Bulletin 150 SMC-Flex™ Application Guide

Bulletin 150 SMC-Flex™ Application Guide

SMC-Flex™

Bulletin 150 SMC-Flex™

Application Guide

Bulletin 150 SMC-Flex™ ii

Important User

Information

Because of the variety of uses for the product described in this publication, those responsible for the application and use of this control equipment must satisfy themselves that all necessary steps have been taken to assure that each application and use meets all performance and safety requirements, including any applicable laws, regulations, codes and standards.

The illustrations, charts, sample programs and layout examples shown in this guide are intended solely for purposes of example. Since there are many variables and requirements associated with any particular installation, Rockwell Automation does not assume responsibility or liability (to include intellectual property liability) for actual use based upon the examples shown in this publication.

Rockwell Automation publication SGI-1.1, Safety Guidelines for the Application, Installation and Maintenance of Solid-State Control (available from your local Allen-Bradley distributor), describes some important differences between solid-state equipment and electromechanical devices that should be taken into consideration when applying products such as those described in this publication.

Reproduction of the contents of this copyrighted publication, in whole or part, without written permission of Rockwell Automation, is prohibited.

Throughout this manual we use notes to make you aware of safety considerations:

!

ATTENTION: Identifies information about practices or circumstances that can lead to personal injury or death, property damage or economic loss

Attention statements help you to:

• identify a hazard

• avoid a hazard

• recognize the consequences

IMPORTANT

Important: Identifies information that is critical for successful application and understanding of the product.

Trademark List

Accu-Stop, Allen-Bradley Remote I/O, SMC, SMC-2, SMC-Flex, SMC PLUS, SMC Dialog Plus, SMB, and STC are trademarks of

Rockwell Automation. ControlNet is a trademark of ControlNet International, Ltd. DeviceNet and the DeviceNet logo are trademarks of the Open Device Vendors Association (ODVA). Ethernet is a registered trademark of Digital Equipment Corporation,

Intel, and Xerox Corporation.

Bulletin 150 SMC-Flex™

Chapter 1

Overview

Chapter 2

Application Profiles for the SMC-Flex

Controller

Table of Contents

Introduction ................................................................................... 1-1

SMC-Flex Features ................................................................. 1-1

Description .................................................................................... 1-2

Modes of Operation ....................................................................... 1-2

Standard ....................................................................................... 1-3

Soft Start with Selectable Kickstart ......................................... 1-3

Current Limit Start with Selectable Kickstart ........................... 1-6

Dual Ramp Start with Selectable Kickstart .............................. 1-9

Full Voltage Start .................................................................. 1-12

Preset Slow Speed ................................................................ 1-15

Linear Speed Acceleration with Selectable Kickstart ............. 1-18

Soft Stop .............................................................................. 1-21

Pump Control .............................................................................. 1-24

Pump Control Option with Selectable Kickstart ...................... 1-24

Braking Control ............................................................................ 1-27

SMB Smart Motor Braking Option ......................................... 1-27

Accu-Stop ............................................................................ 1-30

Slow Speed with Braking ...................................................... 1-33

Features ...................................................................................... 1-36

SCR Bypass .......................................................................... 1-36

Standard or Wye-Delta Wiring ............................................... 1-36

LCD Display .......................................................................... 1-36

Parameter Programming ....................................................... 1-36

Electronic Overload ............................................................... 1-37

Stall Protection and Jam Detection ....................................... 1-37

Ground Fault Protection ........................................................ 1-38

Thermistor Input ................................................................... 1-38

Metering ............................................................................... 1-38

Fault Indication ..................................................................... 1-39

Parameter Programming ............................................................. 1-40

Communication Capabilities .................................................. 1-40

Auxiliary Contacts ................................................................. 1-40

Modular Design .................................................................... 1-40

Control Terminal Description ................................................. 1-41

Overview ....................................................................................... 2-1

iii

iii

Bulletin 150 SMC-Flex™

Chapter 3

Special Application Considerations

Chapter 4

Product Line Applications Matrix

Chapter 5

Design Philosophy

Chapter 6

Reduced Voltage Starting

iv

SMC-Flex Controllers in Drive Applications .....................................3-1

Use of Protective Modules .......................................................3-1

Motor Overload Protection ..............................................................3-2

Stall Protection and Jam Detection .................................................3-2

Built-in Communication ..................................................................3-3

Power Factor Capacitors ................................................................3-3

Multi-motor Applications ................................................................3-5

Special Motors ...............................................................................3-6

Wye-Delta ...............................................................................3-6

Part Winding ............................................................................3-7

Wound Rotor ...........................................................................3-7

Synchronous ...........................................................................3-7

Altitude De-rating ...........................................................................3-7

Isolation Contactor .........................................................................3-8

SMC-Flex Controller with Bypass Contactor (BC) ............................3-9

SMC-Flex Controller with Reversing Contactor ..............................3-10

SMC-Flex Controller as a Bypass to an AC Drive ...........................3-11

SMC-Flex Controller with a Bulletin 1410 Motor Winding Heater ...3-12

Motor Torque Capabilities with SMC-Flex Controller Options .........3-13

SMB Smart Motor Braking .....................................................3-13

Preset Slow Speed ................................................................3-13

Accu-Stop .............................................................................3-14

Description .....................................................................................4-1

Mining and Metals ..........................................................................4-1

Food Processing .............................................................................4-2

Pulp and Paper ...............................................................................4-2

Petrochemical ................................................................................4-3

Transportation and Machine Tool ...................................................4-3

OEM Specialty Machine ..................................................................4-4

Lumber and Wood Products ...........................................................4-4

Water/Wastewater Treatment and Municipalities ............................4-4

Philosophy .....................................................................................5-1

Line Voltage Conditions ..................................................................5-1

Current and Thermal Ratings ..........................................................5-1

Mechanical Shock and Vibration .....................................................5-1

Noise and RF Immunity ..................................................................5-1

Altitude ..........................................................................................5-2

Pollution .........................................................................................5-2

Setup .............................................................................................5-2

Introduction to Reduced Voltage Starting ........................................6-1

Reduced Voltage ............................................................................6-2

Chapter 7

Solid-State Starters Using SCRs

Chapter 8

Reference

Bulletin 150 SMC-Flex™

Solid-State .................................................................................... 6-4

Notes ............................................................................................ 6-6

..................................................................................................... 7-1

Motor Output Speed/Torque/Horsepower ....................................... 8-1

Torque and Horsepower ................................................................ 8-2

Motor Output for NEMA Design Designations Polyphase

1…500 Hp .......................................................................... 8-7

Calculating Torque (Acceleration Torque Required for

Rotating Motion) .................................................................. 8-9

Inertia ................................................................................... 8-10

Torque Formulas .................................................................. 8-10

AC Motor Formulas ............................................................... 8-11

Torque Characteristics on Common Applications ................... 8-12

Electrical Formulas ................................................................ 8-14

Calculating Motor Amperes.................................................... 8-15

Other Formulas...................................................................... 8-15

v

v

vi

Bulletin 150 SMC-Flex™

Chapter 1

Overview

List of Figures

Figure 1.1: SMC-Flex Controller ...................................................1-2

Figure 1.2: Soft Start ...................................................................1-3

Figure 1.3: Soft Start Sequence of Operation ...............................1-4

Figure 1.4: Soft Start Wiring Diagram ..........................................1-5

Figure 1.5: Current Limit Start .....................................................1-6

Figure 1.6: Current Limit Sequence of Operation .........................1-7

Figure 1.7: Current Limit Wiring Diagram ....................................1-8

Figure 1.8: Dual Ramp Start ........................................................1-9

Figure 1.9: Dual Ramp Start Sequence of Operation ..................1-10

Figure 1.10: Dual Ramp Start Wiring Diagram .............................1-11

Figure 1.11: Full Voltage Start .....................................................1-12

Figure 1.12: Full Voltage Start Sequence of Operation .................1-13

Figure 1.13: Full Voltage Start Wiring Diagram ............................1-14

Figure 1.14: Preset Slow Speed ..................................................1-15

Figure 1.15: Preset Slow Speed Sequence of Operation ..............1-16

Figure 1.16: Preset Slow Speed Wiring Diagram ..........................1-17

Figure 1.17: Linear Speed Acceleration .......................................1-18

Figure 1.18: Linear Speed Acceleration Sequence of Operation ...1-19

Figure 1.19: Linear Speed Acceleration Wiring Diagram ..............1-20

Figure 1.20: Soft Stop .................................................................1-21

Figure 1.21: Soft Stop Sequence of Operation .............................1-22

Figure 1.22: Soft Stop Wiring Diagram ........................................1-23

Figure 1.23: Pump Control Option with Selectable Kickstart .........1-24

Figure 1.24: Pump Control Option Sequence of Operation ............1-25

Figure 1.25: Pump Control Option Wiring Diagram .......................1-26

Figure 1.26: Smart Motor Braking ...............................................1-27

Figure 1.27: Smart Motor Braking Sequence of Operation ...........1-28

Figure 1.28: Smart Motor Braking Wiring Diagram ......................1-29

Figure 1.29: Accu-Stop ...............................................................1-30

Figure 1.30: Accu-Stop Sequence of Operation ...........................1-31

Figure 1.31: Accu-Stop Wiring Diagram .......................................1-32

Figure 1.32: Slow Speed with Braking .........................................1-33

Figure 1.33: Slow Speed with Braking Sequence of Operation .....1-34

Figure 1.34: Slow Speed with Braking Wiring Diagram ................1-35

Figure 1.35: LCD Display with Keypad .........................................1-36

Figure 1.36: Stall Protection Sequence of Operation ....................1-37

Figure 1.37: Jam Detection Sequence of Operation .....................1-38

Figure 1.38: Exploded View .........................................................1-40

Figure 1.39: SMC-Flex Controller Control Terminals ....................1-42

Bulletin 150 SMC-Flex™

Chapter 2

Application Profiles for the SMC-Flex

Controller

Chapter 3

Special Application Considerations

Chapter 6

Reduced Voltage Starting

Figure 2.1: Compressor with Soft Start ....................................... 2-1

Figure 2.2: Tumbler with Soft Start and Accu-Stop .................... 2-2

Figure 2.3: Pump with Soft Start ................................................. 2-3

Figure 2.4: Bandsaw with Soft Start and Slow Speed with Braking ..

