5
EMC Installation Guidelines
MITSUBISHI CNC
5 EMC Installation Guidelines
Refer to the "EMC Installation Guidelines BNP-B8582-45" for details related to the drive section (servo/ spindle drive unit).
5.1 Introduction
EMC Directives became mandatory as of January 1, 1996. The subject products must have a CE mark attached indicating that the product complies with the Directives.
As the NC unit is a component designed to control machine tools, it is believed that it is not a direct EMC
Directives subject. However, we would like to introduce the following measure plans to back up EMC
Directives compliance of the machine tool as the NC unit is a major component of the machine tools.
(1) Methods of installation in control/operation panel
(2) Methods of wiring cables to outside of panel
(3) Introduction of members for measures
Mitsubishi is carrying out tests to confirm the compliance to the EMC Directives under the environment described in this manual. However, the level of the noise will differ according to the equipment type and layout, control panel structure and wiring lead-in, etc.
Thus, we ask that the final noise level be confirmed by the machine manufacturer.
5.2 EMC Directives
The EMC Directives largely regulate the following two items.
- Emission Capacity to prevent output of obstructive noise that adversely affects external devices.
- Immunity Capacity to not malfunction due to obstructive noise from external source.
The details of each level are classified in the table below.
It is assumed that the Standards and test details required for a machine tool are the same as these.
Class
Emission
Name
Radiated noise
Immunity
Conductive noise
Static electricity electrical discharge
Radiation immunity
Burst immunity
Conductive immunity
Power supply frequency magnetic field
Power supply dip
(fluctuation)
Surge
Details
Restriction of electromagnetic noise radiated through the air
Restriction of electromagnetic noise discharged from power supply line
(Example) Regulation of withstand level of static electricity electrical discharge accumulated in human body
(Example) Simulation of immunity from digital wireless telephones
(Example) Regulation of withstand level of noise from relay or plug and play
(Example) Regulation of withstand level of noise flowed from power supply wires, etc.
(Example) Regulation of electromagnetic noise of
50/60Hz power supply frequency
(Example) Regulation of power voltage drop withstand level
(Example) Regulation of withstand level of noise caused by lightning
EN Standards
EN61000-6-4 (General industrial machine)
EN61800-3 (Motor control unit)
EN55011
(CLASS: A)
EN61000-4-2
EN61000-4-3
EN61000-6-2 (General industrial machine)
EN61800-3 (Motor control unit)
EN61000-4-4
EN61000-4-6
EN61000-4-8
EN61000-4-11
EN61000-4-5
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5.3 EMC Measures
5.3 EMC Measures
The main items relating to EMC measures include the following.
(1) Store the device in a sealed metal panel.
(2) Ground all conductors that are floating electrically. Decrease the impedance.
(3) Increase the distance between the drive line and signal wire.
(4) Shield the cables wired outside of the panel.
(5) Install a noise filter.
Take care to the following items to suppress the noise radiated outside of the panel.
(1) Accurately ground the devices.
(2) Use shielded cables.
(3) Increase the electrical seal of the panel. Reduce the gaps and holes.
5.4 Panel Structure
The design of the panel is a very important factor for the EMC measures, so take the following measures into consideration.
5.4.1 Measures for Control Panel Body
(1) Use metal for all members configuring the panel.
(2) When joining the metal plate, treat the welded or contacting sections so that the impedance is reduced, and then fix with screws.
Joining clearance:Approx. 20cm
Painting mask
(3) Note that if the plate warps due to the screw fixing, etc. By creating a clearance, noise could leak from that place.
(4) Plate (nickel tin) the metal plate surface at the grounding plate, and connect the connections with a low impedance.
(5) If there is a large opening, such as ventilation holes, make sure to close the hole.
Control panel
Mesh cover
(conductive sponge)
Opening
(Note 1) Using screws to fix the plates that have been painted is the same as an insulated state. Peel the paint and fix the screws.
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5 EMC Installation Guidelines
5.4.2 Measures for Door
(1) Use metal for all members configuring the panel.
(2) When joining the door, use a gasket to lower the impedance of the contacting sections, or use a structure with a large contact area as shown below.
