP 103
1m
CDP 203
2m
CDP 303
3m
CDP 503
5m
Note: The maximum length of the wire between the supply outputs and the
connection points on the TELEFAST should be less than 0.5 m.
Only one supply is required if the encoders on the two channels are of the same
type.
241
Counter Modules
Fuses
This module integrates several basic protection systems against wiring errors and
accidental short circuits on the cable:
l polarity inversions of the supplies,
l inversion of 5 V supplies <--> 10/30 V,
l 10/30 V short circuit on the CLOCK signal of the serial link.
The module cannot tolerate them for very long time, it should therefore have very
fast blow fuses. The fuses should therefore be "rapid" and of 1A caliber maximum.
Supplies should have a limitation current, such that the blow of the fuse can be
correctly executed.
Wiring precautions
General
242
The I0, I1 and I3 inputs are rapid inputs, which should be connected to the sensor
using either a twisted wire if it is a dry contact, or using shielded cables if it is a 2 or
3-wire proximity sensor.
The module integrates basic protection against short circuits or voltage inversions.
However, the module cannot remain operational for long with an error. You must
therefore ensure that the fuses in series with the supply carry out their protective
function. These are 1A maximum non-delay fuses, the supply energy must be
sufficient to ensure their fusion.
Counter Modules
Important note:
wiring of Q0
static outputs
The actuator connected to the Q0 output has its shared point at 0 V of the supply. If
for any reason (poor contact or accidental unplugging) there is a 0 V outage of the
output amplifier supply, when the 0 V of the actuators remains connected to the 0 V
supply, there may be enough mA output current from the amplifier to keep lowpower actuators locked.
Illustration:
+ + - -
C
C
C
C
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
1
2
3
4
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
+ + - -
IO
I1
I2
Q0
IO
I1
I2
204 104 205 105 206 106 112 312 208 108 209 109 210 110
+
+
+
+
RI
Connection via
TELEFAST
+
Q0
114 314
+
RI
This kind of connection provides the most guarantees, on condition that the shared
actuators are connected to the bar for shared points 200 to 215 (jumper wire in
position 1-2). In this case there can be no outage of the shared module without an
outage of the shared actuators.
243
Counter Modules
Connection
using strips
This kind of connection must be carried out with the highest care and attention. It is
recommended that you take special care in wiring this cable, for example using
cable markers on screw terminals. It may be necessary to double the connections
in order to ensure permanent contacts. When the actuator supply is a long distance
away from the modules and close to the shared actuators, there may be an
accidental break in the link between the latter and the 0 V or modules terminal
Illustration:
Critical wire
If there is a break of the supply section between A and B, there is a risk that the RL
actuators may not remain operational. You must, if possible, double connections of
0 V supply to the modules.
Using CDP 301/501 strips:
TSX CDP 301/501 strip
white-pink
white-gray
white-green
white-yellow
gray-brown
pink-brown
terminal block connection
244
Axis Control Modules CAY
19
General precautions for wiring
General
The supplies to sensors and actuators must be protected against overloading or
excess voltage by non-delay fuses.
When wiring, use wires of a satisfactory size to avoid on-line drops in voltage and
overheating,
Keep sensor and actuator cables away from any source of radiation resulting from
high-power electric circuit switches.
All cables which link the incremental or absolute encoders must be shielded. The
shielding should be good quality and linked to the protective ground connection on
the side of the module and the side of the encoder. Continuity must be ensured
throughout connections. Do not introduce any other signals than those of the
encoders in the cable.
For reasons of performance, the auxiliary inputs of the module have a short
response time. You must therefore make sure that the supply autonomy of these
inputs is sufficient to ensure the module continues to operate correctly in the event
of short power breaks. It is recommended that you use regulated supplies to ensure
more reliable response times from the actuators and sensors. The 0 V supply must
be linked to the protective ground connection as near to the supply output as
possible.
245
Axis Control Modules
246
Stepper Motor Control Modules
CFY
20
Overview
Introduction
This section contains guidelines and information for the configuration and
installation of the Premium hardware stepper motor control modules with regard to
grounding and EMC.
What's in this
Chapter?
This chapter contains the following topics:
Topic
Page
General precautions for wiring
248
Wiring precautions
248
247
Stepper Motor Control Modules
General precautions for wiring
General
The power supply to sensors and actuators must be protected against overload or
overvoltage by fast-blow fuses.
l when wiring use wires of sufficient size to avoid on-line voltage falls and
overheating,
l keep sensor and actuator cables away from any source of radiation resulting from
high-power electric circuit switching,
l all cables connecting the translators must be shielded, the shielding must be
good quality and connected to the protective ground both for the module and the
translator. Continuity must be ensured throughout connections. Do not transmit
any other signals in the cable than those for the translators.
For reasons of performance the auxiliary inputs of the module have a short response
time. You must therefore make sure that there is enough self-sufficient supply to
these inputs to ensure the module continues to operate correctly in the event of a
short power break. It is recommended that you use a regulated supply to ensure
more reliable response times from the actuators and sensors. The 0 V supply must
be connected to the protective ground nearest to the supply module output.
Wiring precautions
General
248
To ensure the best performance, inputs I0 to I5 are rapid inputs. If the actuator is a
dry contact, the inputs must be connected by a twisted pair, or by a shielded cable
if the sensor is a two or three-wire proximity detector.
The module includes as standard basic protection against short circuits or voltage
inversions. However, the module cannot remain operational for long with an error.
You must therefore ensure that the fuses in series with the supply carry out their
protective function. These are 1A maximum fast-blow fuses, the supply energy must
be sufficient to ensure their fusion.
Stepper Motor Control Modules
Important note:
wiring of Q0
static outputs
The actuator connected to the Q0 brake output has its shared pin connected to
supply 0 V. If for any reason there is a 0 V outage of the output amplifier supply (e.g.
poor contact or accidental unplugging), when the 0 V of the actuators remains
connected to the 0 V supply, there may be enough mA output current from the
amplifier to keep low-power actuators triggered.
Illustration:
+ + - -
C
C
C
C
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
1
2
3
4
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
+ + - -
IO
204
+
104
I1
205
+
105
I2
206
+
106
Q0
112
208
312
RI
Connection via
TELEFAST
IO
+
108
I1
209
+
109
I2
210
+
110
Q0
114
314
RI
This kind of connection is the most guaranteed, on the condition that the shared
actuators are connected to the 200 to 215 shared points strip (jumper wire in position
1-2). In this case there can be no outage of the shared module without an outage of
the shared actuators.
249
Stepper Motor Control Modules
Connection
using a CDP 301 /
501 pre-wired
strand
This kind of connection must be carried out with the greatest care and attention. It is
recommended that you take special care in wiring this cable, for example using the
cable ferules on screw terminals. It may be necessary to double the connections in
order to ensure permanent contacts. When the actuator supply is a long distance
away from the modules and close to the shared actuators, there may be an
accidental break of the link between the latter and the 0 V terminal of the module(s).
Illustration:
TSX CFY 11/21
Supplying
actuators
Critical wire
If there is a break of the supply section between A and B, there is a risk that the RL
actuators may not remain operational. You must, if possible, double connections of
0 V supply to the modules.
Connection using a CDP 301 / 501 pre-wired strand:
TSX CFY 11/21
HE10
white-pink
17
white-gray
19
13
15
white-green
24 V
white-yellow
RL
0V
RL
18
20
gray-brown
0VDC
pink-brown
0VDC
user connection terminal block
250
Electronic Cam Module CCY 1128
21
Overview
Introduction
This section contains guidelines and information for the configuration and
installation of the Premium hardware electronic cam module CCY 1128 with regard
to grounding and EMC.
What's in this
Chapter?
This chapter contains the following topics:
Topic
Page
Installation precautions for the CCY 1128
252
General wiring instructions
253
Selecting and protecting auxiliary power supplies
254
Choice of encoders for the CCY 1128
255
Connecting the encoder supply to the CCY 1128
257
Wiring rules and precautions specific to the TELEFAST
259
251
Electronic Cam Module
Installation precautions for the CCY 1128
Installation
In order to guarantee good working order, it is necessary to take certain precautions
during its installation and removal, when plugging and unplugging the connectors on
the front panel of the module, and when adjusting its fixing screws and the
SUB D 15-pin connector.
Installing and
removing the
module
The module can be installed or removed without cutting the supply to the rack. The
design of the module allows this action to be carried out with the power on in order
to ensure the availability of the device.
Plugging and
unplugging the
connectors on
the front panel of
the module
It is not recommended that you plug in or unplug the connectors located at the front
panel of the module when the sensor/pre-sensor supply is switched on.
Reasons:
l the encoders will not tolerate a simultaneous start-up or outage of the signals and
supplies.
l The track outputs can become damaged if they are in state 1 and connected to
an inductive supply
Adjusting the
screws and
locking the HE10
connectors in
place
In order to ensure good electrical contact between the devices and by doing so
create effective resistance to electrostatic and electromagnetic interference:
l the fixing screws on the module and the SUB D 15-pin connector must be
correctly screwed in.
l tightening on the module’s fixing screw: 2.0 N.m
l tightening on the SUB D 15-pin connector’s fixing screw: 0.5 N.m
l The HE10 connectors must be correctly locked.
252
Electronic Cam Module
General wiring instructions
Introduction
In order to guarantee that the automatism operates correctly, it is necessary to
respect some basic rules.
Section of wires
used
Must be of sufficient size to avoid on-line voltage falls and overheating.
Cable path.
The encoder connector cables, the other sensors and the pre-actuators must be
kept away from any source of radiation resulting from high-power electric circuit
switches and which could cause malfunctions.
Encoder signal
connector cables
The module/encoder connector cables must adhere to the following rules:
l They must be shielded using a high quality shielding,
l they must only carry related signals to the encoder,
l the cable shielding must be linked to the protective ground connection both at the
module and the encoder,
l the grounding must be continuous throughout the connection.
253
Electronic Cam Module
Selecting and protecting auxiliary power supplies
Introduction
Type of power
supply
Encoders, sensors and pre-actuators associated with the module require auxiliary
power supplies (5VDC and/or 24VDC).
Only use regulated power supplies to:
l ensure optimum reliable response time for sensors and pre-actuators,
l increase the reliability of devices by minimum heating of module I/O circuits.
These power supplies must be independent enough (> 10ms) to override micropower outages and ensure the module continues to run effectively.
Protecting power
supplies
The power supplies for encoders, other sensors and pre-actuators MUST be
protected from overloads and short-circuits by appropriately calibered fast-blow
fuses.
Connection of
the 0V supply to
the protective
ground:
The 0V supply must be connected to the protective ground nearest to the supply
module output.
General rules for
installing the
encoder power
supply module
l this must be used only for supplying the encoder,
l it must be independent enough to override micro-power outages (> 10ms).
l it must be placed as close as possible to the CCY 1128 module to reduce circuit
254
capacities to the maximum.
Electronic Cam Module
Choice of encoders for the CCY 1128
Introduction
The CCY 1128 module inputs are able to receive signals from the following
encoders:
l incremental,
l absolute with SSI serial outputs,
l absolute with parallel outputs. This last type requires the use of a specific
interface TELEFAST ABE-7CPA11.
The user can choose from these encoder types according to the requirements.
Encoder output
interface
The table below summarizes the main characteristics of the output interface for the
encoder types normally used.