2-4

Figure 2.5: Rock Crusher with Soft Start ..................................... 2-5

Figure 2.6: Hammermill with Current Limit Start and SMB Smart Motor Braking 2-6

Figure 2.7: Centrifuge with Current Limit Start and SMB Smart Motor

Braking 2-7

Figure 2.8: Wire Draw Steel Mill Machine with Soft Start ............ 2-8

Figure 2.9: Overload conveyor with Linear Speed and Tack Feedback

2-9

Figure 2.10: Ball Mill with Current Limit Start ............................. 2-10

Figure 3.1: Protective Module ..................................................... 3-1

Figure 3.2: Power Factor Capacitors ........................................... 3-3

Figure 3.3: Power Factor Capacitors with Isolation Contactor ...... 3-4

Figure 3.4: Multi-Motor Application ............................................. 3-5

Figure 3.5: Inside-the-Delta Wiring. ............................................ 3-6

Figure 3.6: Typical Connection Diagram with Isolation Contactor 3-8

Figure 3.7: Typical Application Diagram of a Bypass Contactor ... 3-9

Figure 3.8: Typical Application with a Single-Speed Reversing Starter

3-10

Figure 3.9: Typical Application Diagram of a Bypass Contactor for an

AC Drive 3-11

Figure 3.10: Typical Application Diagram of SMC-Flex Controller with a

Bulletin 1410 Motor Winding Heater 3-12

Figure 3.11: Starting and Running Torque ................................... 3-13

Figure 3.12: Accu-Stop Option .................................................... 3-14

Figure 6.1: Full-Load Current vs. Speed ...................................... 6-1

Figure 6.2: Bulletin 570 Autotransformer .................................... 6-2

Figure 6.3: Open Circuit Transition .............................................. 6-3

Figure 6.4: Closed Circuit Transition ........................................... 6-3

Figure 6.5: Transition at Low Speed ............................................ 6-3

Figure 6.6: Transition near Full Speed ........................................ 6-3

Figure 6.7: SMC-Flex Solid-State Controllers .............................. 6-4

Figure 6.8: Soft Start .................................................................. 6-5

Figure 6.9: Current Limit Start .................................................... 6-5

vii

vii

Bulletin 150 SMC-Flex™

Chapter 7

Solid-State Starters Using SCRs

Chapter 8

Reference

Figure 7.1: Silicon Controlled Rectifier (SCR) ...............................7-1

Figure 7.2: Typical Wiring Diagram for SCRs ...............................7-1

Figure 7.3: Different Firing Angles (Single-Phase Simplification) ..7-2

Figure 8.1: Shaft and Wrench ......................................................8-2

Figure 8.2: Speed-Torque Curve ..................................................8-3

Figure 8.3: Speed-Torque Curve with Current Curve ....................8-4

Figure 8.4: Motor Safe Time vs. Line Current — Standard Induction

Motors 8-6

Figure 8.5: Typical NEMA Design A Speed/Torque Curve .............8-7

Figure 8.6: Typical NEMA Design B Speed/Torque Curve .............8-7

Figure 8.7: Typical NEMA Design C Speed/Torque Curve .............8-8

Figure 8.8: Typical NEMA Design D Speed/Torque Curve .............8-8

viii

Bulletin 150 SMC Flex™

Introduction

Chapter

1

Overview

The Allen-Bradley SMC Controller lines offer a broad range of products for starting or stopping

AC induction motors from ½ Hp to 6000 Hp. The innovative features, compact design, and available enclosed controllers meet world-wide industry requirements for controlling motors.

Whether you need to control a single motor or an integrated automation system, our range of controllers meet your required needs.

This document discusses the SMC-Flex™. Some of the key features are listed below.

SMC-Flex Features

• Soft Start — with Selectable Kickstart

Current Limit Start — with Selectable Kickstart

• Dual Ramp — with Selectable Kickstart

Full Voltage

• Linear Speed Acceleration — with Selectable Kickstart

Preset Slow Speed

• Soft Stop

Pump Control — with Selectable Kickstart

• SMB™ Smart Motor Braking

Accu-Stop™

• Slow Speed with Braking

Built in Bypass

• Inside the Delta

Electronic Motor Overload Protection

• Stall and Jam Detection

Ground Fault Protection

• Thermistor Input (PTC)

Metering

• Fault Indication

Parameter Programming

• Communication Capabilities

1-1

Bulletin 150 SMC Flex™

Description

Modes of

Operation

When the Smart Motor Controller (SMC™) was first introduced in 1986, its modular design, digital setup, and microprocessor control set the standard for soft starters. Since its launch in

1996, the SMC Dialog Plus™ controller has been in a class by itself, providing unmatched performance with innovative starting and stopping options. Now, the SMC-Flex controller achieves a higher level of sophistication with greatly enhanced protection, expanded diagnostics, ability to log the motor’s operation (A, kW, and power factor), and flexibility to communicate with various network protocols. The SMC-Flex can also be wired in a standard wiring configuration, or inside-the-delta. This allows the product to operate wye-delta motors with a much smaller device than before.

Figure 1.1:SMC-Flex Controller

The SMC-Flex controller is a compact, modular, multi-functional solid-state controller used in both starting three-phase squirrel-cage induction motors or wye-delta motors and controlling resistive loads.

The SMC-Flex contains, as standard, a built-in SCR bypass and a built-in overload. The SMC-Flex product line includes current ratings

5 to 480 A, 200 to 600V, 50/60Hz. This covers squirrel-cage induction motor applications up to 400 Hp (wye-delta motors up to 650 Hp). The

SMC-Flex controller meets applicable standards and requirements.

While the SMC-Flex controller incorporates many new features into its design, it remains easy to set up and operate. You can make use of as few or as many of the features as your application requires.

The following modes of operation are standard within a single controller:

Standard:

• Soft Start with Selectable Kickstart

Current Limit with Selectable Kickstart

• Dual Ramp Start with Selectable Kickstart

• Full Voltage Start

• Preset Slow Speed

Linear Speed Acceleration with Selectable Kickstart

• Soft Stop

Pump Option

Pump Control with Selectable Kickstart

Braking Option

• Smart Motor Braking

Accu-Stop

• Slow Speed with Braking

1-2

Standard

Bulletin 150 SMC Flex™

Soft Start with Selectable Kickstart

This method covers the most general applications. The motor is given an initial torque setting, which is user adjustable from 0 to 90% of locked rotor torque. From the initial torque level, the output voltage to the motor is steplessly increased during the acceleration ramp time, which is user adjustable from 0 to 30 seconds. If, during the voltage ramp operation, the SMC-Flex controller senses that the motor has reached an up-to-speed condition, the output voltage will automatically switch to full voltage, and transition over the SCR Bypass contactors.

The kickstart feature provides a boost at startup to break away loads that may require a pulse of high torque to get started. It is intended to provide a current pulse, user adjustable 0-90% locked rotor torque for a selected period of time from 0.0 to 2.0 seconds.

Figure 1.2: Soft Start

Percent

Voltage

100%

Initial

Torque

Start Run

Time (seconds)

Following are the parameters that are specifically used to provide and adjust the voltage ramp supplied to the motor.

Table 1.A: Soft Start Parameters

Parameter

SMC Option

Starting Mode

Ramp Time

Initial Torque

Kickstart Time

Kickstart Level

Option 2 Input

Stop Mode

Stop Time

Standard, Braking, Pump

Soft Start

0…30 s

0…90% LRT

0.0…2.0 s

0…90% LRT

Disable

Disable

0 s

Adjustment

1-3

1-4

Bulletin 150 SMC Flex™

Figure 1.3: Soft Start Sequence of Operation

Selectable Kickstart

100%

Percent

Voltage

Start Run

Time (seconds)

Push Buttons

Start

Closed

Open

Stop

Soft Stop

Closed

Open

Closed

Open

Auxiliary Contacts

Normal

Closed

Open

Up-to-speed

Closed

Open

Coast-to-rest

Soft Stop

Soft Stop

If Soft Stop Selected

If Coast-to-rest Selected

Bulletin 150 SMC Flex™

Figure 1.4: Soft Start Wiring Diagram

Control Power

Stop

Start

11 12 13 14 15 16 17 18 19 20 21 22

SMC-Flex

Control Terminals Aux #1

Normal/Up-to-Speed/

Bypass

23 24 25 26 27 28 29 30 31 32 33 34

PTC

Input

TACH

Input

Ground

Fault

Fault

Contact

Alarm

Contact

Aux #2

Normal

Customer supplied.

Refer to the controller nameplate to verify the rating of the control power input rating.

Internal

Auxilary

Contacts

1-5

1-6

Bulletin 150 SMC Flex™

Current Limit Start with Selectable Kickstart

This method provides a current limit start and is used when it is necessary to limit the maximum starting current. The starting current is user adjustable from 50 to 600% of full load amperes.

The current limit ramp time is user adjustable from 0 to 30 seconds.

The kickstart feature provides a boost at startup to break away loads that may require a pulse of high torque to get started. It is intended to provide a current pulse, user adjustable 0-90% locked rotor torque for a selected period of time from 0.0 to 2.0 seconds.

Figure 1.5: Current Limit Start

600%

Percent Full

Load Current

50%

Start

Time (seconds)

To apply a current limit output to the motor, the following parameters are provided for user adjustment.

Table 1.B: Current Limit Start Parameters

Parameter

SMC Option

Starting Mode

Ramp Time

Current Limit Level

Kickstart Time

Kickstart Level

Option 2 Input

Stop Mode

Stop Time

Standard, Braking, Pump

Current Limit

0…30 s

50…600% FLC

0.0…2.0 s

0…90% LRT

Disable

Disable

0 s

Adjustments

Bulletin 150 SMC Flex™

Figure 1.6: Current Limit Sequence of Operation

600%

Percent Full

Load

Current

100%

50%

Start Run

Time (seconds)

Push Buttons

Start

Closed

Open

Stop

Soft Stop

Closed

Open

Closed

Open

Auxiliary Contacts

Normal

Closed

Open

Up-to-speed

Closed

Open

Coast-to-rest

Soft Stop

Soft Stop

If Soft Stop Selected

If Coast-to-rest Selected

1-7

1-8

Bulletin 150 SMC Flex™

Figure 1.7: Current Limit Wiring Diagram

Control Power

Stop

Start

11 12 13 14 15 16 17 18 19 20 21 22

SMC-Flex

Control Terminals Aux #1

Normal/Up-to-Speed/

Bypass

23 24 25 26 27 28 29 30 31 32 33 34

PTC

Input

TACH

Input

Ground

Fault

Fault

Contact

Alarm

Contact

Aux #2

Normal

Customer supplied.

Refer to the controller nameplate to verify the rating of the control power input rating.

Internal

Auxilary

Contacts

Bulletin 150 SMC Flex™

Dual Ramp Start with Selectable Kickstart

This starting method is useful on applications with varying loads, starting torque, and start time requirements. Dual Ramp Start offers the user the ability to select between two separate Start profiles with separately adjustable ramp times and initial torque settings.

The kickstart feature provides a boost at startup to break away loads that may require a pulse of high torque to get started. It is intended to provide a current pulse, user adjustable 0…90% locked rotor torque for a selected period of time from 0.0 to 2.0 seconds.