(3) The EMI gasket or conductive packing must contact the metal surface uniformly and at the correct position.
(a) Use of gasket
Door
(b) Large contact area
Control panel
Door
Contact area
Control panel
Cross-section drawing
EMI gasket
(Note 1) When not using a gasket, ground the control panel grounding with a grounding wire to lower the door's impedance.
(Note 2) Using screws to fix the plates that have been painted (attachment of packing) is the same as an insulated state. Peel the paint and fix the screws.
5.4.3 Measures for Power Supply
(1) Shield the power supply section and insert a filter to prevent the noise from flowing in or out. Selection of the noise filter capacity will differ according to the drive unit and devices being used. Refer to the
"EMC Installation Guidelines" (BNP-B8582-45).
Device Device
Radiated noise
Conductive noise
Radiated noise
NF
Noise filter
Flow out
AC input
Conductive noise
Partition plate
NF
Noise filter
AC input
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(Note 1) The conductive noise can be suppressed by inserting a noise filter, but the radiated noise will flow out.
(Note 2) The conductive and radiated noise can both be suppressed by adding a partition plate to the noise filter.
70 Series Connection Manual
5.5 Measures for Wiring in Panel
5.5 Measures for Wiring in Panel
Cables act as antennas to propagate unnecessary noise, and thus must be appropriately shielded and treated.
The following measures must be sufficiently considered for the cables (SH21/G013/F012/FCUA-R211) that carry out high-speed communication.
5.5.1 Precautions for Wiring in Panel
(1) If the cables are led unnecessary in the panel, they will pick up noise. Pay attention to the device layout and wire length so that the wiring length is as short as possible.
Device Device Device Device Device Device
Noise
(2) Always connect the grounding wire to the FG terminal indicated on the device.
(3) Keep the distance between the drive line and detector cable to the drive section motor as far apart as possible when wiring.
(4) Do not lead the power supply wire around the panel without using a filter.
Device
Conductive noise
Radiated noise
Partition
NF plate
0QKUG
HKNVGT
Flow out
AC input
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5 EMC Installation Guidelines
5.5.2 Shield Treatment of Cables
Use shielded cables for the cables wired outside the panel.
Use a shield clamp within 10cm of the lead-out port from the panel. (Refer to "5.6.1 Shield Clamp Fitting".)
(1) DC power supply cable [F110/F070 cable]
Shield clamp
Operation panel
Display unit
Control panel
PD25
F110 cable
Operation panel
I/O unit
General-purpose stabilized power supply
F070 cable
Ferrite core
- Use a shield clamp within 10cm from the panel's inlet/outlet.
- Install a ferrite core on both ends of the connected units.
- Always install a ferrite core on the general-purpose stabilized power supply. (Refer to "5.6.2 Ferrite
Core".) The ferrite core may not be required depending on the selected power supply.
(2) Remote I/O cable [FCUA-R211 cable]
Shield clamp
Control panel
Control unit
FCUA-R211 cable
Control panel
Remote I/O unit
Ferrite core
Use a shield clamp within 10cm from the panel's inlet/outlet.
Install a ferrite core on both ends of the connected units.
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5.5 Measures for Wiring in Panel
(3) Servo communication cable [SH21 cable]
Shield clamp
Control panel
Control unit
SH21B cable
Control panel
Drive section unit
Ferrite core
Use a shield clamp within 10cm from the panel's inlet/outlet.
Install a ferrite core on both ends of the connected units.
(4) Ethernet cable
Shield clamp
Operation panel
Control unit
Control panel
Peripheral device
Ethernet cable
Ferrite core
- Use a shielded cable. Use a shield clamp within 10cm from the panel's inlet/outlet.
- Install a ferrite core on both ends of the connected units.
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5.6 EMC Countermeasure Parts
5.6.1 Shield Clamp Fitting
The effect can be improved by directly connecting the cable's shield sheath to the grounding plate as shown below.
Install the grounding plate near the outlet (within 10cm) of each panel, and press against the grounding plate with the clamp fitting.
If the cables are thin, several can be bundled and clamped together.