Encoder supply
Type
of encoder
Supply
voltage
Output
voltage
Types of interface
Incremental
5 VDC
5 VDC differential
Outputs with line transmitters to
RS 422 standard, with 2 outputs
per signal A+/A-, B+/B-, Z+/Z-
10...30 VDC
10...30 VDC
Totem Pole outputs with one
output per signal A, B, Z
Absolute
with SSI
outputs
10...30 VDC
5 VDC differential
Output with line transmitters to RS
422 standard for the data signal
(Data SSI)
RS 422 compatible input for the
clock signal (CLK SSI).
Absolute
with parallel
outputs
5 VDC or
10...30 VDC
5 VDC or 10...30
VDC
Parallel outputs. Require the use
of the Telefast ABE-7CPA11
interface to transform parallel
output signals into serial signals.
The design of the module allows an encoder supply of:
l 5 VDC
l 24 VDC, standardized voltage in the 10…30 VDC format.
The choice of supply voltage is dependent on the encoder supply voltage.
255
Electronic Cam Module
5 VDC encoder
supply
For encoders with a 5 VDC supply, voltage falls must be taken into account. These
are dependent upon:
l the length of the cable between the module and the encoder (double length),
l the section of wire,
l the encoder consumption.
The acceptable voltage fall for the encoder is generally 10% of the nominal voltage.
The table below gives the on-line voltage fall, according to the section of the wire,
for a 100 meter length of wire with a given encoder consumption.
Section of wire
Voltage fall for a 100 meter length of wire with an encoder
consumption of:
50 mA
100 mA
150 mA
200 mA
0.22 mm = gauge 24
0.4 V
-
-
-
0.34 mm = gauge 22
0.25 V
0.5 V
-
-
0.5 mm
0.17 V
0.34 V
0.51 V
-
1 mm
0.09 V
0.17 V
0.24 V
0.34 V
CAUTION
Recommendation for a 5 VDC encoder supply voltage
It is dangerous to raise the supply voltage of the encoder to compensate
for an on-line voltage fall. After a break in the supply, there is a risk of
an overvoltage at the module inputs.
Failure to follow this precaution can result in injury or equipment
damage.
24 VDC encoder
supply
Ground
connection
continuity
Encoders with a supply voltage of 24 VDC are recommended for the following
reasons:
l the supply source does not need to be completely accurate. As a general rule,
these encoders use a supply format of 10…30 V.
l an on-line voltage fall is of little significance due to a substantial distance between
the module and the encoder.
In order to ensure correct operation during interference, it is vital:
l to choose an encoder with a metal casing that is referenced to the protective
ground of the connected device.
l that the ground connection is continuous between:
l the encoder,
l the shielding of the connector cable,
l the module.
256
Electronic Cam Module
Connecting the encoder supply to the CCY 1128
Introduction
The encoder supply can be connected:
l either by using a TELEFAST ABE-7H16R20 cable interface, which is then
connected to the module using a CDP ••3 cable.
l or directly, using a CDP •01 pre-wired strand
The diagram below shows the process for connecting the encoder supply.
l At 24 VDC for an encoder with a 10…30 VDC supply format,
l and at 5 VDC for an encoder with a 5 VDC supply.
TSX CCY 1128
+ + - -
104
105
106
107
108
109
110
111
112
113
114
115
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
3
4
100
101
102
103
TSX CDP
••3 cable
1
2
Process diagram
for connecting
the encoder
supply to the
TELEFAST
interface
101 102
TSX CDP
••3 cable
-0V
101 100
-0V
VRef
(1)
Supply
24 VDC
103
Supply
5 VDC
+5V
+ 24 V
FU
1
2
5V
0V
3
4
10...30 V
VRef
FU
(1) to control encoder supply at 66% of voltage provided.
Connection only to be made if supply voltage 10…30 VDC
257
Electronic Cam Module
Catalog of
CDP ••3
connector cables
Diagram
showing the
process for
connecting the
supply using a
CDP •01
pre-wired strand
The table below gives the different references for the cables connecting the
TELEFAST to the module, and their respective lengths.
Cable references
Cable lengths
CDP 053
0.5 meters
CDP 103
1 meter
CDP 203
2 meters
CDP 303
3 meters
CDP 503
5 meters
The diagram below shows the process for connecting the encoder supply.
l At 24 VDC for an encoder with a 10…30 VDC supply format,
l and at 5 VDC for an encoder with a 5 VDC supply.
TSX CCY 1128
Cable
TSX CDP •01
HE 10
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
White
Brown
Green
Yellow
VRef
(1)
Fu + 5 VDC
0 VDC
Fu
+ 24 VDC
TSX CDP •01 cable
TSX CDP •01 cable
Catalog of CDP
•01 connector
cables
258
(1) to control encoder supply at 66% of voltage provided.
Connection only to be made if supply voltage 10…30 VDC
The table below gives the different references for the cables connecting the
TELEFAST to the module, and their respective lengths.
Cable references
Cable lengths
CDP 301
3 meters
CDP 501
5 meters
Electronic Cam Module
Recommendations
l Maximum length of wires between the supply outputs and the connection points
on the TELEFAST: must be less than 0.5 meters.
l Protection on the + supply: although the module has several built-in protection
systems to guard against wiring errors and accidental short-circuits on the cables,
it is vital to install a 1A maximum non-delay fuse (Fu) on the + supply.
l Connection of the 0 V supply to the protective ground: must be as close as
possible to the supply output.
Wiring rules and precautions specific to the TELEFAST
Connecting or
disconnecting
the TELEFAST
You should always connect or disconnect the TELEFAST’s connectors and various
connection wires when the voltage is SWITCHED OFF:
l connecting or disconnecting the cable connectors linking the module and the
TELEFAST connector,
l connecting or disconnecting the wires linking the TELEFAST connector to the
encoder.
Length of the
connection cable
between the
module and the
TELEFAST
The table below gives the clock frequency of the transmission series according to
the distance.
Cross-section of
the wire
connecting the
module and the
TELEFAST
If
then
cable length < to 10 meters
frequency of the transmission series clock: 1 MHz
cable length < to 20 meters
frequency of the transmission series clock: 750 kHz
cable length < to 50 meters
frequency of the transmission series clock: 500 kHz
cable length < to 100 meters
frequency of the transmission series clock: 375 kHz
cable length < to 150 meters
frequency of the transmission series clock: 200 kHz
cable length < to 200 meters
frequency of the transmission series clock: 150 kHz
In order to reduce the on-line voltage falls as much as possible, please respect the
following points:
If
And
Then
The encoder is using a The distance from the
Use a wire with minimum cross5VDC supply
module to the TELEFAST is section 0.08 mm (gage 28)
< 100m
The distance from the
Use a wire with minimum crossmodule to the TELEFAST is section 0.34 mm (gage 22)
> 100m
259
Electronic Cam Module
Connecting the
encoder supply
In order to limit voltage falls with a 0V, caused by the encoder supply current, we
recommend that you wire the 0V as follows:
24 VDC or
5 VDC
Power supply
Encoder 0 VDC
Connection depending
on the encoder power
260
Electronic Cam Module
Wiring the
encoder outputs
on the
TELEFAST
If the encoder outputs have positive or negative logic with a number lower than 24,
use the following connection procedure:
If
And
Then
the encoder
outputs have
positive logic
their number is
lower than 24
l
l
wire the encoder outputs to the TELEFAST inputs,
working from the least significant to the most significant
wire the unused TELEFAST inputs to the 0V terminal
Example: 14-bit encoder
the encoder
outputs have
negative
Logic
their number is
lower than 24
l
l
wire the encoder outputs to the TELEFAST inputs,
working from the least significant to the most significant
do not wire (leave free) the unused TELEFAST inputs.
Example: 14-bit encoder
261
Electronic Cam Module
Protecting the
encoder supply
According to the encoder supply voltage, the supply should be protected as follows:
If
Then
The encoder supply voltage The protective fuse is built into the TELEFAST:
is 10…30VDC
l size: 1A
l type: fast-blow fusion.
The encoder supply voltage Provide a series fuse (Fu) for the positive supply:
is 5VDC
l calibre: to be determined by the user, dependent upon the
TELEFAST and encoder consumption
l type: fast-blow fusion
5 VDC encoder
power supply
Monitoring the
encoder supply
262
If the encoder supply voltage decreases by more than 15%, the default (EPSR
signal) is sent back to the module. If the encoder does not have a return supply, do
the following:
If
Then
No return encoder
supply
l
Connect the positive and negative EPSR of the TELEFAST:
the positive EPSR terminal of the TELEFAST to the positive
terminal of the encoder supply
l the negative EPSR terminal of the TELEFAST to the negative
terminal of the encoder supply
Analog Modules AEY/ASY
22
Cabling precautions on analog modules
At a Glance
To protect the signal from external noises induced in serial mode and from noises in
common mode, you are advised to take the following precautions.
Kind of
conductors
Use shielded twisted pairs of a minimum section of 0.28 mm2 (AWG24 gage).
Cable shielding
l For modules fitted with a screw terminal block (TSX AEY 414 and
TSX ASY 410) :
Link the cable shields, at each end, to the shield recovery terminals (grounding
terminals).
l For modules fitted with Sub-D connectors (TSX AEY 16••/8••/420 and
TSX ASY 800) :
As the number of channels is important, a minimum of a 13 twisted pair cable with
a general shield (external diameter 15 mm maximum) will be used, fitted with a
25-pin Sub-D male connector for the direct link to the module.
Connect the cable shield to the cover of the Sub-D male connector. The
connection to the PLC ground is therefore done using the tightening screws of the
Sub-D connector. For this reason, the Sub-D male connector must be screwed
onto its female base.
Association of
connectors in
cables
Grouping into multi-pair cables is possible for signals of the same type and which
have the same reference in relation to the ground.
Cable routing
Keep the measurement wires as far as possible from the discrete input/output
cables (particularly relay outputs) and the cables which transmit "power" signals.
263
Analog Modules
Reference for
sensors in
relation to the
ground
To ensure correct operation of the acquisition device, the following precautions are
recommended :
l the sensors must be close to each other (a few meters),
l all the sensors are referenced to the same point which is linked to the module
ground.
Use of sensors
referenced in
relation to the
ground
The sensors are connected according to the following diagram :
Input + channel 0
Input - channel 0
Shielding restart
Input + channel 1
Input - channel 1
Input + channel n
Input - channel n
If the sensors are referenced in relation to the ground, this can in certain cases,
return the potential of a remote ground to the terminal block or the Sub-D
connector(s). It is therefore essential to respect the following rules :
l this potential must be lower than the security voltage: for example, 48 V max. for
France,
l connecting a sensor point to a reference potential generates a leakage current.
It is therefore necessary to check that the total leakage currents generated do not
disrupt the system.
Use of preactuators
referenced in
relation to the
ground
264
There are no particular technical constraints for referencing the pre-actuators to the
ground. For security reasons, it is however preferable to avoid returning a remote
ground potential to the terminal block , as this can be very different from the local
ground potential.
Weighing Module ISPY100/101
23
Overview
Introduction
This section contains guidelines and information for the configuration and
installation of the basic elements of the Premium hardware with regard to grounding
and EMC.
What's in this
Chapter?
This chapter contains the following topics:
Topic
Recommendations on how to install a measurement system
Page
266
Cabling precautions on the weighing module
268
Connection of the weighing module discrete outputs
269
265
Weighing Module
Recommendations on how to install a measurement system
General
Dividing up the
loads
The quality of the measurement provided by the module may be reduced
considerably if the sensor set-up and installation precautions have not been
observed. Thus in place of exhaustive information, these few lines should make you
aware of some of the precautions which need to be taken.
In a measurement system, the weighing sensors support the following weights :
l the maximum weight to be weighed,
l the weight of the loading receiver and its structures (or metrological tare).