Figure 1.8: Dual Ramp Start

Percent

Voltage

Ramp #2

100%

Initial Torque

#2

Initial Torque

#1

Ramp #1

Start #1

Start #2

Time (seconds)

Run #1

Run #2

To obtain Dual Ramp Start control, the following parameters are available when you select Dual

Ramp in the Option 2 Input parameter.

Table 1.C: Dual Ramp Start Parameters

Parameter

SMC Option

Starting Mode

Ramp Time

Initial Torque

Current Limit Level

Torque Limit

Kickstart Time

Kickstart Level

Option 2 Input

Starting Mode 2

Start Time 2

Initial Torque 2

Current Limit Level 2

Torque Limit 2

Kickstart Time 2

Kickstart Level 2

Stop Mode

Stop Time

Adjustments

Standard

Full Voltage, Current Limit, Soft Start, Linear Speed

0…30 s

0…90% LRT

50…600% FLC

0…100% LRT

0.0…2.0 s

0…90% LRT

Dual Ramp

Full Voltage, Current Limit, Soft Start, Linear Speed

0…30 s

0…90% LRT

50…600% FLC

0…100% LRT

0.0…2.0 s

0…90% LRT

Disable

0 s

1-9

Bulletin 150 SMC Flex™

Figure 1.9: Dual Ramp Start Sequence of Operation

Ramp #2

Percent

Voltage

Ramp #1

Coast-to-rest

Soft Stop

Push Buttons

Start

Closed

Open

Stop

Soft Stop

Closed

Open

Closed

Open

Auxiliary Contacts

Normal

Closed

Open

Up-to-speed

Closed

Open

Start #1

Start #22 Run #2

Time (seconds)

Soft Stop

If Soft Stop Selected

If Coast-to-rest Selected

1-10

Bulletin 150 SMC Flex™

Figure 1.10: Dual Ramp Start Wiring Diagram

Control Power

Stop

Ramp 1 Ramp 2

Start

11 12 13 14 15 16 17 18 19 20 21 22

SMC-Flex

Control Terminals Aux #1

Normal/Up-to-Speed/

Bypass

23 24 25 26 27 28 29 30 31 32 33 34

PTC

Input

TACH

Input

Ground

Fault

Fault

Contact

Alarm

Contact

Aux #2

Normal

Customer supplied.

Refer to the controller nameplate to verify the rating of the control power input rating.

Internal

Auxilary

Contacts

1-11

Bulletin 150 SMC Flex™

Full Voltage Start

This method is used in applications requiring across-the-line starting. The SMC-Flex controller performs like a solid-state contactor. Full inrush current and locked rotor torque are realized.

The SMC-Flex may be programmed to provide full voltage start in which the output voltage to the motor reaches full voltage in ¼ second.

Figure 1.11: Full Voltage Start

100%

Percent

Voltage

Time (seconds)

The basic parameter setup for Full Voltage Start follows:

Table 1.D: Full Voltage Start Parameters

Parameter

SMC Option

Starting Mode

Stop Mode

Stop Time

Standard, Braking, Pump

Full Voltage

Disable

0 s

Adjustments

1-12

Bulletin 150 SMC Flex™

Figure 1.12: Full Voltage Start Sequence of Operation

100%

Percent

Voltage

Start Run

Time (seconds)

Push Buttons

Start

Closed

Open

Stop

Soft Stop

Closed

Open

Closed

Open

Auxiliary Contacts

Normal

Closed

Open

Up-to-speed

Closed

Open

Coast-to-rest

Soft Stop

Soft Stop

If Soft Stop Selected

If Coast-to-rest Selected

1-13

Bulletin 150 SMC Flex™

Figure 1.13: Full Voltage Start Wiring Diagram

Control Power

Stop

Start

11 12 13 14 15 16 17 18 19 20 21 22

SMC-Flex

Control Terminals Aux #1

Normal/Up-to-Speed/

Bypass

23 24 25 26 27 28 29 30 31 32 33 34

PTC

Input

TACH

Input

Ground

Fault

Fault

Contact

Alarm

Contact

Aux #2

Normal

Customer supplied.

Refer to the controller nameplate to verify the rating of the control power input rating.

Internal

Auxilary

Contacts

1-14

Bulletin 150 SMC Flex™

Preset Slow Speed

This method can be used on applications that require a slow speed for positioning material. The

Preset Slow Speed can be set for either Low, 7% of base speed, or High, 15% of base speed.

Reversing is also possible through programming. Speeds provided during reverse operation are

Low, 10% of base speed, or High, 20% of base speed.

Figure 1.14: Preset Slow Speed

100%

Motor

Speed

Forward

15% - High

7% - Low

10% - Low

20% - High

Time (seconds)

Reverse

Start Run

The basic parameter setup for Soft Start selection with Preset Slow Speed Option follows:

Table 1.E: Preset Slow Speed Parameters

Parameter

SMC Option

Starting Mode

Ramp Time

Initial Torque

Current Limit Level

Torque Limit

Kickstart Time

Kickstart Level

Option 2 Input

Stop Mode

Stop Time

Slow Speed Sel

Slow Speed Dir

Slow Accel Cur

Slow Running Cur

Adjustments

Standard, Braking

Full Voltage, Current Limit, Soft Start, Linear Speed

0…30 s

0…90% LRT

50…600% FLC

0…100% LRT

0.0…2.0 s

0…90% LRT

Preset SS

Disable

0 s

SS Low, SS High

SS Forward, SS Reverse

0…450% FLC

0…450% FLC

1-15

Bulletin 150 SMC Flex™

Figure 1.15: Preset Slow Speed Sequence of Operation

100%

Motor

Speed

7 or 15%

Start Run

Time (seconds)

Push Buttons

Start

Stop

Slow Speed

Closed

Open

Closed

Open

Closed

Open

Auxiliary Contacts

Normal

Closed

Open

Up-to-speed

Closed

Open

Slow Speed Coast

Coast-to-rest

Soft Stop

1-16

Bulletin 150 SMC Flex™

Figure 1.16: Preset Slow Speed Wiring Diagram

Control Power

Stop

Slow Speed

Start

11 12 13 14 15 16 17 18 19 20 21 22

SMC-Flex

Control Terminals

Aux #1

Normal/Up-to-Speed/

Bypass

23 24 25 26 27 28 29 30 31 32 33 34

PTC

Input

TACH

Input

Ground

Fault

Fault

Contact

Alarm

Contact

Aux #2

Normal

Customer supplied.

Refer to the controller nameplate to verify the rating of the control power input rating.

Internal

Auxilary

Contacts

1-17

Bulletin 150 SMC Flex™

Linear Speed Acceleration with Selectable Kickstart

This method starts the motor following a linear speed ramp. The ramp time defines the time the motor will ramp from zero speed to full speed. This ramp time is user adjustable from

0…30 seconds. Linear Speed requires a tachometer input (0…5 V DC, 4.5 V = 100% speed).

The curent limit is active during the starting ramp.

The kickstart feature provides a boost at startup to break away loads that may require a pulse of high torque to get started. It is intended to provide a current pulse, user adjustable 0…90% locked rotor torque for a selected period of time, 0.0…2.0 seconds. Note that speed ramp begins once the kickstart is completed.

Figure 1.17: Linear Speed Acceleration

Percent

Speed

100%

Start Run

Time (seconds)

Stop

The basic parameter set for Linear Speed follows:

Table 1.F: Linear Speed Acceleration Parameters

Parameter

SMC Option

Starting Mode

Ramp Time

Current Limit Level

Kickstart Time

Kickstart Level

Option 2

Stop Mode

Stop time

Standard

Linear Speed

0.0…30.0 s

0…600% FLC (Full Load Current)

0.0…2.0 s

0…90% LRT

Disable

Linear Speed

0.0…120.0 s

Adjustments

1-18

Bulletin 150 SMC Flex™

Figure 1.18: Linear Speed Acceleration Sequence of Operation

100%

Motor

Speed

Coast-to-rest

Soft Stop or

Linear Speed

Start

Soft Stop

Run

Time (seconds)

Push Buttons

Start

Stop

Closed

Open

Closed

Open

Soft Stop or

Linear Speed

Closed

Open

Auxiliary Contacts

Normal

Closed

Open

Up-to-speed

Closed

Open

If Soft Stop Selected

If Coast-to-rest Selected

1-19

Bulletin 150 SMC Flex™

Figure 1.19: Linear Speed Acceleration Wiring Diagram

Control Power

Stop

Linear Stop

Start

11 12 13 14 15 16 17 18 19 20 21 22

SMC-Flex

Control Terminals Aux #1

Normal/Up-to-Speed/

Bypass

23 24 25 26 27 28 29 30 31 32 33 34

PTC

Input

TACH

Input

Ground

Fault

Fault

Contact

Alarm

Contact

Aux #2

Normal

Customer supplied.

Refer to the controller nameplate to verify the rating of the control power input rating.

Internal

Auxilary

Contacts

1-20

Bulletin 150 SMC Flex™

Soft Stop

The Soft Stop option can be used in applications requiring an extended coast-to-rest. The voltage ramp down time is user adjustable from 0…120 seconds. The Soft Stop time is adjusted independently from the start time. The load will stop when the voltage drops to a point where the load torque is greater than the motor torque.

Figure 1.20: Soft Stop

Percent

Voltage

Selectable Kickstart

100%

Coast-to-rest

Soft Stop

Initial

Torque

Start Run

Time (seconds)

The basic parameter setup for Soft Stop follows:

Table 1.G: Soft Stop Parameters

Parameter

SMC Option

Stop Mode

Stop Time

Standard, Braking, Pump

Soft Stop

0…120 seconds

Soft Stop

Adjustments

1-21

Bulletin 150 SMC Flex™

Figure 1.21: Soft Stop Sequence of Operation

100%

Motor

Speed

Start Run

Time (seconds)

Push Buttons

Start

Closed

Open

Stop

Soft Stop

Closed

Open

Closed

Open

Auxiliary Contacts

Normal

Closed

Open

Up-to-speed

Closed

Open

Coast-to-rest

Soft Stop

Soft Stop

If Soft Stop Selected

If Coast-to-rest Selected

1-22

Bulletin 150 SMC Flex™

Figure 1.22: Soft Stop Wiring Diagram

Control Power

Soft Stop

Stop

Start

11 12 13 14 15 16 17 18 19 20 21 22

SMC-Flex

Control Terminals Aux #1

Normal/Up-to-Speed/

Bypass

23 24 25 26 27 28 29 30 31 32 33 34

PTC

Input

TACH

Input

Ground

Fault

Fault

Contact

Alarm

Contact

Aux #2

Normal

Customer supplied.

Refer to the controller nameplate to verify the rating of the control power input rating.

Internal

Auxilary

Contacts

1-23

Bulletin 150 SMC Flex™

Pump Control

Pump Control Option with Selectable Kickstart

The SMC-Flex controller’s unique interactive Pump Control is designed to reduce fluid surges in pumping systems. It provides closed loop acceleration and deceleration control of centrifugal pump motors without the need for feedback devices.