To provide sufficient frame ground, install the grounding plate directly on the cabinet or connect with a grounding wire.
AERSBAN-DSET
AERSBAN-ESET
A
100
70
86
56
B
30
C
-
Enclosed fittings
Clamp fitting A × 2
Clamp fitting B × 1
Clamp fitting A
Clamp fitting B
70
45
L
Peel the cable sheath at the clamp section.
Cable
Earthing plate
Cable
Clamp fitting
(Fitting A, B)
Shield sheath
Outline drawing
Earthing plate
2Ǿ 5 hole
Installation hole
17.5
View of clamp section
Clamp fitting
0QVG
M4 screw
6 22
35
MAX L 10
.3 0
[Unit: mm]
(Note 1) Screw hole for wiring to earthing plate in cabinet.
(Note 2) The earthing plate thickness is 1.6mm.
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5.6 EMC Countermeasure Parts
5.6.2 Ferrite Core
The ferrite core is mounted integrally with the plastic case.
This can be installed with one touch without cutting the interface cable or power supply cable.
This ferrite core is effective against common mode noise, allowing measures against noise without affecting the quality of the signal.
Shape and dimensions
ZCAT type
ZCAT-A, ZCAT-AP type ZCAT-B type
ZCAT-C type
ZCAT-D type
Recommended ferrite core: TDK ZCAT Series
Part Name
ZCAT1518-0730-M(-BK)*1
ZCAT1518-0730(BK)*2
ZCAT2017-0930-M(-BK)
ZCAT2032-0930-M(-BK)*1
ZCAT2032-0930(-BK)*2
ZCAT2132-1130-M(-BK)*1
ZCAT2132-1130(-BK)*2
ZCAT3035-1330-M(-BK)*1
ZCAT3035-1330(-BK)*2
ZCAT1525-0430AP-M(-BK)
ZCAT1325-0530A-M(-BK)*1
ZCAT1325-0530A(-BK)
ZCAT1730-0730A-M(-BK)
ZCAT2035-0930A-M(-BK)*1
ZCAT2035-0930A(-BK)
ZCAT2235-1030A-M(-BK)
ZCAT2436-1330A-M(-BK)
ZCAT2017-0930B-M(-BK)
ZCAT2749-0430C-M(-BK)
ZCAT4625-3430D(-BK)
ZCAT4625-3430DT(-BK)*3
ZCAT6819-5230D(-BK)
ZCAT6819-5230DT(-BK)*3
A
39±1
39±1
25±1
25±1
25±1
30±1
35±1
35±1
22±1
22±1
21±1
36±1
36±1
36±1
36±1
B
18±1
18±1
17±1
32±1
32±1
32±1
32±1
34±1
34±1
20±1
20±1
20±1
23±1
28±1
28±1
øC
7±1
7±1
9±1
9±1
9±1
11±1
11±1
13±1
13±1
4±1
5±1
5±1
7±1
9±1
9±1
øD
–
–
–
E
Applicable cable outer diameter
7max.
15±1
15±1
20±1
19.5±1 –
19.5±1 –
20.5±1 –
20.5±1 –
30±1
30±1
–
–
7max.
9max.
9max.
9max.
11max.
11max.
13max.
13max.
15±1 11.5±1 2.5 to 4(USB)
12.8±1 11.2±1 3 to 5(USB)
12.8±1 11.2±1 3 to 5(USB)
16.5±1 15±1 4 to 7(USB)
19.5±1 17.4±1 6 to 9
19.5±1 17.4±1 6 to 9
35±1
36±1
21±1
49±1
28±1
29±1
17±1
27±1
10±1
13±1
21.5±1 20±1
23.5±1 22±1
8 to 10
10 to 13
9±1 20±1 28.5±1 9max.
4.5±1 19.5±1 – 4.5max.
45.5±1 24.5±1 34±1
45.5±1 24.5±1 34±1
67.5±1 18.5±1 52±1
67.5±1 18.5±1 52±1
12±1
13±1
16±1
17±1
–
–
–
–
26 For core flat cable
26 For core flat cable
40 For core flat cable
40 For core flat cable
Unit: mm
Mass (g)
7
12
22
22
7
7
63
63
22
22
22
22
6
6
11
32
32
58
58
27
29
12
26
*1 The M stamp is attached.