This total weight is divided up between 1, 2, 3, 4, 6, even 8 sensors. The design of
the mechanical structures, the shape of the loading receiver and the dividing of the
load on or within the receiver, means that the total weight is not always equally
divided between all the sensors (except of course in the case of a single sensor).
It is therefore a good idea to make sure that the dimensions of the weighing sensors
are calculated in such a way as to be able to support the total weight (maximum
weight + tare) to which they will be subjected
Inhibiting
interference on
the load receiver
As a weighing sensor deflection is very weak (a few tenths of a millimeter), all
interference on the load receiver or any friction on the permanent framework will
cause an invalid weight measurement and make correct adjustment of the module
impossible.
Mechanical
installation of the
weighing
sensors
The sensors in traction or compression must be used vertically respecting their
action direction (traction or compression). The maximum admissible tolerance on
the installation’s verticality is in the region of the degree according to the installation
and the required precision.
Protecting the
sensors from
interference
currents
It is recommended that each sensor be provided with a mass flex which plays the
role of the electric " shunt " with the aim of protecting sensors from currents capable
of circulating in the metallic framework (ground currents, from the terminal to be
connected, and electrostatic discharges…).
This flex will be of a sufficient length to not result in mechanical constraints and it will
be placed directly next to the sensors, between the permanent framework and the
load receiver.
266
Weighing Module
Contact with
water and
corrosive
products
Weighing sensors are manufactured as waterproof. It is recommended, however,
that they be prevented from coming into contact with water, corrosive products and
direct sunlight.
Preventive
maintenance of
the installation
and accessories
The weighing module requires no special maintenance. The weighing sensors,
however, should be cleaned periodically if used in a difficult environment.
It is advisable to periodically test and service the mechanical state of the load
receiver.
l Cleaning the receiver and its structures because of a product deposit or various
material deposits may result in a noticeable variation of the tare.
l Checking the verticality of the weighing sensors.
l Checking the sensor and actuator states according to their period of use.
l Etc ...
Note: Statistics show that 90% of breakdowns occurring on a weighing/dosing
installation are not attributable to the electric command device, but to the
installation itself (defective limit switches, mechanical faults…).
267
Weighing Module
Cabling precautions on the weighing module
At a Glance
To protect the signal from external noises induced in serial mode and from noises in
common mode, you are advised to take the following precautions.
Kind of
conductors
Use shielded twisted pairs of a minimum section of 0.28 mm 2 (AWG24 gage).
Cable shielding
The measurement cable shielding should only be connected to the ground on the
module side. If problems arise, if the grounds on either side of the connection are of
good quality, then both ends of the shield can be connected to the ground.
On the Sub-D connectors connect the cable shield to the cover of the connector, the
PLC ground being connected by the tightening screws of the Sub-D connector. For
this reason, the male Sub-D connector must be screwed onto its female connection
base.
Cable routing
Keep the measurement wires as far as possible from the discrete input/output
cables (particularly relay outputs) and the cables which transmit "power" signals.
Avoid :
l parallel routing (maintain a distance of at least 20 cm between the cables),
l and cross them at right-angles.
Note: The measurement input is grounded via the module.
268
Weighing Module
Connection of the weighing module discrete outputs
General
Weighing module discrete outputs are used to trigger actions on threshold crossing.
This functionality is used in the "filling machine" application.
Discrete outputs are connected using a screw terminal block :
S0 (Discrete Out 0)
Charge
S1 (Discrete Out 1)
Charge
Common
Common
The common 2 and 3 are linked by the card.
Characteristics
of the discrete
outputs
The following table shows the characteristics of the discrete outputs of the module
TSX ISP Y100/101 :
Discrete output
Characteristics
Number of channels
2
Type
A transistors
Response time
1 ms discrimination. The point where the threshold
between two measurements is crossed is
calculated by millisecond interpolation
Nominal supply voltage
24 V
Insulation voltage
1500 Veff
Maximum current
500 mA
Protection
Polarity and short-circuit inversion
Provide a fuse on the pre-actuators +24 V
269
Weighing Module
Protection
The outputs are galvanically protected by the ground.
Each of the two output channels is protected against:
l short-circuits and overloads
l polarity inversions
Note: In order to best protect against polarity inversions, it is essential to place a
fast-acting fuse on the supply, upstream of the load (shown as Fu in the diagram
above).
270
Networks
VII
Overview
Introduction
This section contains product specific guidelines, installation instructions and
information about grounding and EMC for networks.
It contains the same information as the documentation provided with the products.
What's in this
Part?
This part contains the following chapters:
Chapter
Chapter Name
Page
24
Profibus
273
25
Interbus
285
26
Ethernet
293
27
Modbus Plus Network
323
28
RIO Network
329
271
Networks
272
Profibus
24
Overview
Introduction
This chapter contains product specific guidelines, installation instructions and
information about grounding and EMC for Profibus components.
It contains the same information as the documentation provided with the products.
What's in this
Chapter?
This chapter contains the following topics:
Topic
Page
Wiring
274
Grounding and Shielding for Systems with Equipotential Bonding
275
Grounding and Shielding for Systems without Equipotential Bonding
276
Surge Protection for Bus Leads (lightning protection)
278
Static Discharge in Long PROFIBUS DP Cables
281
Capacitive By-Pass Terminal GND 001
282
273
Profibus
Wiring
Guidelines for
Bus Segment
Installation
The following guidelines apply for wiring bus segments:
l Type "A" bus cable which complies with PROFIBUS standards is to be used the
bus.
l The bus cable may not be twisted, pinched or stretched.
l A bus segment must be fitted with a termination resistor on both ends.
The corresponding slave must be live at all times so that the termination resistor
is effective however.
l Bus nodes that do not terminate a segment can be separated from the bus
without interrupting regular data traffic.
l Branch lines are not allowed.
Wiring in
Buildings
In Cabinets
Cable locations play a major role in the resistance to interference. Therefore, the
following guidelines are applied:
l Data lines must be separated from all AC and DC power lines >= 60 V.
l A minimum spacing of 20 cm is to be kept between data lines and power lines.
l AC and DC feed wires > 60 V and <= 230 V must be run separately from AC and
DC power feeds > 230 V
Separated means that the cables are in different cable bundles and ducts.
l PG screws with integrated grounding are not allowed.
l Cabinet lighting must be done with EMC safe lights and wiring.
Outside of Cabinets
l Cables must be run in metal cable ducting (lines, troughs, ducts or tubing)
wherever possible.
l Only wires of < 60 V or shielded < 230 V may be run in common cable ducts.
Dividers in metal cable ducts may be used as long as the minimum spacing of 20
cm is kept between wires.
l PROFIBUS data lines must be run separately in metal cable ducts.
Wiring outside of
buildings
Generally, the same rules apply for running lines outside of buildings as within.
However, the following applies to bus cable:
l Run in a suitable plastic tubing.
l When burying cables, only cable that is specifically designed for this purpose may
be used.
Pay special attention to the permitted temperatures.
l When running cables between buildings, use Surge Protection for Bus Leads
(lightning protection), p. 278.
l For baud rates over 500 kBaud, fiber optics cable is recommended.
274
Profibus
Grounding and Shielding for Systems with Equipotential Bonding
Central Shielding
Measures
Each cable shield should be galvanically grounded with the earth using FE/PE
grounding clamps immediately after the cable has been connected to the cabinet.
This example indicates the shielding connection from the PROFIBUS cable to the
FE/PE rail.
PROFIBUS cable
PE / FE rail
or
clamp provides contact
with the cable
FE
Note: An equalization current can flow across a shield connected at both ends
because of fluctuations in ground potential. To prevent this, it is imperative that
there is potential equalization between all the attached installation components
and devices.
This example indicates the system components and devices in a system with
equipotential bonding.
Main switching cabinet
Quantum
with
DP master
1
Substation "1"
1
Substation "n"
1
1
FE/PE rail
2
PROFIBUS DP cable
3
equipotential bonding
conductor > 16 mm2
2
3
275
Profibus
Grounding and Shielding for Systems without Equipotential Bonding
Principle
Note: Basically, grounding and shielding is to be carried out the same as for
systems with equipotential bonding.
If this is not possible because of system or construction specific reasons however,
distributed ground with a capacitive coupling of high frequency interference signals.
Procedures
Overview
This representation shows distributed grounding with capacitive coupling
Main switching cabinet
Quantum
with
DP master
1
Substation "1"
3
3
2
276
Substation "n"
1
FE/PE rail
2
PROFIBUS DP cable
3
Capacitive by-pass terminal
GND 001
Profibus
Distributed
Grounding with
Capacitive
Coupling
This table shows you the steps in setting up distributed grounding with capacitive
coupling.
Step
Action
1
Galvanically ground the shielding
(only) to the end of the bus cable and
with as much surface area as possible
to the central cabinet
2
Run the bus cable from there to the
last bus node, without any other
ground connections
3
Shielding for all bus nodes should be
ground "capacitive only"
This is done with e.g. the GND 001
terminal connection.
4
Refer to the Connection Example,
p. 282 and the Making Shielding
Connections, p. 283 in the instructions
for the corresponding device.
Comments
This is achieve at least one discharge
route for high frequency interference
Note: A transient current cannot flow
without a galvanic connection
277
Profibus
Surge Protection for Bus Leads (lightning protection)
Surge Protection
for Bus Leads up
to 12 Mbps
Signals
Connection rules
for protection
devices
To protect transmission systems from extraneous surges (lightning), the PROFIBUS
DP lead should be equipped with suitable surge protection equipment once it
extends outside a building.
The nominal discharge current should, in this case, be at least 5 kA.
The following lightning arrestors e.g. type CT MD/HF5 and type CT B110 from
Dehn und Söhne GmbH & Co KG may be used. Addresses and order numbers for
these devices can be found in the appendix under ).
For adequate protection of a PROFIBUS DP cable, two sets of protection equipment
are required for each building. The first set of protection devices (type B110), located
where the cable enters the building, works as a lightning conductor, the second (type
MD/HF5), located near the first device, works as a surge protection device.
Before connection of the protection devices please observe the following rules:
l Install a functional ground (equipotential bonding rail)
l Install the protection equipment near the functional ground, to keep surge current
path as short as possible.
Keep the lead to the functional ground as short as possible. (min. 6 mm2)
l The maximum lead length depends on the transfer rate.
l At transfer rates up to 500 kBaud you can configure a maximum of 4
outdoor segments with 8 pairs of protection devices (CT B110 and CT MD/
HF5).
l At transfer rates of 1 MBaud or higher, you may only configure one outdoor
segment with 2 pairs of protection devices.
l Do not confuse the IN and OUT ends of the lightning arrestor (IN = outdoor end)
l Make certain that you Shield grounding with protection devices, p. 280 according
to the type of lightning arrestor (CT B110 or CT MD/HF5) that is used.
278
Profibus
Protection
device
connection plan
Protection device connection plan:
Structure 1
Structure 2
Bus node
Bus node
Switching
cabinet
Switching
cabinet
Outdoor
1
2
2
1
Type and number of lightning conductors made by the firm Dehn und Söhne GmbH
&Co KG suitable for a PROFIBUS DP cable
No.
Model
Number per group
1
CT MD/HF 5
2
2
CT B110
2
Note: Information about assembly and connection of the cables can be found in
the relevant installation instructions that come with lightning arrestor.
279
Profibus
Shield grounding
with protection
devices
Direct or indirect shield grounding are offered by the protection devices. An indirect
grounding occurs using gas conductors.
In both cases EMC spring terminals grasp the input and output sides of the cable
shield.
Note: When the system permits it, we recommend you use direct shield grounding.