The kickstart feature provides a boost at startup to break away loads that may require a pulse of high torque to get started. It is intended to provide a current pulse with user adjustable locked rotor torque from 0-90% and kickstart time from 0.0 to 2.0 seconds.

Figure 1.23: Pump Control Option with Selectable Kickstart

100%

Motor

Speed

Pump Start

Run

Time (seconds)

Pump Stop

The basic parameter setup for Pump Control follows:

Table 1.H: Pump Control Option Parameters

Parameter

SMC Option

Starting Mode

Start Time

Initial Torque

Kickstart Time

Kickstart Level

Stop Time

Anti-Backspin Timer

Pump

Pump Start

0…30 s

0…90% LRT

0.0…2.0 s

0…90% LRT

0…120 s

0…999 s

Adjustments

1-24

Bulletin 150 SMC Flex™

Figure 1.24: Pump Control Option Sequence of Operation

100%

Motor

Speed

Pump Start Run

Time (seconds)

Push Buttons

Start

Closed

Open

Stop

Pump Stop

Closed

Open

Closed

Open

Auxiliary Contacts

Normal

Closed

Open

Up-to-speed

Closed

Open

Pump Stop

If Pump Stop Selected

If Coast-to-rest Selected

Coast-to-rest

1-25

Bulletin 150 SMC Flex™

Figure 1.25: Pump Control Option Wiring Diagram

Control Power

Stop

Pump Stop

Start

11 12 13 14 15 16 17 18 19 20 21 22

SMC-Flex

Control Terminals

Aux #1

Normal/Up-to-Speed/

Bypass

23 24 25 26 27 28 29 30 31 32 33 34

PTC

Input

TACH

Input

Ground

Fault

Fault

Contact

Alarm

Contact

Aux #2

Normal

Customer supplied.

Refer to the controller nameplate to verify the rating of the control power input rating.

Internal

Auxilary

Contacts

1-26

Bulletin 150 SMC Flex™

Braking Control

SMB Smart Motor Braking Option

The SMB Smart Motor Braking option provides motor braking for applications, which require the motor to stop quickly. It is a microprocessor based braking system, which applies braking current to a motor. The strength of the braking current is adjustable from 0…400% of full load current.

Figure 1.26: Smart Motor Braking

100%

Smart Motor Braking

Motor

Speed

Coast-to-rest

Start Run

Time (seconds)

Brake

Automatic Zero Speed

Shut-off

The basic parameter setup for Smart Motor Braking follows:

Table 1.I: Smart Motor Braking Parameters

Parameter

SMC Option

Stop Mode

Braking Current

Braking

SMB

0…400% FLC

Adjustments

1-27

Bulletin 150 SMC Flex™

Figure 1.27: Smart Motor Braking Sequence of Operation

100%

Motor

Speed

Push Buttons

Start

Stop

Smart Motor

Braking

Closed

Open

Closed

Open

Closed

Open

Auxiliary Contacts

Normal

Closed

Open

Up-to-speed

Closed

Open

Start Run

Time (seconds)

Smart Motor Braking

Coast-to-rest

Brake

Automatic Zero Speed

Shut-off

1-28

Bulletin 150 SMC Flex™

Figure 1.28: Smart Motor Braking Wiring Diagram

Control Power

Stop

Brake

Start

11 12 13 14 15 16 17 18 19 20 21 22

SMC-Flex

Control Terminals Aux #1

Normal/Up-to-Speed/

Bypass

23 24 25 26 27 28 29 30 31 32 33 34

PTC

Input

TACH

Input

Ground

Fault

Fault

Contact

Alarm

Contact

Aux #2

Normal

Customer supplied.

Refer to the controller nameplate to verify the rating of the control power input rating.

Internal

Auxilary

Contacts

1-29

Bulletin 150 SMC Flex™

Accu-Stop

The Accu-Stop option provides rapid braking to a slow speed, and then braking to stop, facilitating cost-effective general positioning control.

Figure 1.29: Accu-Stop

The basic parameter setup for Accu-Stop follows:

Table 1.J: Accu-Stop Parameters

Parameter

SMC Option

Stop Mode

Slow Speed Sel

Slow Accel Cur

Slow Running Cur

Braking Current

Stopping Current

Braking

Accu Stop

SS Low, SS High

0…450% FLC

0…450% FLC

0…400% FLC

0…400% FLC

Adjustments

1-30

Bulletin 150 SMC Flex™

Figure 1.30: Accu-Stop Sequence of Operation

100 %

Motor

Speed

Slow

Speed

Start Run

Time (seconds)

Slow Speed

Accu-Stop

Braking

Slow Speed

Braking

Coast-to-rest

Push Buttons

Start

Closed

Open

Stop

Closed

Open

Accu-Stop

Closed

Open

Auxiliary Contacts

Normal

Closed

Open

Up-to-speed

Closed

Open

If Coast-to-rest

Selected

Slow

Speed

Braking

1-31

Bulletin 150 SMC Flex™

Figure 1.31: Accu-Stop Wiring Diagram

Control Power

Accu-Stop

Stop

Start

11 12 13 14 15 16 17 18 19 20 21 22

SMC-Flex

Control Terminals Aux #1

Normal/Up-to-Speed/

Bypass

23 24 25 26 27 28 29 30 31 32 33 34

PTC

Input

TACH

Input

Ground

Fault

Fault

Contact

Alarm

Contact

Aux #2

Normal

Customer supplied.

Refer to the controller nameplate to verify the rating of the control power input rating.

Internal

Auxilary

Contacts

1-32

Bulletin 150 SMC Flex™

Slow Speed with Braking

The Slow Speed with Braking option combines the benefits of the SMB Smart Motor Braking and Preset Slow Speed options for applications that require slow setup speeds and braking to a stop.

Figure 1.32: Slow Speed with Braking

The basic parameter setup for Slow Speed with Braking follows:

Table 1.K: Slow Speed with Braking Parameters

Parameter

SMC Option

Option 2 Input

Slow Speed Sel

Slow Speed Dir

Slow Accel Cur

Slow Running Cur

Stop Mode

Braking Current

Braking

Preset SS

SS Low, SS High

SS Forward, SS Reverse

0…450% FLC

0…450% FLC

SMB

0…400% FLC

Adjustments

1-33

Bulletin 150 SMC Flex™

Figure 1.33: Slow Speed with Braking Sequence of Operation

100%

Motor

Speed

Slow Speed Start

Coast-to-Stop

Run

Time (seconds)

Braking

Brake

Push Buttons

Start

Closed

Open

Stop

Closed

Open

Slow Speed

Closed

Open

Brake

Closed

Open

Auxiliary Contacts

Normal

Closed

Open

Up-to-speed

Closed

Open

Brake

1-34

Bulletin 150 SMC Flex™

Figure 1.34: Slow Speed with Braking Wiring Diagram

Control Power

Stop

Brake

Slow Speed

Start

11 12 13 14 15 16 17 18 19 20 21 22

SMC-Flex

Control Terminals

Aux #1

Normal/Up-to-Speed/

Bypass

23 24 25 26 27 28 29 30 31 32 33 34

PTC

Input

TACH

Input

Ground

Fault

Fault

Contact

Alarm

Contact

Aux #2

Normal

Customer supplied.

Refer to the controller nameplate to verify the rating of the control power input rating.

Internal

Auxilary

Contacts

1-35

Bulletin 150 SMC Flex™

Features

SCR Bypass

The SMC-Flex has a built-in bypass contactor that is automatically pulled in when the motor reaches full speed. An external bypass contactor may be used. When an external bypass contactor is enabled (by setting the parameter “Aux1 Config” to “Bypass”) the internal bypass contactor will not be used, and a separate overload is required.

Standard or Wye-Delta Wiring

The SMC-Flex can operate either a standard squirrel-cage induction motor or a wye-delta motor.

The user must program the selected configuration into the unit using the “Motor Connection” parameter. The wye-delta motor is connected in an inside-the-delta wiring configuration, and the Motor Connection is det to Delta.

LCD Display

A graphical backlit LCD display provides parameter definition with straightforward text so that controller setup may be accomplished without a reference manual. Parameters are arranged in an organized three-level menu structure for ease of programming and fast access to parameters.

The displayed language can also be changed to meet global customer needs.

Parameter Programming

Programming of parameters is accomplished through a five-button keypad on the front of the

SMC-Flex controller. The five buttons include up and down arrows, an Enter button, a Select button, and an Escape button. The user needs only to enter the correct sequence of keystrokes for programming the SMC-Flex controller.

Figure 1.35: LCD Display with Keypad

LCD Display

Keypad

1-36

Bulletin 150 SMC Flex™

Electronic Overload

The SMC-Flex controller meets applicable requirements as a motor overload protective device.

Overload protection is accomplished electronically through current sensors and an I

2 t algorithm.

The overload trip class is selectable for OFF, 10, 15, 20, or 30 protection. The trip current is set by entering the motor’s full load current rating and the service factor.

Thermal memory is included to model motor operating and cooling temperatures. Ambient insensitivity is inherent in the electronic design of the overload.

Stall Protection and Jam Detection

Motors can experience locked rotor currents and develop maximum torque in the event of a stall

(during start) or a jam (after full speed is reached). These conditions can result in winding insulation breakdown or mechanical damage to the connected load.

The SMC-Flex controller provides both stall and jam detection for enhanced motor and system protection. Stall protection allows the user to program a maximum stall time of up to 10 seconds. Jam detection allows the user to determine the jam level as a percentage of the motor’s full load current rating, and a trip delay time of up to 99 seconds.

Note: The stall trip delay time is in addition to the programmed start time.

Figure 1.36: Stall Protection Sequence of Operation

600%

Percent

Full

Load

Current

Programmed Start Time

Time (seconds)

Stall

1-37

Bulletin 150 SMC Flex™

Figure 1.37: Jam Detection Sequence of Operation

Percent

Full

Load

Current

User Programmed Trip Level

100%

Running Jam

Time (seconds)

Ground Fault Protection

The SMC-Flex Controller can sense ground faults before they become ”short circuits.” Ground faults generally start at low levels (amps), but can rapidly increase to hundreds or thousands of amperes. This feature is not intended as a ground fault circuit-interrupter for personnel protection. The Ground Fault protection settings are user-adjustable. A separate Cat. No.

825-CBCT core balance current transformer is required for setup of this feature.

Thermistor Input

The SMC-Flex controller offers enhanced motor protection with additional circuitry to monitor motor stator-embedded positive temperature coefficient (PTC) thermistors. The PTC acts as a thermally sensitive resistor. It exhibits a large sudden increase in resistance at its activation temperature rating. Excessive motor heating can still occur without the motor being overloaded.