*2 A fixing band is attached at shipment.
*3 The core is fixed with double-sided tape. (The tape is enclosed with the part.)
● ZCAT-B type: Cabinet fixing type installation hole ø4.8 to 4.9mm, plate thickness 0.5 to 2mm
● ZCAT-AP, ZCAT-C type: Structure that prevents easy opening after case is closed.
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5.6.3 Surge Absorber
Make sure that the surge does not directly enter the AC line of the general-purpose stabilized power supply
(user-prepared) supplying power to the control unit and DIO. Select the following product or equivalent for the surge absorber. Refer to the manufacturer catalog for detailed characteristics, outline and connection methods of the surge absorber.
(1) Part name: RAV-781BYZ-2
Manufacturer: OKAYA ELECTRIC INDUSTRIES
Circuit voltage
50/60Hz Vrms
Max. tolerable circuit voltage
Clamp voltage
V±10%
250V 3 φ 300V 783V
Surge withstand level 8/
20 μ s
2,500A
Surge electrical discharge start voltage 1.2/
50 μ s
20kV
Static capacity
75pF
Working temperature range
-20 to +70C°
Outline drawing Circuit drawing
(a) Black (b) Black (c) Black
UL-1015 AWG16
41 ± 1
Unit 㧦 mm
(2) Part name: RAV-781BXZ-4
Manufacturer: OKAYA ELECTRIC INDUSTRIES
Circuit voltage
50/60Hz Vrms
Max. tolerable circuit voltage
Clamp voltage
V±10%
250V 3 φ 300V 700V
Surge withstand level 8/
20 μ s
2,500A
Surge electrical discharge start voltage 1.2/
50 μ s
2kV
Static capacity
75pF
Working temperature range
-20 to +70C°
Outline drawing Circuit drawing
(a) Black (b) Black (c) Black Green
UL-1015 AWG16
41 ± 1
Unit : mm
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5.6 EMC Countermeasure Parts
(3) Example of surge absorber installation
An example of installing the surge absorber in the machine control panel is shown below.
A short-circuit fault will occur in the surge absorber if a surge exceeding the tolerance is applied. Thus, install a circuit protection breaker in the stage before the surge absorber. Note that almost no current flows to the surge absorber during normal use, so a breaker installed as the circuit protection for another device can be used for the surge absorber.
Transformer Circuit breaker
NC control section
Other devices
(panel power supply, etc.)
From power supply
200VAC
/230VAC input
Panel leakage breaker
Circuit breaker
A
MC
B
Reactor
NC drive section
Control panel
(relay panel, etc.)
Other devices
(panel power supply, etc.)
Circuit protector
Surge absorber (a)
C
Surge absorber (b)
Ground
Grounding plate Example of surge absorber installation
Surge absorber installation
CAUTION
1. The wires from the surge absorber should be connected without extensions.
2. If the surge absorber cannot be installed just with the enclosed wires, keep the wiring length of A and B to 2m or less. If the wires are long, the surge absorber's performance may drop and inhibit protection of the devices in the panel.
3. Surge absorber to be selected varies depending on input power voltage.
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5.6.4 Selection of Stabilized Power Supply
Consider the following characteristics when selecting the stabilized power supply (prepared by machine manufacturer).
Use a power supply that complies with CE Marking or that follows the safety standards given below.
Stabilized power supply selection items
Remarks
±5% or less of 24VDC output
Output
Voltage fluctuation ±5%
Ripple noise
Spike noise
120mV (max.)
500mV (max.)
Output current
Output holding time
――
20ms (min)
Refer to the maximum current consumption of the unit in use and calculate.
Instantaneous power failure time (AC side)
Standards
Safety Standards: UL1950, CSA C22.2 No. 234 approved, IEC950 compliant
Noise Terminal Voltage: FCC Class A, VCCI-Class A
High Harmonics Current Restrictions: IEC61000-3-2
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