Types of shield grounding assignment
Type of grounding
Technique
Direct shield grounding
Connect the shield of the incoming cable to the IN terminal, and
that of the outgoing cable to the OUT terminal. The shields are
now galvanically connected with PE.
Indirect shield grounding
using gas conductors
Connection of the shield as described for direct shield
grounding. Insert the gas-type surge protector in the rack
beneath the cabinet connection terminals on the input side.
Note: Further information about grounding and shield grounding can be found in
the relevant installation instructions that come with the lightning arrestor.
280
Profibus
Static Discharge in Long PROFIBUS DP Cables
Static Discharge
Very long bus cables, which have been laid but not yet connected, are discharged
as follows:
Step
Action
1
Select the PROFIBUS DP connector closest to the FE/PE grounding clamp.
2
Touch the metal of the connector housing to the cabinet's FE/PE grounding
clamp to discharge any static electricity.
3
Now connect the bus connector to the device.
4
Discharge the other PROFIBUS DP cable connectors as described in steps 2and
3.
Notes
Note: During mounting, the metal part of the PROFIBUS DP connector is
connected internally to the cable shield. When the bus cable connector is inserted
into the module’s PROFIBUS port, a short connection between the shield and the
FE/PE is created automatically.
281
Profibus
Capacitive By-Pass Terminal GND 001
Overview
Distributed grounding with capacitive by-passing is used in systems without
equipotential bonding.
Mount the Schneider by-pass terminal (GND 001) as shown in the following
representations.
Connection
Example
This example shows the connection from the PROFIBUS cable to the by-pass
terminal.
2
4
282
1
5
1
GND 001
2
Shielding
3
Connection to Rail
4
PROFIBUS cable entering switching cabinet
5
PROFIBUS cable exiting switching cabinet
3
Profibus
Making Shielding
Connections
This example shows the shielding connection with the PROFIBUS cable.
Copper shield foil
(included)
Note: The by-pass for the bus ends is to be prepared on one cable only
283
Profibus
284
Interbus
25
Overview
Introduction
This chapter contains product specific guidelines, installation instructions and
information about grounding and EMC for Interbus components.
It contains the same information as the documentation provided with the products.
What's in this
Chapter?
This chapter contains the following topics:
Topic
Page
Momentum Communication Adapter Ground Screw Installation
286
Central Shielding Measures for the INTERBUS
288
Overvoltage Protection for Remote Bus Lines (Lightning protection)
289
285
Interbus
Momentum Communication Adapter Ground Screw Installation
Overview
Recently revised to meet new Interbus standards for electrical noise immunity,
select Momentum products have been updated with an additional ground screw.
This second ground screw is being added to all new and upgraded Momentum
products. Currently, three communication adapters have been updated. They are:
l Momentum Interbus Communication Adapter (170 INT 110 03), which supports
the diagnostic functions of a Generation 4 Interbus Master and is compliant with
Interbus certification, version 2
l Momentum Ethernet Communication Adapter (170 ENT 110 01), version 2
l Momentum FIP IO Communication Adapter (170 FNT 110 01), version 5
These communication adapters contain a new grounding system, which was
originally required to meet the revised Interbus electrical noise immunity standard
(ability to pass a 2.2kv electrical fast transient burst test). This grounding system
includes a ground screw in the communication adapter, which is connected to a
fixed standoff-ground nut on the printed circuit board and to a standoff on selected
Momentum I/O modules.
Note: This electrical noise immunity requirement only applies to systems that
require Interbus certification, version 2, and not to any other communication
network that Momentum I/O currently uses.
Momentum I/O
Modules
286
The Momentum I/O modules, which include the fixed standoff-ground nut assembly
and the male-female standoff, and accept ground screws, are:
Name
Description
170 ADM 350 10 PV .05
24 VDC 16 Input/16 Output Module
170 ADM 350 11 PV .05
24 VDC 16 Input/16 Output Fast Response Module
170 ADI 340 00 PV .04
24 VDC 16 Input Point Module
170 ADI 350 00 PV .05
24 VDC 32 Input Point Module
170 ADO 340 00 PV .04
24 VDC 16 Point Output Module
170 ADO 350 00 PV .04
24 VDC 32 Point Output Module
170 ADM 370 10 PV .04
24 VDC 16 Input/8 Output @ 2 amps Module
170 AAI 030 00 PV .05
Analog 8 Channel Differential Input Module
Interbus
Required Tools
The only tool required to install the ground screw is a PZ 1 Phillips head screwdriver.
The recommended torque on the ground screw is 0.7Nm (.51 ft-lb).
Installation
These communication adapters will be shipped with the ground screw attached in a
separate plastic bag. The above I/O modules will be shipped with a standoff in a
separate plastic bag along with an I/O module label. To install the ground screw,
follow the steps below. Refer to the figure below for the screw locations.
Step
Action
1
Install the standoff into the threaded fixed standoff-ground nut assembly, which
is located on the I/O module’s printed circuit board.
2
Snap the communication adapter onto the I/O module. Follow the same
procedure as all other Momentum products. (For more information on
communication adapter assembly, refer to Chapter 3 of Modicon Momentum I/
O Base User Guide (870 USE 002 00).
3
Install the ground screw through the top of the communication adapter.
Ground screw installation:
Standard screw M3-6
Communication adapter cover
Male-female standoff
Added standoff
287
Interbus
Backward
Compatibility
The above I/O modules can also be used with any of the Momentum communication
or processor adapters that do not include the ground screw.
CAUTION
POSSIBLE EQUIPMENT FAILURE
When using the new version of the above I/O modules with any
communication or processor adapter, do not install the standoff into the
fixed standoff-ground nut assembly on the I/O module’s printed circuit
board. The standoff could touch some of the components on the
adapter, which may cause faulty operation or product failure.
Failure to follow this precaution can result in injury or equipment
damage.
Central Shielding Measures for the INTERBUS
Central shielding
measures
For the commissioning phase, a large surface area connection should be made
between each cable shield and ground (FE/PE rail) directly after the cable enters the
switch cabinet.
Static discharge
Very long bus cables, which have been laid but not yet connected, are discharged
as follows:
Step
Notes for
connection the
cable shield with
earth
288
Action
1
Begin with the static discharge with the INTERBUS plug nearest to the FE/PE
rail.
2
Touch the FE/PE rail of the switch cabinet with the metal of the plug case.
3
Then plug the bus plug into the device, but only after this has been statically
discharged.
4
Discharge the cable’s other INTERBUS plugs in the same way and then plug
these into the device.
Note: The metal guide of the INTERBUS plug is internally connected with the cable
shield during the construction of the cable. If the bus cable plug is plugged into the
module’s INTERBUS interface, a short connection is automatically established
between the shield and PE.
Interbus
Overvoltage Protection for Remote Bus Lines (Lightning protection)
Overvoltage
protection
Connection rules
for protection
devices
To protect the transmission equipment from coupled voltage spikes (lightning
strike), overvoltage protection equipment should be used in the remote bus cables,
as soon as it is laid outside of buildings.
The nominal discharge current should, in this case, be at least 5kA.
The lightning arrestors Type VT RS485 and Type CT B110 from Dehn und Söhne
GmbH & Co KG can, for example, be used. For the supplier address and order
numbers for protection equipment and accessories, see .
To protect an INTERBUS cable, two protection device groups are required in each
building. The first group (Type B110) is positioned where the cable enters the
building and is used as the lightning conductor. The second group (Type RS485),
close to the first node, is the overvoltage protection device.
Before connection of the protection devices please observe the following rules:
l Install a functional ground (equipotential bonding rail)
l Assemble the protection devices near the building ground, so that the overload
current is diverted along the shortest route.
The cable(minimum 6mm2) to the building and functional ground should be as
short as possible.
l A maximum of 10 protection devices connected in series with 4 open land
sections, for connecting buildings to each other, are allowed in the INTERBUS
cables.
l Perform a Shield grounding (See Shield grounding with protection devices,
p. 291) of the INTERBUS lead according to the lightning arrestor used (type CT
B110 or type VT RS485).
289
Interbus
Protection
device
connection plan
Protection device connection plan:
Structure 1
Structure 2
Bus node
Bus node
Switch
cabinet
Switch
cabinet
Outdoor
1
2
2
1
Type and number of the lightning arrestors from Dehn und Söhne GmbH &Co KG
for a remote bus cable LiYCY (INTERBUS):
No.
Type
Number per group
1
VT RS485
1
2
CT B110
3
Note: Information about assembly and connection of the cables can be found in
the relevant installation instructions that come with lightning arrestor.
290
Interbus
Shield grounding
with protection
devices
Direct or indirect shield grounding are offered by the protection devices. An indirect
grounding occurs using gas conductors.
The construction of the shield grounding depends on the type of lightning arrestor.
Lightning
Direct shield grounding
arrestor type
Indirect shield grounding using gas
conductors
CT B110
Connection of the shield as described
for direct shield grounding.
Put the gas conductor in the unit
underneath the shield connection
terminal on the input side.
Connect the shield of the incoming
remote bus cable at connection IN
and that of the remote bus cable at
connection OUT. The shields are
now galvanically connected with
PE.
EMC cage clamp terminals fasten the remote bus cable shield on the input
and output sides.
VT RS485
Connect the shield of the incoming
remote bus cable at connection
IN2 and that of the remote bus
cable at connection OUT2.
Connect the shield of the incoming
remote bus cable at connection IN1,
and the remote bus cable shield at
connection OUT1. The gas conductor is
installed in the device.
Note: Connect the grounding terminals of the lightning arrestor to the PE.
Note: Further information about grounding and shield grounding can be found in
the relevant installation instructions that come with the lightning arrestor.
291
Interbus
292
Ethernet
26
Overview
Introduction
This chapter contains product specific guidelines, installation instructions and
information about grounding and EMC for Ethernet components. It contains the
same information as the "Transparent Factory" product documentation - but is
included here as a general information source for Ethernet.
What's in this
Chapter?
This chapter contains the following sections:
Section
Topic
26.1
Basic rules
Page
295
26.2
Wiring regulations
303
26.3
Using the cable runs
306
26.4
Inter building links
317
26.5
Using optical fiber
320
293
Ethernet
294
Ethernet
26.1
Basic rules
Rules and precautions
Introduction
The following chapter describes the rules and precautions to be taken to install
ethernet cabling under the optimum conditions.
What's in this
Section?
This section contains the following topics:
Topic
Page
Presentation
296
Earth and ground connections
297
Differential Mode and Common Mode
299
Wiring the ground connections and the neutral
300
Choice of Transparent Factory electric wiring
301
Sensitivity of the different families of cables
302
295
Ethernet
Presentation
Description
You have to take some precautions before installing a Transparent Factory system.
The following explains which cabling to choose, why and how to install it to obtain
entire satisfaction.
Principles
l Equipment complying with industrial standards (electromagnetic compatibility or
"EMC") works well independently.
l Precautions must be taken when equipment is connected so that it works in its
electromagnetic environment depending on its destination.
Exclusive use of Transparent Factory insulated optical fiber cables is the way to get
over any EMC problems on these links.
Note: EEC labeling must be used in Europe. This labelling does not guarantee the
actual performance of the systems with regard to CEM.
296
Ethernet
Earth and ground connections
Introduction
An earthing network carries leakage current and fault current from equipment,
common mode current from external cables (electricity and telecoms mainly) and
direct lightning currents into the earth.
Description
Physically, weak resistance (relative to a distant earth), does not concern us as
much as the local equipotentiality of the building. In fact the most sensitive lines are
those that connect equipments together. In order to restrict the circulation of
common mode currents on cables which do not leave the building, it is necessary to
restrict the voltage between interconnected equipments within the site.