Such over-heating can result from blocked motor ventilation or high ambient temperatures, and the PTC will help identify this. The thermistor input settings are user adjustable. See the User

Manual for more details.

Metering

The SMC-Flex controller contains several power monitoring parameters as standard. These parameters include:

• Three-phase current

Three-phase voltage

• Power in kW

Power usage in kWH

• Power factor

Elapsed time

• Motor thermal capacity usage

1-38

Bulletin 150 SMC Flex™

Fault Indication

The SMC-Flex controller monitors both the pre-start and running modes. If the controller senses a fault, the SMC-Flex controller shuts down the motor and displays the appropriate fault condition in the LCD display. The controller monitors the following conditions:

Line Loss

• Shorted SCR

Open SCR Gate

• Thermistor (PTC)

Overtemperature (Power Pole, SCR, Motor)

• Bypass Failure

No Load

• Overvoltage

Undervoltage

• Overload

Underload

• Jam

Stall

• Phase Reversal

Phase Unbalance

• Current Unbalance

Voltage Unbalance

• Loss of Communication

Power Loss

• Excessive Starts/Hour

Ground Fault

• Motor Lead Loss

Line Fault

• Communication Fault

Any fault condition will cause the auxiliary contacts to change state and the hold-in circuit to release.

1-39

Bulletin 150 SMC Flex™

Parameter

Programming

Communication Capabilities

A serial interface port is furnished as standard with the SMC-Flex controller. This communication port allows connection to a Bulletin 20 Human Interface Module, and a variety of 20-COMM modules. These include Allen-Bradley Remote I/O™, DeviceNet™, ControlNet™,

Ethernet™, ProfiBUS, Interbus, and RS485.

Auxiliary Contacts

Four hard contacts are provided as standard with the SMC-Flex controller. The first contact is programmable for Normal/Up-to-speed/Bypass. The second, third and fourth contact are configured to N.O/N.C.

Modular Design

The SMC-Flex controller packaging is designed for industrial environments. The modularity of control and power modules feature plug-in functionality. There are no gate wires to remove and no soldering is required. Common control modules reduce inventory requirements.

Figure 1.38: Exploded View

1-40

Bulletin 150 SMC Flex™

Control Terminal Description

The SMC-Flex controller contains 24 control terminals on the front of the controller. These control terminals are described below. See Figure 1.39.

Table 1.L: Control Terminal Designation

Terminal Number

11

12

13

14

15

16

17

18

19

20

Description

Control Power Input

Control Power Common

Controller Enable Input ➀

Ground

Option Input #2 ➀

Option Input #1 ➀

Start Input ➀

Stop Input ➀

N.O. Aux. Contact #1

(Normal/Up-to-Speed/External Bypass) ➁

N.O. Aux. Contact #1

(Normal/Up-to-Speed/External Bypass) ➁

21

22

Not Used

Not Used

23

24

25

26

27

28

29

30

PTC Input ➀

PTC Input ➀

Tach Input

Tach Input

Ground Fault Transformer Input ➀

Ground Fault Transformer Input ➀

Fault Contact (N.O./N.C.)

Fault Contact (N.O./N.C.)

31

32

Alarm Contact (N.O./N.C.)

Alarm Contact (N.O./N.C.)

33

Aux Contact #2 Normal (N.O./N.C.)

34

Aux Contact #2 Normal (N.O./N.C.)

Do not connect any additional loads to these terminals. These “parasitic” loads may cause problems with operation, which may result in false starting and stopping.

External Bypass operates an external contactor and overload once the meter reaches full speed. The SMC-Flex overload functionality is disabled when the external bypass is activated. Proper sizing of the contactor and overload is required.

1-41

Bulletin 150 SMC Flex™

Figure 1.39: SMC-Flex Controller Control Terminals

11 12 13 14 15 16 17 18 19 20 21 22

SMC-Flex

Control Terminals

Aux #1

Normal/Up-to-Speed/External Bypass

23 24 25 26 27 28 29 30 31 32 33 34

PTC

Input

TACH

Input

Ground

Fault

Fault

Contact

Alarm

Contact

Aux #2

Normal

1-42

Bulletin 150 SMC Flex™

Overview

Chapter

2

Application Profiles for the SMC-Flex Controller

In this chapter, a few of the many possible applications for the SMC-Flex controller are described. The basis for selecting a particular control method is also detailed. Illustrations are included to help identify the application. Motor ratings are specified, but the ratings may vary in other typical applications.

For example, a tumbler drum is described as requiring the Soft Start feature. The application is examined further to determine how the SMC-Flex controller options can be used to improve the tumbler drum performance and productivity.

Figure 2.1: Compressor with Soft Start

AirFilter

InletValve

208...480Volts

50...250HP

50/60Hz

TurnValve

Ports

Problem: A compressor OEM shipped its equipment into overseas markets, where wye-delta motors are common. There were many different voltage and frequency requirements to meet because of the compressor’s final destination. Due to power company requirements and mechanical stress on the compressor, a reduced voltage starter was required. This made ordering and stocking spare parts difficult.

Solution: The SMC-Flex controller was installed and wired to a wye-delta motor. The unit was set for an 18-second Soft Start, which reduced the voltage to the motor during starting and met the power company requirements. By reducing the voltage, the starting torque was also reduced, minimizing the shock to the compressor. Panel space was saved because the SMC-Flex controller has a built-in overload and SCR bypass feature.

2-1

2-2

Bulletin 150 SMC Flex™

Figure 2.2: Tumbler with Soft Start and Accu-Stop

Loading Door

480 Volts

150 Hp

Drive Chain

Tumbler Drum

Motor

Problem: A tumbler drum used in the de-burring process was breaking the drive chain because of the uncontrolled acceleration from the across-the-line starter. To increase production on the drum, the coasting time on stop had to be reduced. Previous solutions were a separate soft start package plus a motor brake, which required additional panel space and power wiring. A small enclosure size and simplified power wiring were needed to reduce the cost of the controls.

Because a PLC was controlling several other processes in the facility, communication capabilities were desired.

Solution: The SMC-Flex controller with the braking option configured as Accu-Stop was installed on the process. The Soft Start provided a smooth acceleration of the drive chain, which reduced downtime. The controlled acceleration made positioning for loading/unloading easier. The drum was positioned for loading using the Preset Slow Speed. For unloading, the drum was rotated at Preset Slow Speed and then accurately stopped. This increased the productivity of the loading/unloading cycle. Further, the Accu-Stop option did not require additional panel space or wiring. The SMC-Flex controller’s built-in overload eliminated the need to mount an external overload relay in the enclosure. The built-in SCR Bypass eliminated the need for an external bypass contact in the enclosure. Both features saved further panel space. The communication feature of the SMC-Flex controller allowed remote starting and stopping of the process from a PLC.

Figure 2.3: Pump with Soft Start

Ground Level

Bulletin 150 SMC Flex™

480V

150 Hp

Check Valve

Motor

Pump

Problem: A municipal water company was experiencing problems with pump impellers being damaged. The damage occurred during frequent motor starting while the load below the check valve was draining from the system. A timing relay was installed to prevent restart underload, but need to be adjusted frequently.The pumping station motor was over 100 feet below ground, making repair costly. For maintenance scheduling purposes, an elapsed time meter measuring motor running time had to be installed in the enclosure.

Solution: The SMC-Flex controller with Pump control was installed, providing a controlled acceleration of the motor. By decreasing the torque during start up, the shock to the impeller was reduced. The SMC-Flex Anti-backspin timer feature was implemented to prevent the motor from starting while turning in a reverse direction. Panel space was saved by employing the built-in elapsed time meter. The SMC-Flex controller’s line diagnostics detected the pre-start and running single-phase condition and shut off the motor, protecting against motor damage.

2-3

2-4

Bulletin 150 SMC Flex™

Figure 2.4: Bandsaw with Soft Start and Slow Speed with Braking

480 Volts

300 Hp

Saw Blade

Log

Carriage

Motor

High Inertia Wheels

Problem: Because of the remote location of the facility and power distribution limitations, a reduced voltage starter was needed on a bandsaw application. When the saw blade became dull, the current drawn by the motor increased. Therefore, an ammeter was required. The saw was turned off only during shift changes or routinely to change the saw blade. This application required 25 minutes to coast to stop, and braking devices were unacceptable due to their high complexity and panel space requirements. After a blade was replaced, it was dangerous to bring the saw up to full speed because of alignment problems. Metering the application for jam conditions was a necessity. In addition, single phasing of the motor was a problem because of distribution limitations.

Solution: The SMC-Flex controller was installed to provide a reduced voltage start. This minimized the starting torque shock to the system. With the braking option configured as Slow

Speed with Braking, it provided a preset slow speed, allowing the saw blade tracking to be inspected before the motor was brought to full speed. The current monitoring and jam detection features of the SMC-Flex controller were implemented, saving valuable panel space and the cost of purchasing dedicated monitoring devices. The controller’s built-in programmable overload protection was used. The SMC-Flex controller’s diagnostic capabilities would detect single phasing and shut the motor off accordingly. Starting and stopping control was furnished in a single modular unit, providing ease of installation.

Figure 2.5: Rock Crusher with Soft Start

Bulletin 150 SMC Flex™

250 HP

480 Volts

Starts: Unloaded

Gearbox

Motor

Discharge

Problem: Because of the remote location of a rock quarry, the power company required a reduced voltage start on all motors over 150 Hp. The starting current on these large motors strained the capacity of the power system, causing severe voltage dips. When the rock crusher became overloaded, the current draw by the Wye-Delta motor increased. Therefore, current monitoring capabilities within the soft starter were required. Because the conveyor feeding the rock crusher was controlled by a PLC, communications between the soft starter and a PLC was necessary. When the rock crusher ran, occasionally a stall or jam would occur.

Solution: The SMC-Flex controller was installed, meeting the power company requirements.

The motor was wired inside-the-delta, which saves valuable panel space. The metering capabilities of the SMC-Flex controller allowed the current drawn by the motor to be monitored.

With the built-in communications capabilities, the motor current was communicated to the PLC.

When the motor current reached a specified limit, the conveyor feeding the rock crusher could be slowed. By slowing the conveyor, a jam condition in the rock crusher was avoided. The stall and jam detection capabilities of the SMC-Flex controller would shut off the motor when a stall or jam condition occurred.

2-5

2-6

Bulletin 150 SMC Flex™

Figure 2.6: Hammermill with Current Limit Start and SMB Smart Motor Braking

480 Volts

350 Hp

Belts

Hammer

Feed

Motor

Problem: A hammermill required a reduced voltage start because of power company restrictions. A stopping time less than the present 5 minute coast-to-rest was desired. To save panel space, the customer wanted to incorporate both starting and stopping control in the same device.