A mechanical ground is any hardware conducting part which is exposed, which is
not normally live, but which could be in case of a failure.
CAUTION
Simultaneous accessibility of 2 mechanical grounds
Two mechanical connections which are simultaneously accessible
must have a lower contact voltage "U" than the conventional limit
contact voltage (25 or 50 V depending on the case).
Failure to follow this precaution can result in injury or equipment
damage.
297
Ethernet
Principle
Basically nothing else has any effect on people's safety, in particular the earthing
resistance or the method of connecting the mechanical grounds to the earth.
Equipments and electronic systems are interconnected. The best way to ensure that
everything works properly is to maintain good equipotentiality between equipments.
Besides the safety of the personnel, which is a LF (Low Frequency) constraint,
equipotentiality between equipments must be satisfactory, especially for digital
equipments even at very high frequencies.
CAUTION
Safety regulations
In case of dispute, safety regulations take precedence over EMC
constraints.
If there is a difference between the recommendations of this manual
and the instructions of a particular piece of equipment, the equipment
instructions take precedence.
Failure to follow this precaution can result in injury or equipment
damage.
298
Ethernet
Differential Mode and Common Mode
Differential Mode
Differential mode is the normal way of transmitting electric and electronic signals.
The Transparent Factory data in electric form are transmitted in differential mode.
The current is propagated on one conductor and returned on the other conductor.
The differential voltage is measured between the conductors.
When the one way and return conductors are side by side as in Transparent Factory
cables and far away from disturbing currents, the differential mode disturbance is
usually not significant.
Differential Mode
IDM
IDM
Common Mode
UDM
Common mode is an interference mode where the current is propagated in the
same direction on all the conductors and returns via the mechanical ground.
Common Mode
ICM
ICM
UCM
A mechanical ground (a conducting frame for instance), serves as a potential
reference for the electronics and as a return for common mode currents. Any
current, even a strong one, coming in one cable, in common mode into a unit which
is insulated from the ground connections, comes out through the other cables,
including Transparent Factory cables when they exist.
299
Ethernet
Wiring the ground connections and the neutral
Linking the
ground
connections
When the ground connections are not linked properly, a cable, bearing a common
mode current, disturbes all the others (including the Transparent Factory electric
cables). Proper interlinking of ground connections reduces this.
Good methods for wiring the ground connections and therefore for interlinking them,
applicable for cabinets and also for machines and buildings, are explained in the DG
KBL E manual which can be ordered separately.
Note: HF interference, conducted in common mode cables, is the main problem in
EMC.
Wiring the
neutral
The TN-C neutral diagram, which confuses the neutral conductor (marked N, which
is live) with the shielding conductor (marked PE) allows strong currents to pass
through the ground connections.
The TN-C neutral diagram is therefore harmful to the magnetic environment.
The TN-S neutral diagram (with or without shielding from residual differential
current) is much better.
Note: However, local safety regulations must always be scrupulously observed.
300
Ethernet
Choice of Transparent Factory electric wiring
Screened cables
The choice of screen quality depends on the type of connection. SCHNEIDER
ELECTRIC defines the cables for each field bus and each local network in order to
ensure the installation's electromagnetic compatibility.
A screened cable provides excellent protection against electromagnetic
disturbance, especially at high frequencies. The efficiency of a screened cable
depends on the choice of the screen and, to a greater extent, on how it is
implemented.
Note: Transparent Factory cables have a ring and a braid.
Ring cables
The problem with ring cables is that they are fragile. The HF protective effect of a
ring cable is damaged through the general handling of the cable.
Always reduce any pulling or twisting of Transparent Factory cables to a minimum,
especially on installation.
The protective effect can reach several hundreds with a simple braid from a few MHz
upwards, when the screen connections are acceptable.
Note: Bilateral connection of the screen to the exposed conductive parts protects
against the most severe disturbance.
This is why it is essential to properly equip each end of the Transparent Factory
screened cables with RJ45 screened connectors.
Twisted pair, screened and ring cables
301
Ethernet
Sensitivity of the different families of cables
Description
302
Descriptive table
Family
Cables
Composition
EMC behavior
1
…analog
supply and reading circuits for
analog sensors
These signals are sensitive
2
….digital and
telecomm
digital and data bus circuits
These signals are sensitive
including Transparent Factory They are disturbing for family
1 if they are not enough
shielded
3
….relaying
dry contact circuits with refiring These signals interfere with
risks
families 1 and 2
4
…supply
supply and power circuits
These signals cause
disturbance
Ethernet
26.2
Wiring regulations
Rules to follow by the fitter
Introduction
The fitter must, except if it's not possible, follow the following rules.
What's in this
Section?
This section contains the following topics:
Topic
Page
First wiring rule
304
Second wiring rule
305
Third wiring rule
305
303
Ethernet
First wiring rule
Principle
It is desirable to flatten any connection against equipotential exposed
conducting structures in order to take advantage of the HF protection effects.
Using conductor cable runs leads to a satisfactory level of protection in most cases.
As a minimum requirement, you should ensure that connecting cables between or
inside buildings also have a ground connection: earthing cable or cable run.
For internal connections to cabinets and to machines, the cables shall be systematically flattened against the metal supports.
To maintain the correct protective effect it is advisable to observe a distance
between cables of more than 5 times the radius "R" of the largest one:
d > 5R
Positioning the cables
Interference cable
304
Signal cable
Ethernet
Second wiring rule
Principle
Only analog, digital and telecommunication signal pairs can be tight together
in one bundle.
The relay, variator, supply and power circuits shall be separated from the pairs
above.
Take special care when setting up the variable speed controllers to separate the
power connections from the data connections.
Everytime it is possible a duct should be reserved for power connections, even in
the cabinets.
Third wiring rule
Principle
The power cables do not need to be shielded if they are filtered.
Thus, the power outputs of the variable speed controllers must be either shielded or
filtered.
305
Ethernet
26.3
Using the cable runs
Basics
Introduction
This chapter describes the basics about cable runs installation.
What's in this
Section?
This section contains the following topics:
306
Topic
Page
Basics on how to use cable runs
307
Verification modes of the length of a homogeneous cable
312
Verification mode of a the length of a heterogeneous cable
314
Other protective effects
315
Ethernet
Basics on how to use cable runs
Metal cable runs
Outside the cabinets, beyond a distance of 3 m, the ducts must be metal. These
cable runs must have electrical continuity from end to end via fish plates or foils.
It is very important to set up connections using fish plates or foils rather than using
a braid or even a round conductor. These cable runs must be connected in the same
way to the cabinet and machine connections, if necessary after scraping away the
paint in order to ensure contact.
An accompanying cable will only be used when there is no other solution.
Example: Use of a metallic duct
There must be electrical contact with all
connections: SCRAPE OFF the paint
307
Ethernet
Non-shielded cables must be fixed in the corners of the ducts as shown in the
illustration below.
Power or variator
cables
Non
shielded
analog cables
Relay
cables
Transparent
Factory cables
Shielded analog cables
308
Non shielded numeric
cables
Ethernet
Future
developments
Bear in mind future developments. Vertical separation in the duct avoids mixing
incompatible cables. A metal cover on the signals half duct is desirable. You must
be aware that a complete metal cover on the duct does not improve the EMC.
Efficiency of the various types of ducts
Effeciency
equivalent to
equivalent to
Transparent
Factory
For Transparent Factory, as for each communication network, an initial maximum
limit for segment length (without repeater) must be observed. This limit of 100
metres , can only be achieved if installation conditions are satisfactory with regard
to the EMC (especially: cables placed in metal ducts with end to end electrical
continuity connected to frame ground mesh and to earth system).
It is therefore necessary to define a maximum theoretical length for
electromagnetic compatibility. This second limit is theoretical and is used to optimize
installation conditions and must be observed at the same time as the previous limit.
The theoretical EMC length is 400 meters for Transparent Factory.
309
Ethernet
Separating the
cables according
to their type
Except when it is not possible, two metal ducts will be used:
l one reserved for power, relays and variators
l the other for signal cables (sensors, data, telecoms..).
These two ducts can be in contact if they are shorter than 30 m. From 30 to 100 m
they shall be spaced 10 cm apart, either side by side or one above the other.
Example of installation with 2 ducts
Power cable
Relay cables
(Non shielded)
digital cables
(Non shielded) analog
cables
TF Ethernet cables
(Shielded) analog
cables
All these particular limits come from the same EMC Theoretical Length, or "ETL".
To reach this ETL it is assumed that the following two optimum conditions have been
fulfilled:
l a second duct, at least 30 cm away, is reserved for power and relay cables,
l the ducts are not filled to more than 50% of their capacity.
310
Ethernet
Ki Coefficient
Depending on the type of communication network this value can be different.
l Everytime one of both conditions is not fulfilled from end to end and in order to
observe electromagnetic compatibility, a coefficient must be assigned to the
physical duct length. These Ki coefficients, defined in the table below, measure
the decrease of the protective effect. The resulting authorized length will then be
less than the ETL.
l Similarly, in the case of a single duct for power and signal cables, the coefficient
will take into account the lack of a metal separation or metal covering on the
signal half duct.
Summary table
Symbol
Condition
Illustration
Coefficient
Total
length (1)
Ki
ETL x 1/Ki
K50
Single duct filled to 50%
or more
2
200 m
K10
Ducts 10 cm apart
(instead of 30 cm)
2
200 m
K6
Single duct or 2
contiguous ducts with
separation and cover on
the signal half duct
4
100 m
K8
Single duct or 2
contiguous ducts without
cover on the signal half
duct
6
60 m
K0
Single duct or 2
contiguous ducts without
separation
12
30 m
(1) Maximum total length if it's the unique condition against (with ETL = 400m)
311
Ethernet
Verification modes of the length of a homogeneous cable
Introduction
There are two ways of using the Ki coefficients.
l To obtain the authorized physical length, you take the ETL and divide it by Ki,
(examples 1 and 2 below).
l On the contrary, when particular physical lengths are imposed necessary,
multiply them by Ki and compare the result with the ETL to check that you are
compliant with the EMC requirements (examples 3,4, and 5).
Example 1:
Transparent
Factory links
less than 30m
Wiring can then be done in a single metal run (for ETL = 400 m or more).
If the duct is not filled to more than 50% (bear in mind future developments), only the
Ko coefficient must then be taken into account, which gives a maximum length of
400 m: 12 = 30 m.
The power cables and shielded digital connections shall be fixed in the corners of
the duct as shown in the illustration below:
Power
cable
Relay cable
312
TF Ethernet cables
Ethernet
Example 2:
Transparent
Factory links up
to less than 100m
If length calculated in an installation condition is insufficient (30 m in the first
example) it will be necessary to improve the EMC aspect of the configuration.
Vertical separation in the duct avoids mixing incompatible cables. A metal cover on
the half duct of the signal cables restricts signal interference.
That's why the coefficient value then goes from 12 (=K0) to only 4 (=K6), which, (with
ETL=400) gives the maximum length: ETL / 4 = 100 m.
The EMC conditions to be observed are then:
l each half duct is filled to 50% max.,
l the separation is metallic and in contact with the duct along the whole length,
l the cover is in contact with the separation along the whole length.
Note: Bear in mind future developments.
Illustration
Power cables
Shielded numeric
cables
Relay cables
Example 3: Plan
for laying 30m of
Transparent
Factory cable
It is planned to lay the cable in a single duct filled to 70% without separation, together
with a power cable and an analog cable.