Solution: The SMC-Flex controller with the braking option configured as SMB Smart Motor

Braking was installed. A 23-second, 450% current limit acceleration was programmed, meeting the power company requirements and reducing the mechanical stress on the belts during startup. The braking function was accomplished without additional power wiring, panel space, or contactors. Zero speed was detected without additional sensors or timers. The current limit start, braking, and overload protection were accomplished within the same modular package.

Bulletin 150 SMC Flex™

Figure 2.7: Centrifuge with Current Limit Start and SMB Smart Motor Braking

480 Volts

400 Hp

Centrifuge

Motor

Gearbox

Problem: A centrifuge required a reduced voltage start because of power company restrictions.

The high torque during starting was causing damage to the gearbox. A shorter stopping time than the present 15 minute coast-to rest was desired. The long stop time caused delays in the production process. A Wye-Delta starter with a mechanical brake was currently in use. A zero-speed switch was used to release the brake. The mechanical brake required frequent maintenance and replacement, which was costly and time consuming. Both the mechanical brake and zero-speed switches were worn out and required replacement.

Solution: The SMC-Flex controller with the braking option configured as SMB Smart Motor

Braking was installed and wired inside-the-delta to the wye-delta motor. The controller was set for a 28-second, 340% current limit start, meeting the power company requirements and reducing the starting torque stress to the gearbox. SMB Smart Motor Braking allowed the centrifuge to stop in approximately 1 minute. The SMC-Flex controller with SMB Smart Motor

Braking did not require additional mounting space or panel wiring. The controller was mounted in a panel that was considerably smaller than the previous controller. Additionally, the controller did not require frequent maintenance and could sense zero speed without a feedback device.

2-7

2-8

Bulletin 150 SMC Flex™

Figure 2.8: Wire Draw Steel Mill Machine with Soft Start

Unwind

Spool

Die

Wire

575 Volts

35 Hp

Take-Up Spool

Chain

Motor

Problem: An across-the-line starter was used on a wire draw machine to pull wire. This rapid cycling application caused mechanical wear on both the chain and the electromechanical starter. Other soft starts had been experimented with, but not enough torque was developed to pull the wire through the die.

Solution: The SMC-Flex controller was installed to accelerate the motor smoothly. The kickstart feature was adjusted to provide enough torque to pull the wire through the die. After the initial kickstart, the controller went back to the soft start acceleration mode, reducing the amount of starting torque on the chain and helping to lower maintenance inspection and repair time. The controller was set for a 9-second ramp time.

Bulletin 150 SMC Flex™

Figure 2.9: Overload conveyor with Linear Speed and Tack Feedback

240 Vol

1.5 Hp

Chain

Conveyor

Motor Motor Motor

Problem: A overload gravel conveyor had three motors to drive the conveying system. Acrossthe-line starts caused damage to the conveyor and spilled gravel on the conveyor. Occasionally, the conveyor would stop fully loaded. An across-the-line start would then be needed to provide enough torque to accelerate the load.

Solution: The conveyor OEM installed a single SMC-Flex controller with linear speed and tach feedback to provide a smooth acceleration to all three motors, reducing the starting torque of the motors and the mechanical shock to the conveyor and load. In addition, the controller could be configured to simulate a full voltage start, allowing the conveyor to accelerate when fully loaded. The OEM liked the SMC-Flex controller because of its ability to control three motors as if they were a single motor, eliminating the need for multiple soft starters.

2-9

Bulletin 150 SMC Flex™

Figure 2.10: Ball Mill with Current Limit Start

Loading Port

480 Volts

150 Hp

Drum

Substance

Gearbox

Motor

Ball Shot

Problem: An across-the-line starter was used to start the motor in a ball mill application. The uncontrolled start was causing damage to the gearbox, resulting in maintenance downtime, as well as the potential for the loss of the product (paint) being mixed. Line failures were a frequent problem. The application required prestart and running protection, as well as an elapsed time meter to monitor the process time. Communication capability was desired, and panel space was limited.

Solution: The SMC-Flex controller was installed. It was programmed for a 26-second current limit start, thereby reducing the starting torque and the damage to the gearbox. The metering feature of the SMC-Flex controller contained an elapsed time meter, which could monitor the process time of the ball mill. The communications capabilities of the controller allowed the process time to be communicated to the PLC, which could remotely stop the ball mill. The line diagnostics required in the application are standard in the SMC-Flex controller, and the built-in overload protection and SCR Bypass saved panel space.

2-10

Bulletin 150 SMC Flex™

SMC-Flex

Controllers in

Drive

Applications

Chapter

3

Special Application Considerations

The SMC-Flex controller can be installed in starting and stopping control applications. A variable frequency drive must be installed when speed variation is required during run.

Use of Protective Modules

A protective module (see Figure 3.1) containing metal oxide varistors (MOVs) can be installed to protect the power components from electrical transients and/or electrical noise. The protective modules clip transients generated on the lines and prevent such surges from damaging the

SCRs.

Figure 3.1: Protective Module

PROTECTIVE MO

DULE

There are two general situations that may occur which would indicate the need for using the protective modules.

1.

Transient spikes may occur on the lines feeding the SMC-Flex controller (or feeding the load from the SMC-Flex controller). Spikes are created on the line when devices are attached with current-carrying inductances that are open-circuited. The energy stored in the magnetic field is released when the contacts open the circuit. Examples of these are lightly loaded motors, transformers, solenoids, and electromechanical brakes. Lightning can also cause spikes.

2.

The second situation arises when the SMC-Flex controller is installed on a system that has fast-rising wavefronts present, although not necessarily high peak voltages. Lightning strikes can cause this type of response. Additionally, if the SMC-Flex controller is on the same bus as other SCR devices, (AC/DC drives, induction heating equipment, or welding equipment) the firing of the SCRs in those devices can cause noise.

3-1

Bulletin 150 SMC Flex™

Motor Overload

Protection

When coordinated with the proper short-circuit protection, overload protection is intended to protect the motor, motor controller, and power wiring against overheating caused by excessive overcurrent. The SMC-Flex controller meets applicable requirements as motor overload protective device.

The SMC-Flex controller incorporates, as standard, electronic motor overload protection. This overload protection is accomplished electronically with circuits and an I

2 t algorithm.

The controller’s overload protection is programmable, providing the user with flexibility. The overload trip class can be selected for class OFF, 10, 15, 20, or 30 protection. The trip current can be programmed to the motor full load current rating.

Thermal memory is included to model motor operating and cooling temperatures. Ambient insensitivity is inherent in the electronic design of the overload.

Stall Protection and Jam

Detection

Motors can experience locked rotor currents and develop high torque levels in the event of a stall or a jam. These conditions can result in winding insulation breakdown or mechanical damage to the connected load.

The SMC-Flex controller provides both stall and jam detection for enhanced motor and system protection. Stall protection allows the user to program a maximum stall protection delay time from 0 to 10 seconds. The stall protection delay time is in addition to the programmed start time and begins only after the start time has timed out.

Jam detection allows the user to determine the motor jam detection level as a percentage of the motor’s full load current rating. To prevent nuisance tripping, a jam detection delay time, from 0…99 seconds, can be programmed. This allows the user to select the time delay required before the SMC-Flex controller will trip on a motor jam condition. The motor current must remain above the jam detection level during the delay time. Jam detection is active only after the motor has reached full speed.

3-2

Bulletin 150 SMC Flex™

Built-in

Communication

Power Factor

Capacitors

A serial interface port is furnished as standard on the SMC-Flex controller. The connections allows a Bulletin 20-COMM to be installed. Using the built-in communication capabilities, the user can remotely access parameter settings, fault diagnostics, and metering. Remote startstop control can also be performed.

When used with the Bulletin 20-COMM communication modules, the SMC-Flex controller offers true networking capabilities with several network protocols, including Allen-Bradley

Remote I/O, DeviceNet network, RS 485, ControlNet, EtherNet, ProfiBUS, and Interbus.

The controller may be installed on a system with power factor correction capacitors. These capacitors must be installed on the line side to prevent damage to the SCRs in the SMC-Flex controller (See Figure 3.2).

Figure 3.2: Power Factor Capacitors

3-Phase

Input Power

L1/1

L2/3

L3/5

T1/2

T2/4

T3/6

M

Branch

Protection

SMC-Flex

Controller

➀ Customer Supplied

➁ Overload protection is included as a

standard feature of the SMC-Flex controller.

Power Factor

Correction Capacitors

High values of inrush current and oscillating voltages are common when capacitors are switched. Therefore, additional impedance should be connected in series with the capacitor bank to limit the inrush current and dampen oscillations. The preferred practice is to insert aircore inductors as shown in Figure 3.3.

The inductors can be simply constructed:

• for volts greater than or equal to 460V: use a six-inch diameter coil with eight loops

• for volts less than 460V: use a six-inch diameter coil with six loops

The wire should be sized to carry the steady-state current that will flow through the capacitor bank during normal operations.

3-3

3-4

Bulletin 150 SMC Flex™

3-Phase

Input Power

Branch

Protection

The coils should be mounted on insulated supports away from metal parts. This will minimize the possibility of producing heating effects. Do not mount the coils to be stacked directly on top of each other. This will increase the chances of cancelling the effectiveness of the inductors.

If an isolation contactor is used, it is preferable that the power factor capacitors be installed ahead of the isolation contactor if at all possible (see Figure 3.3). In some installations, this may not be physically possible and the capacitor bank will have to be connected to the downstream terminals of the contactor. In this case, the installer must exercise caution and ensure that the air-core inductance is sufficient to prevent oscillating voltages from interfering with the proper performance of the SMC-Flex controller. It may be necessary to add more loops to the coil.

Figure 3.3: Power Factor Capacitors with Isolation Contactor

L1/1

L2/3

L3/5

T1/2

T2/4

T3/6

M

Isolation

Contactor

(IC)

SMC-Flex

Controller

Power Factor

Correction Capacitors

➀ Customer Supplied

➁ Overload protection is included as a

standard feature of the SMC-Flex controller.

Bulletin 150 SMC Flex™

Multi-motor

Applications

The SMC-Flex controller will operate with more than one motor connected to it. To size the controller, add the total nameplate amperes of all of the connected loads. The stall and jam features should be turned off. Separate overloads are still required to meet the National Electric

Code (NEC) requirements.

Note: The SMC-Flex controller’s built-in overload protection cannot be used in multi-motor applications.

Figure 3.4: Multi-Motor Application

3-Phase

Input Power

L1/1

L2/3

L3/5

Branch

Protection

➀ Customer Supplied

SMC-Flex

Controller

T1/2

T2/4

T3/6

Overload

Relay (O.L.)

Motor

No. 1

Motor

No. 2

Overload

Relay (O.L)

3-5

Bulletin 150 SMC Flex™

Special Motors

The SMC-Flex controller may be applied or retrofitted to special motors (wye-delta, part winding, synchronous, and wound rotor) as described below.

Wye-Delta

Wye-Delta is a traditional electro-mechanical method of reduced voltage starting. It requires a delta-wound motor with all its leads brought out to facilitate a wye connection. At the start command, approximately 58% of full line voltage is applied, generating about 33% of the motor’s full voltage starting torque capability. After an adjustable time interval, the motor is automatically connected in delta.

To apply an SMC-Flex controller to a wye-delta motor, the power wiring from the SMC-Flex controller is simply wired in an inside-the-delta configuration to the motor. This connects all six motor connections back to the SMC-Flex. Because the SMC-Flex controller applies a reduced voltage start electronically, the transition connection is no longer necessary. Additionally, the starting torque can be adjusted with parameter programming.

Note: Increased Hp ratings are achieved with the SMC-Flex being connected to wye-delta motors.

Figure 3.5: Inside-the-Delta Wiring.

1/L 3/L2 5/L3

12/T6 2/T1 8/T4 4/T2

10/T5

6/T3

M

3~

3-6

Bulletin 150 SMC Flex™

Altitude

De-rating

Part Winding

Part winding motors incorporate two separate, parallel windings in their design. With the traditional part winding starter, one set of windings is given full line voltage, and the motor draws about 400% of the motor’s full load current rating. Additionally, about 45% of locked rotor torque is generated. After a preset interval, the second winding is brought online in parallel with the first and the motor develops normal torque.

The part winding motor may be wired to an SMC-Flex controller by connecting both windings in parallel. Again, the starting torque can be adjusted to match the load with parameter programming.

Wound Rotor

Wound rotor motors require careful consideration when implementing SMC-Flex controllers. A wound rotor motor depends on external resistors to develop high starting torque. It may be possible to develop enough starting torque using the SMC-Flex controller and a single step of resistors. The resistors are placed in the rotor circuit until the motor reaches approximately 70% of synchronous speed. At this point, the resistors are removed from the secondary by a shorting contactor. Resistor sizing will depend on the characteristics of the motor used.

Please note that it is not recommended to short the rotor slip rings during start-up, as starting torque will be greatly reduced, even with full voltage applied to the motor. The starting torque will be even further reduced with the SMC-Flex controller since the output voltage to the motor is reduced on startup.

Synchronous

Synchronous, brush-type motors differ from standard squirrel-cage motors in the construction of the rotor. The rotor of a synchronous motor is comprised of two separate windings, a starting winding and a DC magnetic field winding.

The starting winding is used to accelerate the motor to about 95% of synchronous speed. Once there, the DC magnetic field winding is energized to pull the motor up to synchronous speed.

The SMC-Flex controller can be retrofitted to a synchronous controller by replacing the stator contactor with the SMC-Flex controller and maintaining the DC field application package.

Because of the decreased efficiency of fans and heatsinks, it is necessary to de-rate the

SMC-Flex controller above 6,500 feet (approximately 2,000 meters). When using the controller above 6,500 feet, use the next size device to guard against potential overtemperature trips.

Note: The motor FLA Rating must remain in the range of the SMC-Flex Amp rating.

3-7

Bulletin 150 SMC Flex™

Isolation

Contactor

When installed with branch circuit protection and an overcurrent device, SMC-Flex controllers are compatible with the National Electric Code (NEC). When an isolation contactor is not used, hazardous voltages are present at the load terminals of the power module even when the controller is turned off. Warning labels must be attached to the motor terminal box, the controller enclosure, and the control station to indicate this hazard.

The isolation contactor is used to provide automatic electrical isolation of the controller and motor circuit when the controller is shut down. Shut down can occur in either of two ways: either manually, by pressing the stop button, or automatically, by the presence of abnormal conditions (such as a motor overload relay trip).

Under normal conditions the isolation contactor carries only the load current. During start, the isolation contactor is energized before the SCRs are gated “on.” While stopping, the SCRs are gated “off” before the isolation contactor is de-energized. The isolation contactor is not making or breaking the load current.

Figure 3.6: Typical Connection Diagram with Isolation Contactor

3-Phase

Input Power

Branch

Protection

Isolation

Contactor

(IC)

L1/1

L2/3

L3/5

SMC-Flex

Controller

T1/2

T2/4

T3/6

M

➀ Customer Supplied

3-8

Bulletin 150 SMC Flex™

SMC-Flex

Controller with

Bypass

Contactor (BC)

Controlled start and stop are provided by wiring the controller as shown in Figure 3.7. When the motor is up to speed, the external bypass contactor is “pulled in” for run. The bypass mode must have a separate overload as the SMC-Flex overload is not active in this configuration.

Figure 3.7: Typical Application Diagram of a Bypass Contactor

3-Phase

Input Power

L1/1

L2/3

L3/5

T1/2

T2/4

T3/6

M

Branch

Protection

SMC-Flex

Controller

External BC

➀ Customer Supplied

➁ Overload protection is included as a standard feature of the SMC-Flex controller.

Note: Aux Contact #1 must be set to Bypass.

3-9

Bulletin 150 SMC Flex™

SMC-Flex

Controller with

Reversing

Contactor

By using the controller as shown in Figure 3.8, the motor accelerates under a controlled start mode in either forward or reverse.

Note: Minimum transition time for reversing is ½ second.

Phase Reversal must be OFF.

Figure 3.8: Typical Application with a Single-Speed Reversing Starter

3-Phase

Input Power

Branch

Protection

L1/1

L2/3

L3/5

T1/2

T2/4

T3/6

SMC-Flex

Controller

M

Reversing Contactors

➀ Customer Supplied

➁ Overload protection is included as a

standard feature of the SMC-Flex controller.

3-10

Bulletin 150 SMC Flex™

SMC-Flex

Controller as a

Bypass to an AC

Drive

By using the controller as shown in Figure 3.9, a soft start characteristic can be provided in the event that an AC drive is non-operational.

Note: A controlled acceleration can be achieved with this scheme, but speed control is not available in the bypass mode.

Figure 3.9: Typical Application Diagram of a Bypass Contactor for an AC Drive

AF

AF

➁ O.L.

3-Phase

Input Power

VFD

M

➀ ➀

VFD Branch

Protection

L1/1 T1/2

L2/3 T2/4

L3/5 T3/6

IC

IC

➀ Mechanical interlock required

➁ Customer supplied

SMC-Flex

Controller

➂ Many VF drives are rated 150% FLA. Because the SMC-Flex controller can be used for 600% FLA starting,

separate branch circuit protection may be required.

➃ Overload protection is included as a standard feature of the SMC-Flex controller.

3-11

Bulletin 150 SMC Flex™

SMC-Flex

Controller with a Bulletin 1410

Motor Winding

Heater

Figure 3.10: Typical Application Diagram of SMC-Flex Controller with a Bulletin 1410 Motor

Winding Heater

IC

O.L.

3-Phase

Input Power

L1/1

L2/3

T1/2

T2/4

L3/5 T3/6

SMC-Flex Controller

M

HC

➀ Customer supplied.

➁ Overload protection is included as a

standard feature of the SMC-Flex controller.

Bulletin 1410 MWH

3-12

Bulletin 150 SMC Flex™

Motor Torque

Capabilities with SMC-Flex

Controller

Options

SMB Smart Motor Braking

The stopping torque output of the SMC-Flex controller will vary depending on the braking current setting and motor characteristics. Typically the maximum stopping torque will be between 80…100% of the full load torque of the motor when set at 400% braking current.

Preset Slow Speed

Two torque characteristics of the Preset Slow Speed option must be considered. The first is the starting torque. The second is the available running torque at low speed (see Figure 3.11).

These torque characteristics will also vary, depending on the speed selected. Refer to Table 3.A for the approximate maximum available starting and running full load torque at maximum current settings. On adjustment (Slow Speed Current) will control the starting and running torque values.

Figure 3.11: Starting and Running Torque

100%

Motor

Speed

7 or 15%

Starting torque

Running torque

Time (seconds)

Table 3.A: Maximum Torque at Maximum Current Settings

Present Slow Speed

7%

15%

Maximum Starting Torque as a Percentage of

Full Load Torque

90…100%

50%

Maximum Running Torque as a Percentage of

Full Load Torque

110…120%

100%

3-13

Bulletin 150 SMC Flex™

Accu-Stop

Two levels of braking torque are applied with the Accu-Stop option. There is the braking portion that brakes to slow speed, and the slow speed braking/coast (see Figure 3.12). The level of these braking currents are adjusted using one rotary digital switch. The maximum braking torque available from braking to slow speed and from slow speed to stop is approximately

80…100% of full load torque of the motor. Using the slow speed starting portion of the Accu-

Stop option will result in the same starting and running torque characteristics as described in the Preset Slow Speed option.

Figure 3.12: Accu-Stop Option

Notes

100%

Braking

(A)

Motor

Speed

Slow Speed

Slow Speed

Braking/Coast

(B)

Time (seconds)

3-14

Bulletin 150 SMC Flex™

Chapter

4

Description

Product Line Applications Matrix

Use this chapter to identify possible SMC-Flex controller applications. This chapter contains an application matrix which will identify starting characteristics, as well as typical stopping features that may be used in various applications.