This installation condition, according to the Ki symbols table, is linked to two
coefficients: K0 (=12) et K50 (=2); you must therefore multiply the physical length by
2 and by 12.
As the result 720m (30m x12) is greater than ETL=400m, the 30m installed length
will not comply with EMC requirements. Example 4 (next §) explains a possible
solution.
313
Ethernet
Verification mode of a the length of a heterogeneous cable
Introduction
When there are multiple installation conditions along the length of a cable run, each
physical length of the same laying type must be multiplied by the relevant
coefficients following the same rules as above.
The sum of the various results must be less than ETL (Transparent Factory).
Example 4: New
laying plan for
30m of
Transparent
Factory cable
The signal cable in example 3 is laid along 10m according to the laying type above;
the remaining 20m are laid 10 cm away from the first one, in a separate duct from
the power cable, but placed .
Calculation table
Length
Ki coefficients
Calculations
Results
10 m
K0 (=12) et K50 (=2)
10 m x 24
240 m
20 m
K10 (=2) et K50 (=2)
20 m X 4
80 m
240 m + 80 m
320 m
Total (30 m)
As the resulting 320m is now less than ETL = 400m, the 30 m installed length will
comply with EMC requirements.
Example 5:
Laying plan for a
1000m FIP cable
The documentation for the system shows that the first limit is observed, provided
only if main cable (150 ohms single pair large gage) is used.
The ETL value for this technology is 2000 m.
Let us assume that the 2 optimum conditions are observed for 700m and that for the
rest of the length the power duct is:
l filled to more than 50%,
l and only 10cm away from the signal duct.
Calculation table
Length
Ki coefficients
700 m
no
300 m
K50 (=2) et K10 (=2)
Total (1.000 m)
Calculations
Results
300 m X 4
1.200 m
700 m +1.200 m
1.900 m
700 m
As the result 1900m is less than ETL=2000m, the installed length will comply with
EMC requirements and only the previous contingency remains (no small gage pair).
314
Ethernet
Other protective effects
Introduction
The protective effect of a cable run is about 50 between 1 MHz and 100 MHz.
If you cannot use this type of hardware, other protective effects are possible.
Soldered wire cable runs "cablofils" are less effective and often more expensive than
metal ducts.
Cablofil
Protective effect #10
Protective effect #5
315
Ethernet
Grounding cable
Protective effect #5
ground cable
316
Ethernet
26.4
Inter building links
Introduction
Presentation
This chapter gives the precautions and recommendations for inter building wiring.
Note: It is strongly recommended to use optical fiber cable for data links and
therefore for Transparent Factory between buildings. This type of link is used to
eliminate loop problems between buildings.
What's in this
Section?
This section contains the following topics:
Topic
Page
Wiring electrical connections
318
Protection against intrusion
319
317
Ethernet
Wiring electrical connections
Principle
Inter building links present two special features that can introduce risks for the
installation:
l the poor equipotentiality between installation grounds,
l the large areas of loops between the data cables and the grounds.
Note: Before installing and connecting a data cable between two buildings, you
must check that the two ground connections (one at each building) are
interconnected.
All the exposed metal parts accessible at the same time must be connected to the
same ground connector (or at least to a set of interconnected ground connections).
This requirement is fundamental to ensure people's safety.
The second risk associated to inter building connections is the area of loop included
between the data cables and the connections.
This loop is particularly critical when there is an indirect blasting of the site. The
overvoltage caused in these loops by an indirect blasting is approximately of 100
volts per m.
Note: In order to reduce this risk, all cable runs between two buildings must be
doubled up with a large section equipotential line (»35 mm 2 ).
318
Ethernet
Protection against intrusion
Principle
Common mode currents coming from outside must be discharged to the ground
network at the entrance to the site in order to limit voltages between equipments.
Note: Any conducting lines (conducting cable, conducting pipework or insulating
pipework carrying a conducting fluid), entering in a building must be connected to
a ground at the entrance of the building and at the shortest possible distance.
Surge absorbers must be placed on electricity, telecommunications and signal cable
(for data, alarms, access checks, video supervision,….) at the entrance to the
buildings. The effeciency of such devices is largely influenced by the way they are
installed.
The surge absorbers (varistors, discharge gaps etc.) must be connected directly to
the ground connection on the electrical panel or to equipments they are protecting.
Simply connecting surge absorbers to earth (instead of the mechanical ground) is
not effecient.
As far as possible the panels, where the electrical, telecommunications and signal
protectors are installed, must be placed close to a grounding strip.
319
Ethernet
26.5
Using optical fiber
Choosing and Fitting Optical Fiber
Introduction
This chapter gives the necessary recommendations for choosing optical fibers.
What's in this
Section?
This section contains the following topics:
320
Topic
Page
Choosing the optical connection type
321
Fitting the optical patches
321
Ethernet
Choosing the optical connection type
Choosing the
optical fibers
Schneider Electric supplies Transparent Factory equipments with optical ports:
modules, hubs and switches. What all those equipments have in common is that it
is used to connect silica multimode fibers. Each optical connection needs two
fibers.
From one end to the other these fibers must be 62.5/125 type and specified to allow
communication on wavelengths 850 nm and 1300 nm.
Choosing the
optical cables
The cable must include a minimal amount and maximal quality of fibers as described
in the previous paragraph. Furthermore, it can contain other fibers or electrical
conductors.
Its protection must be compatible with the installation conditions.
Fitting the optical patches
Definition
The optical strings necessary to connect the Control Intranet modules, hubs and
switches are supplied in 5 meter lengths with the options of suitable optical
connectors.
MT-RJ / SC duplex optical patch (490NOC00005)
MT-RJ / ST duplex optical patch (490NOT00005)
321
Ethernet
MT-RJ / MT-RJ optical patch (490NOR00005)
Two important precautions must be taken by the installer and the user :
l 1. Do not bend these stringss (the minimum radius is 10 cm).
l 2. Pull or twist the cable and its connectors as less as possible.
On the other hand, there is no minimum distance to be observed between an
optical cable and any cable or equipment which could interfere with it. Special cases
of strong ionizing rays is not the purpose of this manual.
322
Modbus Plus Network
27
Overview
Introduction
This chapter contains product specific guidelines, installation instructions and
information about grounding and EMC for Modbus Plus network components. It
contains the same information as the documentation provided with the products.
What's in this
Chapter?
This chapter contains the following topics:
Topic
Page
Modbus Plus Termination and Grounding
324
Fiber Repeaters
327
323
Modbus Plus Network
Modbus Plus Termination and Grounding
How taps have to
be terminated
A tap is required at each site on the trunk cable to provide connections for the trunk
cable and drop cable. Each tap contains an internal terminating resistor that can be
connected by two jumpers. Two jumper wires are included in the tap package, but
are not installed. At the taps at the two ends of a cable section, you must connect
both of the jumpers to provide the proper terminating impedance for the network.
Taps at inline sites must have both jumpers removed. The impedance is maintained
regardless of whether a node device is connected to the drop cable. Any connector
can be disconnected from its device without affecting the network impedance.
The diagram shows a Modbus Plus Network connection with terminating resistors
and grounding.
W
O
GND
W
BLU
cable tie
outer shield
ground
wire
324
Modbus Plus Network
Each tap has a grounding screw for connection to the site panel ground. Modicon
drop cables have a grounding lug in the cable package. This must be tightly solded
or crimped on the cable and connected to the grounding screw on the tap.
The diagram shows a drop cable, connected and grounded with a tap.
inline site
tap
end site
tap
120
end site
tap
120
Grounding at the
tap
trunk
cable
tap
ground
drop
cable
drop
cable
connector
312
panel
ground
312
panel
ground
312
panel
ground
The node device end of the drop cable has a lug which must be connected to the
node device’s panel ground. The network cable must be grounded through this
connection at each node site, even when the node device is not present. The ground
point must not be left open. No other grounding method can be used.
325
Modbus Plus Network
Grounding at the
device panel
Modbus Plus network drop cables require a ground connection to the backplane.
The connection is made by means of a metal loop clamp that grounds the cable
shield to the ground point.
The following figure shows the Modbus Plus grounding at the device panel.
Loop Clamp
(supplied with
Modbus Plus Tap)
Modbus Plus
Drop Cable
Ground
Screws
0.5 in
(13 mm)
11.8 in
(30 cm)
min
max
Remove outer
jacket to expose
the shield braid.
Existing backplane
ground screw may be
used if wire space
and clearance allows.
MB+
Use holes along backplane
mounting flange to secure clamp.
Customer electrical panel may
need to be drilled and tapped.
Note: To maintain CE compliance with the European Directive on EMC (89/336/
EEC), the Modbus Plus drop cables must be installed in accordance with these
instructions.
Preparing the
cable for
grounding
326
This table shows the steps to prepare the cable for grounding
Step
Action
1
Determine the distance from the cable´s end connector to the intended ground
point on your backplane or panel
2
Stripping of the cable´s outer jacket
Note: Keep in mind, that the maximum allowable distance from the ground point
to the cable´s end connector is 11.8 in (30 cm)
3
Remove 0.5 -1 in (13-25 mm) of the cable´s outer jacket to expose the shield
braid as shown in the figure above. )
4
If the panel has a suitable ground point for mounting the cable clamp, install the
clamp at that point
Modbus Plus Network
Fiber Repeaters
Grounding
This table shows the steps for grounding a Modbus Plus Fiber Repeater
Step
Connecting AC
power
Connecting DC
power
Action
1
Connect the Repeater to the site ground
Result: The Repeater obtains it´s ground through the chassis ground screw or
DC (-) wire.
2
Use a continuity tester to verify, that the repeater is grounded to the site ground
This table shows the steps to supply AC power to the repeater
Step
Action
1
Remove the power at it´s source
2
If necessary install a different plug on the cable for the power source at your site
Note: The AC power cable supplied with the repeater is keyed for North
American 110-120 VAC outlets.
3
Remove the AC power cable from the repeater
4
Set the power selector plug to the 110-120 VAC or 220-240 VAC position for the
power source at your site. To do this
1. Remove the power selector plug by prying under it´s tab using a small screw
driver
2. Set the plug to the proper voltage position as shown on the plug body
3. Reinsert the plug
5
Insert the AC power cable in the rear panel connector
6
Insert the AC power cable into the power source
This table shows the steps to supply DC power to the repeater
Step
Action
1
Remove the power at it´s source
2
Connect the source to the DC power terminals, observing the proper polarity
327
Modbus Plus Network
RIO shield-tochassis switch
RIO cable shield-to-chassis switch on the rear of the repeater is used to specify the
repeater´s relationship to chassis ground.
This diagram shows the shield-to-chassis switch
JP1
1
neutral
2
This table shows the function depending on the switch position
328
Switch position
Function
1
RIO cable shield is isolated from chassis
ground by a capacitor (i.e if low frequency is
a problem)
neutral
Repeater is configured as a drop on the
optical link (shipped position)
2
RIO cable shield is connected directly to
chassis ground (i.e. the same ground as the
main RIO head)
RIO Network
28
Grounding of RIO Networks
Overview
The Remote I/O communication is based on single point grounding, that is located
at the head. Coaxial cable and taps have no additional connection to the ground.
That eliminates the low frequency ground loops.
Missing
grounding
A cable system must be grounded at all times to ensure safety and proper operation
of the nodes on the network. The cable system is grounded by the RIO head
processor. But if the cable is removed, the ground connection doesn´t work
anymore.
Ground Blocks
Ground blocks ensure grounding, even if the cable is removed.
Additional properties are as follows:
l Low insertion loss
Only if five or more are used, they have to be consider in the trunk attenuation
with 0.2 dB each. The impedance is 75 Ohms and the return loss > 40 dB
l Wide application frequency
329
RIO Network
Ground Block
structure
The ground block 60-0545-000 consists of two female in-line F connectors and a
separate screw hole binding for attaching a ground wire. The grounding block has
two mounting holes, allowing it to be mounted to a flat surface. Two styles of the
ground block 60-0545-000 are available and may be used interchangeable.
This diagram shows the dimensions of the two available 60-0545-000 grounding
blocks.
.196 Diameter (Typical)
2.332
Type A
.360
#8-32 x 7/
16
Locking Screw
.182 Diameter
Ground Wire
1.03
1/ Hex/Philips
4
Locking Screw
Type B
.35
15 ø
.75
1.97
Note: Local building codes may require the cable shield tied to ground, whenever
the cable system exits and/or enters a new building (NEC Article 820-33)
330
RIO Network
Surge protection
Surge protection is available for coaxial network trunks that span between buildings
and are exposed to lightning. The recommended product has internal gas discharge
surge protectors that absorb very high currents induced into the cable system by
near-lightning strikes. The device indicated has insertion loss of less than 0.3 dB at
the network operating frequency. The unused drop ports must be terminated with a
Modicon 52-0402-000 Port Terminator. If desired, shrink tubing may be used to seal
the F connections.
The device should be accessible for maintenance, and be protected from the
elements if installed outside. The threaded stud should be connected to building
ground.
The recommended product is Relcom Inc. p/n CBT-22300G. Contact information is:
Relcom Inc.
2221 Yew Street Forest Grove, Oregon 97116, Tel: 8003823765
www.relcominc.com
331
RIO Network
332
B
AC
Index
Numerics
2-wire cable
Using 2-wire cables for out and return
conduction of signals, 140
A
AC Actuators
Protective Circuits for, 171
Actual resistance
Influence of the actual resistance with
galvanic coupling, 67
Actuator cable
Actuator cables outside islands, 101
Alternating Current System
TT, TN, IT Systems, 36
Amateur radio transmitter, 50
Analog I/O Lines
Grounding, 175
Analog measuring circuit
Cable shield measuring circuit, 136
Analog Process Signals, 126
Cable Selection, 133
Antenna, 75
Arcing, 52
Arcing contact, 52
Arrangements
Room Arrangements from an EMC Point
of View, 84
Asymmetrically operated circuit
with common mode interference, 60
with differential mode interference, 59
Asymmetrically operated circuits, 58
Asymmetries
Unwanted Asymmetries in circuit, 62
Unwanted asymmetries in circuit, 59, 61
Atmospheric discharge, 51
B
Balancing, 83
Bandwidth of the working frequency, 83
Basic Security and Safety Requirements
(machine directive), 22
Bistable latches, 52
Body Currents
Dangerous Body Currents, Electrical
Shock, 38
Braided Shield
Cable Selection, 133
Building
Guidelines for the Grounding System in
Buildings, 98
Buried cable, 142
Burst, 54
Bus cable
Cable ducts in the cabinet, 126
C
Cabinet
Guidelines for Arranging the Devices,
120
Guidelines for Cabling in the Cabinet,
333
Index
126
Guidelines for Grounding Unused
Conductors, 139
Guidelines for Installing Filters in the
Cabinet, 128
Guidelines for Materials and Lighting in
the Cabinet, 127
Guidelines for the Reference Conductor
System in the Cabinet, 125
Partitioning in two cabinets of different
interference levels, 122
Cable
Arranging cables in cable ducts, 141
Guidelines for Cables between Buildings,
144
Guidelines for Combining Signals in
Cables, Conductor Bundles and
Connectors, 134
Guidelines for Laying Cables in Parallel
and Crossing Cables, 135
Guidelines for Selecting Cables, 133
Installing cables, 139
Principle of cable categories, 84
Using Shielded Cables, 135
Working clearance between cables, 135
Cable Duct, 69
Cable duct
Cable ducts in the cabinet, 126
Cable Ducts
Guidelines for Cable Ducts, 141
Cable entrance
Guidelines for installing cables in the
cabinet, 126
Cable Shield
Interference Current Dissipation of Cable
Shields, 126
Cable shield
Cable shield ground connections, 138
How to create a ground connection for
cable shields, 113
Cable shields
Mutual impedance of cable shields, 85
Cable spacing
Influence of the distance between cables
on the induced voltage, 71
Cable tray, 142
334
Cables between Buildings
Guidelines for Cables between Buildings,
144
Cabling
Cabling Arrangements, 84
Guidelines for Cabling in the Cabinet,
126
Capacitive Coupling
Mechanism, Size, 72
Capacitive coupling
Coupling a common mode interference,
61
Capacitive resistance
Influence of the frequency on the
capacitive resistance, 56
Carpet, 93
CAY
general precautions for wiring, 245
CE Compliance, 160
CE Mark, 19
Cell Phone, 75
Cellular Telephone, 75
Central Shielding Measures, 288
CFY
general precautions for wiring, 248
Chemical hazards, 38
Circuit, 52
Circuit breakers, 51
CISPR, 27
Class 1
Using cables for class 1 signals, 133
Class 2
Using cables for class 2 signals, 133
Class 3
Using cables for class 3 signals, 134
Class 4
Using cables for class 4 signals, 134
Closed system installation, 160
Coax cable, 58
Common Mode Interference
Definition, 60
Common mode interference, 58
Common mode-differential modeconversion, 61, 62
Common-mode interference
Filter, 87
Index
Commutation drop, 55
Component Values
for AC and DC Actuators, 172
Computer work stations, 93
Conducted interference
Sources of conducted interference, 51
Conductor
Guidelines for Grounding Unused
Conductors, 139
Conductor Bundles
Guidelines for Combining Signals in
Cables, Conductor Bundles and
Connectors, 134
Conformity Statement, 19
Connecting
cable ducts, 141
encoder count sensor, 238
encoder supply, 241
Connecting HE10 connector modules
Discrete I/O, 225
Connecting modules to TELEFAST
interfaces using an HE10 connector
Discrete I/O, 228
Connecting modules with screw terminal
blocks
Discrete I/O, 227
Connecting PSY supply modules, 196, 198
Connecting racks to the ground, 190
Connecting SUP A05 supply modules, 213
Connection of SUP 1011/1021 power
supplies, 204
Connection of SUP 1051 power supplies,
206
Connection of SUP 1101 power supplies,
208
Connection of SUP A02 power supply
modules, 211
Connector
Guidelines for Combining Signals in
Cables, Conductor Bundles and
Connectors, 134
Contact
Direct and indirect contact, 39
Contactor
Isolation of Inductances through Partition
Panels in the Cabinet, 120
Controller circuits with semi-conductors, 51
Corona, 51
Coupling
Capacitive Coupling, 72
Galvanic Coupling, 66
Inductive Coupling, 69
Overview of Interference Coupling
Mechanisms, 64
Overview, Influence Model, 49
Radiating Coupling, 75
Through space (radiated), 65
Coupling capacitance, 74
Coupling inductivity, 69
Cover, 39
Crossing cables
Guidelines, 136
D
Daisy chaining, 100
Danger of Burning, 38
Dangerous voltages, 39
Data Connection, 58
DC Actuators
Protective Circuits for, 170
DC power supply, 52
DC Resistance
Influence of the DC resistance with
galvanic coupling, 67
Device
According to the EMC Guideline, 21
Device Arrangements
Guidelines for Arranging Devices, 92
Differential amplifier, 83
Differential mode disturbance
Filter, 87
Differential Mode Interference
Definition, 59
Differential mode interference, 58
Digital signal line
Cable ducts in the cabinet, 126
Direct contact, 39
Discharge
as broad-band interference sources, 51
Discharge lamp, 51
335
Index
Disturbance
Results of Disturbance to an Industrial
Application, 48
Disturbance Variable
Definition, 49
Double shielding, 86
Drive
Arranging NC Controllers, PLCs and
Drives in a Machine Housing, 120
Drum sequencer contact, 52
E
Earth Circuit Coupling, 66
Earth plane, 98
Earth Reference Plane
Guidelines for Earthing and Grounding in
the Cabinet, 122
Earth reference plane, 125
Earthing
Combination of Earthing, Grounding and
Lightning Protection, 96
Earthing for Systems Including all
Buildings, 108
Earthing System
Guidelines for Earthing and Grounding in
the Cabinet, 122
Effective resistance
Influence of line geometry on effective
resistance with galvanic coupling, 68
Electric Shock
Causes and Preventative Measures, 39
Electrical Circuits
Symmetrically and Asymmetrically
Operated Circuits, 58
Electrical connections, 42
Electrical Shock, 38
Electromagnetic field, 75
Electrostatic Charging, 93
Electrostatic Discharge, 72
EMC Compatibility
EMC Compatible Wiring, 83
EMC Directives, 21
EMC Domain, 120
EMC Guidelines, 18
336
EMC Performance
Classification of Signals according to
their EMC Performance, 132
EN 50178, 28, 40
EN 60204, 28
EN 60439, 28
EN 60950, 28
EN 61131, 28
EN European Standard, 20
Energy hazards, 38
Energy restriction, 39
ENV European Preliminary Standard, 20
Equipotential bonding strip, 105
EU
EMC Directives, 21
Harmonized the Regulations and
Standards in the EU, 18
Machine Directives, 22
EU Guidelines, 18
European Preliminary Standard, 20
European Standard, 20
External lightning protection, 106
F
Failure
Definition, 48
Fault current-protective circuit, 39
Ferrite cores, 87
Fiber optic cable
Recommended for cables between
buildings, 144
Filter
Filtering the Mains Voltage, 117
Fundamental EMC Measures, 86
Guidelines for Installing Filters in the
Cabinet, 128
Guidelines for installing filters in the
cabinet, 126
in the cabinet, 124
Interference Current Dissipation of
Filters, 126
Floor covering, 93
Floor maintenance, 93
Fluorescent lamp, 52
Fluorescent Lamps, 75
Index
Free Conductors
Guidelines for Grounding Unused
Conductors, 139
Frequency
Influence of the frequency of a
disturbance variable, 56
Function Degradation
Definition, 48
Function Failure
Definition, 48
Functional earth, 42
Functional Earthing
Guidelines for Earthing and Grounding in
the Cabinet, 122
FX receiver, 50
G
Galvanic Coupling
Mechanism, Example, Size, 66
General rules for wiring
Discrete I/Os, 221
General Standard, 20
Geometry
Influence of line geometry on effective
resistance with galvanic coupling, 68
Grading zones for lightning protection, 107
Grid-type grounding system, 82
Ground
Definition, 34
Guidelines for Grounding Unused
Conductors, 139
Ground Connection
Current Distribution by Ground
Connections, 36
Guidelines for Creating the Ground
Connection for Cable Shielding, 136
Ground connection, 105
How to create a ground connection for
cable shields, 113
Ground Connections
Guidelines for Creating Ground
Connections, 109
Grounding
Analog I/O Lines, 175
Cabinets, 174
Combination of Earthing, Grounding and
Lightning Protection, 96
Definition, 34
DIN Rail Terminals, 174
Grounding for Systems Including all
Buildings, 108
Momentum Devices, 172
Grounding connection, 98
Grounding System, 98, 122
Definition, 34
Guidelines for the Grounding System,
103
Island Grounding System, 101
Recommended Grounding System
Connection Scheme, 103
Grounding system, 80
EMC functions of the grounding system,
80
EMC measures for grounding systems,
80
Recommended grounding system
connection scheme, 105
Scope of the grounding system, 103
Grounding System Rail, 122
Guideline
Guidelines for Materials and Lighting in
the Cabinet, 127
Guidelines
Guidelines for Arranging Devices, 92
Guidelines for Arranging the Devices,
120
Guidelines for Creating Ground
Connections, 109
Guidelines for Grounding and Earthing
for Systems between Buildings, 108
Guidelines for Grounding and Earthing in
the Cabinet, 122
Guidelines for Laying Cables in Parallel
and Crossing Cables, 135
Guidelines for Lightning and Overvoltage
Protection, 106
Guidelines for Local Grounding for
337
Index
Devices and Machines, 100
Guidelines for Power Supply, 117
Guidelines for Protection against
Electrostatic Discharge, 93
Guidelines for Selecting Cables, 133
Guidelines for the Grounding System in
Buildings, 98
Guidelines for the Reference Conductor
System in the Cabinet, 125
H
Harmonic wave, 59
Harmonized European Standards, 19
Harmonizing Document, 20
Hazards of Electrical Current, 38
HD 384.4.41, 28
HD Harmonizing Document, 20
Heat
Heat hazards, 38
Heating Line
Guidelines for Earthing and Grounding in
the Cabinet, 122
HF generator, 50
High current equipment, 92
High Frequency Device, 75
Highly Frequent Signals, 76
Housing, 39
Untreated housing cover as source of
interference, 52
I
IEC, 27
IEC 60204, 28, 40
IEC 60364, 36
IEC 60364-4-41, 28, 40
IEC 60364-5-54, 42
IEC 60439, 28
IEC 61131, 28
IEC 61131-2, 41, 43
IEC 61140, 40, 41
IEC 62103, 28, 40
IEC 950, 28
Indirect contact, 39
338
Inductances
Isolation of Inductances through Partition
Panels in the Cabinet, 120
Inductive Coupling
Mechanism, Example, Size, 69
Inductive coupling
Coupling common mode interferences,
61
Solution for transposition, 83
Inductive resistance
Influence on the inductive resistance, 56
Inductivity
Inductivities, 72
Influence of line inductivity with galvanic
coupling, 67
Influence of Interference
Principles, 49
Influential Mechanisms
Overview of Interference Coupling
Mechanisms, 64
Input impedance, 83
Installation
Guidelines for installing a ground
connection in the cabinet, 124
Installing cables, 139
Insulation, 39, 42
Doubled/reinforced insulation, 39
Interference
Types of Interference, 53
Interference Coupling
Overview of Interference Coupling
Mechanisms, 64
Interference current, 56
Interference Current Dissipation of Cable
Shields, 126
Interference Current Dissipation of Filters,
126
Interference Model, 49
Interference Parameters, 56
Interference voltage, 56
Interfering pulse
Frequency spectrum of an interference
pulse, 56
Internal lightning protection, 106
Iron Beam
as Functional Earth for a Cabinet, 122
Index
ISO, 27
Isolating switch in energy supplies, 51
IT System, 36
L
Leakage current
of shields, 86
Lighting
Guidelines for Materials and Lighting in
the Cabinet, 127
Lightning
Combination of Earthing, Grounding and
Lightning Protection, 96
Lightning arrester
Down-lead from the lightning arrester to
grounding system, 105
Lightning Discharge, 72
Lightning Discharge Current, 69
Lightning Protection, 106
Lightning protection zones, 107
Line geometry
Influence of line geometry on effective
resistance with galvanic coupling, 68
Line guided coupling, 65
Line inductivity
Influence of line inductivity with galvanic
coupling, 67
Local Grounding, 100
Loop between exposed conductive parts
Avoiding loops between exposed
conductive parts by installing cables near
the earth connection, 139
Avoiding loops between exposed
conductive parts by installing cables on
grounding structures, 139
Low Voltage Guidelines, 18
M
M type Grid-type grounding system, 82
Machine Directives, 22
Machine Guidelines, 18
Machines
According to the Machine Directive, 22
Guidelines for Arranging the Device in
the Cabinet or a Machine, 120
Main Building Systems
Guidelines for Grounding and Earthing
for Systems between Buildings, 108
Main grounding system, 98
Mains lead
Cable ducts in the cabinet, 126
Mains Voltage, 117
Maintenance, 42
Materials
Guidelines for Materials and Lighting in
the Cabinet, 127
Measuring Circuit
Cable shield measuring circuit, 136
Mechanisms
Overview of Interference Coupling
Mechanisms, 64
Meshed earthing system, 105
Metals
Guidelines for Materials and Lighting in
the Cabinet, 127
Microwave device, 50
Momentum Devices
Grounding, 172
Motor, 51, 52
Mounting processor modules, 191
Mounting Rail, 122
Multiplexer, 52
Mutual impedance
of cable shields, 85
N
Narrow-band
Examples of narrow-band sources of
interference, 50
Neutral Earthing
Guidelines for Earthing and Grounding in
the Cabinet, 122
Noise, 51
Non-periodic interference, 54
Nuclear discharge, 51
O
Oscillation, 59
339
Index
Outgoing and return conductor
Installing outgoing and return conductors
close to each other to avoid
unsymmetrical coupling, 140
Overvoltage Protection, 106, 289
P
Parallel Cabling
Guidelines, 135
Parasitic capacitance, 59
Parasitic inductance, 59
Partition panel
Partitioning the EMC domains in the
cabinet, 121
PAY safety module, 232
PE (Protective Earth), 41
Peak value, 56
PEN (Protective Earth Neutral), 41
Periodic interference, 53
Phase controller, 55
Point-to-point grounding system, 81
Power circuits, 50
Power connection, 43
Power converter, 50
Power Line
Switching off power lines, 72
Power Supplies
Selecting, 167
Power Supply, 117
Galvanic Coupling via the Power Supply,
66
Planning the Power Supply, 116
Single, Configuration, 168
Power supply
as a source of conducted disturbance, 51
Power Supply System
Structuring, 166
Precautions, 217
Precautions for use
Discrete I/Os, 221
Precautions for wiring PAY safety modules,
233
Process
Process as zone with interfering
components, 92
340
Process Signal
Analog Process Signal, Cable, 126
Process signal
Cable ducts in the cabinet, 126
Product liability, 26
Product Standard, 20
PROFIBUS DP
Capacitive By-Pass Terminal GND 001,
282
Grounding and Shielding for Systems
with Equipotential Bonding, 275
Grounding and Shielding for Systems
without Equipotential Bonding, 276
Installation, Wiring, 274
Static Discharge in Long Cables, 281
Surge Protection for Bus Leads (lightning
protection), 278
Protection Classes, 41
Protective Circuits
for AC Actuators, 171
for DC Actuators, 170
Protective Class 0, 41
Protective Class I, 41
Protective Class II, 41
Protective Class III, 41
Protective conductor, 43
Protective conductor connector, 43
Protective Earth, 42
Protective earth
for PLCs, 43
Protective earth connection, 43
Protective Grounding
Guidelines for Earthing and Grounding in
the Cabinet, 122
Pulse
Frequency spectrum of an interference
pulse, 56
R
Radar, 50
Radiated interference
Sources of radiated interference, 52
Radiating Coupling
Mechanism, Size, 75
Index
Radiation
Radiation hazards, 38
Radio Transmitter, 75
Radio transmitter, 50
Rate of change, 56
Receiver, 50
Reference Conductor System
Galvanic Coupling via Common
Reference Conductor System, 66
Reflection, 76
Regulations, 15
Harmonized Regulations and Standards
in the EU, 18
RF surgery, 52
Rise time, 56
RS422, 58
Rules for connecting to PSY supply
modules, 193
Rules for implementation, 239
S
S type Point-to-point grounding system, 81
Safety
Highest Safety Requirements, 96
Safety Equipment
According to the Machine Directive, 22
Safety extra-low voltage, 41
Secure partition between circuits, 39
Self inductance
Influence of line inductivity with galvanic
coupling, 67
SELV
Safety extra-low voltage, 41
Semiconductor-multiplexer, 52
Semi-conductors
Controller circuits with semi-conductors
as sources of interference, 51
Sensor cable
Sensor cable outside islands, 101
Sensors
Connection between sensors and
electronics, 58
Service, 42
Shielded Cable
Using Shielded Cables, 135
Shielding
All-around contact for the ground
connection, 124
Basics, 84
Cable shield ground connections, 138
Double shielding, 86
Driven shield, 86
of sensors and actuator cables outside of
islands, 101
Shields
How to create a ground connection for
cable shields, 113
Interference Current Dissipation of Cable
Shields, 126
Short Circuit, 69
Signal line
Cable ducts in the cabinet, 126
Signals
Classification of Signals according to
their EMC Performance, 132
Single Power Supply
Configuration, 168
Single wire, 58
Skin effect
Influence of the skin effect with galvanic
coupling, 67
Sound receiver, 50
Source of interference
Natural and technical sources of
interference, 50
Sources of radiated interference, 52
Sources of Interference
Classification, 50
Definition, 49
Sources of interference
Broad-band interference sources,
examples, 51
Examples of narrow-band sources of
interference, 50
Sources of conducted disturbance, 51
Standardization
Definition, 26
Standards, 15
Harmonized European Standards, 19
Harmonized Regulations and Standards
341
Index
in the EU, 18
International Standards, 27
Role of the Standards, 26
Selection of the Relevant Standards for
PLC System Users, 28
Static Electricity, 93
Steel cable duct, 142
Steel conduit
Cable duct, 142
Steel trays
Cable ducts, 142
Structuring
Power Supply System, 166
Suggested Component Values
for AC and DC Actuators, 172
Supply Network
Galvanic Coupling via the Power Supply,
66
Supply voltage
Supply voltage interference, 55
Surgery
Radio frequency surgery as a source of
radiated interference, 52
Susceptible Equipment
Definition, 49
Switching
inductivities, 72
Switching frequency, 59
Switching transistors, 61
Symmetrically operated circuit
with common mode interference, 60
with differential mode interference, 59
Symmetrically operated circuits, 58
System
Validity of the Machine Directive, 22
T
Telephone connection, 58
Television Transmitter, 75
Termination Resistance, 76
Thermostat contacts (arcing), 52
TN System, 36
TN-C System, 36
TN-C-S System, 36
TN-S System, 36
342
Transformer
Filtering the Mains Voltage, 117
Installing Transformers, 117
Isolation of Inductances through Partition
Panels in the Cabinet, 120
Transformer Coupling Inductive Coupling,
69
Transient, 54
Transmitter, 50
Radio and Television Transmitters, 75
Transmitter receiver, 50
Transmitter/Receiver, 75
Transposition, 83
Trunking
Cable duct, 142
TT System, 36
Tubular Fluorescent Lamps, 127
U
Ultrasonic device, 50
Unused Conductors
Guidelines for Grounding Unused
Conductors, 139
Useful Signals, 58
V
V.11, 58
Values
for AC and DC Actuators, 172
Valve
Isolation of Inductances through Partition
Panels in the Cabinet, 120
Voltage grading
Driven shield, 86
Voltage restriction, 39
W
Water Supply Line
Guidelines for Earthing and Grounding in
the Cabinet, 122
Wave Influence
Mechanism, Size, 76
Index
Wave lengths
Wave lengths of interference compared
with characteristic source and receiver
measurements, 64
Wave Resistance, 76
Weather, 52
Welding Current Generator, 69
Welding machine, 50
Wire cross section, 42
Wire Harness, 69
Wiring
Single wire, 58
Wiring techniques for balancing circuits,
83
Wiring arrangement, 83
Wiring precautions, 242, 248
Working clearance
Recommended working clearance
between cables, 135
343
Index
344
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