Mining and Metals

Applications

Soft Start

Current

Limit

Kickstart Soft Stop

SMC-Flex = X

Pump

Control

Accu-

Stop

Roller Mills

Hammermills

Roller Conveyors

Centrifugal Pumps

Fans

Tumbler

Rock Crusher

Dust Collector

Chillers

Compressor

Wire Draw

Machine

Belt Conveyors

Shredder

Grinder

Slicer

Overload Conveyor

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

Smart

Motor

Brake

X

X

Preset

Slow

Speed

Slow

Speed with

Brake

X

X

Linear

Speed

Acceleration

X

X

X

X

X

X

X

4-1

Bulletin 150 SMC Flex™

Food Processing

Applications

Centrifugal Pumps

Pallitizers

Mixers

Agitators

Centrifuges

Conveyors

Fans

Bottle Washers

Compressors

Hammermill

Separators

Dryers

Slicers

X

X

X

X

X

X

X

X

Soft Start

Current

Limit

Kickstart Soft Stop

SMC-Flex = X

Pump

Control

Accu-

Stop

X

X

X

X

X

X X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

Smart

Motor

Brake

Preset

Slow

Speed

Slow

Speed with

Brake

Linear

Speed

Acceleration

X

X

X

Pulp and Paper

Applications

Compressors

Conveyors

Trolleys

Dryers

Agitators

Centrifugal Pumps

Mixers

Fans

Re-Pulper

Shredder

Soft Start

Current

Limit

Kickstart Soft Stop

SMC-Flex = X

Pump

Control

Accu-

Stop

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

Smart

Motor

Brake

Preset

Slow

Speed

Slow

Speed with

Brake

Linear

Speed

Acceleration

X

X

4-2

Bulletin 150 SMC Flex™

Petrochemical

Applications

Centrifugal Pumps

Extruders

Screw Conveyors

Mixers

Agitators

Compressors

Fans

Ball Mills

Centrifuge

Soft Start

Current

Limit

Kickstart Soft Stop

SMC-Flex = X

Pump

Control

Accu-

Stop

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

Smart

Motor

Brake

Preset

Slow

Speed

Slow

Speed with

Brake

Linear

Speed

Acceleration

X

X

X

X

X

Transportation and Machine Tool

SMC-Flex = X

Applications

Soft Start

Current

Limit

Kickstart Soft Stop

Pump

Control

Accu-

Stop

Material Handling

Conveyors

Ball Mills

Grinders

Centrifugal Pumps

Trolleys

Presses

Fans

Palletizers

Compressors

Roller Mill

Die Charger

Rotary Table

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X X

X

X

X

X

X

X

X

X

X

Smart

Motor

Brake

X

X

Preset

Slow

Speed

Slow

Speed with

Brake

Linear Speed

Acceleration

X

X X

X

X

X

X

X

X

X

X

4-3

Bulletin 150 SMC Flex™

OEM Specialty Machine

Applications

Soft Start

Current

Limit

Kickstart Soft Stop

SMC-Flex = X

Pump

Control

Accu-

Stop

Centrifugal Pumps

Washers

Conveyors

Power Walks

Fans

Twisting/ Spinning

Machine

X

X

X

X

X

X

X

X

X

X

X

X

X X

X

X

X

X

Lumber and Wood Products

Applications

Soft Start

Current

Limit

Kickstart Soft Stop

SMC-Flex = X

Pump

Control

Accu-

Stop

Chipper

Circular Saw

Bandsaw

Edger

Conveyors

Centrifugal Pumps

Compressors

Fans

Planers

Sander

Debarker

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X X

X

X

X

Smart

Motor

Brake

Preset

Slow

Speed

Slow

Speed with

Brake

Linear

Speed

Acceleration

X

X

X

X

Smart

Motor

Brake

X

X

X

Preset

Slow

Speed

X

Slow

Speed with

Brake

X

X

X

Linear

Speed

Acceleration

X

X

X

X

X

X X

X

Water/Wastewater Treatment and Municipalities

SMC-Flex = X

Applications

Soft Start

Current

Limit

Kickstart Soft Stop

Pump

Control

Accu-

Stop

Centrifugal Pumps

Centrifuge

Fans

Compressors

X

X

X

X

X

X

X

X

X

Smart

Motor

Brake

X

Preset

Slow

Speed

Slow

Speed with

Brake

Linear

Speed

Acceleration

X

4-4

Bulletin 150 SMC Flex™

Chapter

5

Philosophy

Design Philosophy

Allen-Bradley SMC controllers are designed to operate in today’s industrial environments. Our controllers are manufactured to provide consistent and reliable operation. Rockwell Automation has more than just an adequate solution to meet your needs; we have the right solution. With a broad offering of power device products and application services, Rockwell Automation can effectively address the productivity issues most important to you.

Line Voltage

Conditions

Voltage transients, disturbances, harmonics and noise exist in any industrial supply. A solidstate controller must be able to withstand these noises and should not be an unnecessary source of generating noise back into the line.

Ease of selection for the required line voltage is achieved with a design that provides operation over a wide voltage range, at 50/60 Hz, within a given controller rating.

The controller can withstand 3000V surges at a rate of 100 bursts per second for 10 seconds

(IEEE Std. 472). Further, the controller can withstand the showering arc test of 350…1500V

(NEMA Std. ICS2-230) for higher resistance to malfunction in a noisy environment.

An optional MOV module is available to protect SCRs from voltage transients.

Current and

Thermal Ratings

Solid-state controller ratings must ensure reliability under the wide range of current levels and starting times needed in various applications.

SCR packaging keeps junction temperatures below 125°C (257°F) when running at full-rated current to reduce thermal stress and provide longer, more reliable operation.

The thermal capacity of the SMC-Flex controllers meet NEMA standards MG-1 and IEC34 (S1).

Mechanical

Shock and

Vibration

Solid-state controllers must withstand the shock and vibration generated by the machinery that they control.

SMC-Flex controllers meet the same shock and vibration specifications as electromechanical starters. They can withstand a 5 G shock for 11 ms in any plane and one hour of vibration of 1.0

G without malfunction.

Noise and RF

Immunity

This product meets Class A requirements for EMC emission levels.

5-1

Bulletin 150 SMC Flex™

Altitude

Pollution

Setup

Altitudes up to 2000 meters (6560 ft) are permitted without de-rating. The products’ allowable ambient temperature must be de-rated for altitudes in excess of 2000 meters (6560 ft). The allowable ambient temperature must be de-rated by –3°C (27°F) per 1000 meters (3280 ft), up to a maximum of 7000 meters (23000 ft). Current ratings of the devices do not change for altitudes that require a lower maximum ambient temperature.

This product is intended for a Pollution Degree 2 environment.

Simple, easily understood settings provide identifiable, consistent results.

For ease of installation, the controllers include compact design and feed-through wiring.

SMC-Flex controllers are global products rated at 50/60 Hz. All parameter adjustments are programmed into the controller through the built-in keypad. A full line of enclosures is available.

5-2

Bulletin 150 SMC Flex™

Chapter

6

Introduction to

Reduced

Voltage Starting

Reduced Voltage Starting

There are two primary reasons for using reduced voltage when starting a motor:

Limit line disturbances

• Reduce excessive torque to the driven equipment

The reasons for avoiding these problems will not be described. However, different methods of reduced voltage starting of motors will be explored.

When starting a motor at full voltage, the current drawn from the power line is typically 600% of normal full load current. This high current flows until the motor is almost up to speed and then decreases, as shown in Figure 6.1. This could cause line voltage dips and brown-outs.

Figure 6.1: Full-Load Current vs. Speed

%

Full

Load

Current

600

500

400

300

200

100

100

In addition to high starting currents, the motor also produces starting torques that are higher than full-load torque. The magnitude of the starting torque depends on the motor design. NEMA publishes standards for torques and currents for motor manufacturers to follow. Typically, a

NEMA Design B motor will have a locked rotor or starting torque in the area of 180% of fullload torque.

In many applications, this starting torque can cause excessive mechanical damage such as belt, chain, or coupling breakage.

6-1

Bulletin 150 SMC Flex™

Reduced

Voltage

Starting Method

Full Voltage

Autotrans.

80% tap

65% tap

50% tap

Part Winding

Wye-Delta

Solid-state

Figure 6.2:Bulletin 570 Autotransformer

The most widely used method of electromechanical reduced voltage starting is the autotransformer. Wye-

Delta (Y-D), also referred to as Star-Delta, is the next most popular method.

All forms of reduced voltage starting affect the motor current and torque characteristics. When a reduced voltage is applied to a motor at rest, the current drawn by the motor is reduced. In addition, the torque produced by the motor is a factor of approximately the square of the percentage of voltage applied.

For example, if 50% voltage is applied to the motor, a starting torque of approximately 25% of the normal starting torque would be produced. In the previous full voltage example, the NEMA Design B motor had a starting torque of 180% of full load torque. With only 50% voltage applied, this would equate to approximately 45% of full load torque. Table 6.A shows the typical relationship of voltage, current, and torque for a NEMA

Design B motor.

Table 6.A: Typical Voltage, Current and Torque Characteristics for NEMA Design B Motors

% Voltage at Motor

Terminals

100

Motor Starting Current as a % of:

Locked Rotor

Current

100

Full Load Current

600

Line Current as a % of:

Locked Rotor

Current

100

Full Load Current

600

Motor Starting Torque as a % of:

Locked Rotor

Torque

100

Full Load Torque

180

80

65

50

100

100

0…100

80

65

50

65

33

0…100

480

390

300

390

198

0…100

64

42

25

65

33

0…100

384

252

150

390

198

0…100

64

42

25

50

33

0…100

115

76

45

90

60

0…100

With the wide range of torque characteristics for the various starting methods, selecting an electromechanical reduced voltage starter becomes more application dependent. In many instances, available torque becomes the factor in the selection processes.

Limiting line current has been a prime reason in the past for using electromechanical reduced voltage starting. Utility current restrictions, as well as in-plant bus capacity, may require motors above a certain horsepower to be started with reduced voltage. Some countries require that any motor above 7½ Hp be started with reduced voltage.

Using reduced voltage motor starting also enables torque control. High inertia loads are a good example of an application in which electromechanical reduced voltage starting has been used to control the acceleration of the motor and load.

Electromechanical reduced voltage starters must make a transition from reduced voltage to full voltage at some point in the starting cycle. At this point, there is normally a line current surge.

The amount of surge depends upon the type of transition being used and the speed of the motor at the transition point.

6-2

Bulletin 150 SMC Flex™

There are two methods of transition: Open Circuit Transition and Closed Circuit Transition. Open circuit transition means that the motor is actually disconnected from the line for a brief period of time when the transition takes place. With closed transition, the motor remains connected to the line during transition. Open circuit transition will produce a higher surge of current because the motor is momentarily disconnected from the line. Examples of open and closed circuit transition currents are shown in Figure 6.3 and Figure 6.4.

Figure 6.3: Open Circuit Transition Figure 6.4: Closed Circuit Transition

%

Full

Load

Current

600

500

400

300

200

100

%

Full

Load

Current

600

500

400

300

200

100

100

100

The motor speed can determine the amount of current surge that occurs at transition. Transfer from reduced voltage to full voltage should occur at as close to full speed as possible. This also minimizes the amount of surge on the line.

Figure 6.5 and Figure 6.6 illustrate transition at low motor speed and near full speed. The transition at low speed shows the current surge as transition occurs at 550%, which is greater than the starting current of 400%. The transition near full speed shows that the current surge is

300%, which is below the starting current.

Figure 6.5: Transition at Low Speed Figure 6.6: Transition near Full Speed

%

Full

Load

Current

600

500

400

300

200

100

%

Full

Load

Current

600

500

400

300

200

100

100

100

6-3

Bulletin 150 SMC Flex™

SMC- Flex

Solid-State

The main function of solid-state controllers is their ability to provide a soft start or stepless reduced voltage start of AC motors. The same principles of current and torque apply to both electromechanical reduced voltage starters and solid-state controllers. Many solid-state controllers offer the choice of four starting modes: soft start, current limit start, dual ramp start, or full voltage start in the same device.

Figure 6.7: SMC-Flex Solid-State Controllers

5…85 A 108…251 A 317…480 A

In addition to selecting the starting modes, the solid-state controller allows adjustment of the time for the soft start ramp, or the current limit maximum value, which enables selection of the starting characteristic to meet the application. The most widely used version is the soft start.

This method provides a smooth start for most applications.

The major advantages of solid-state controllers are the elimination of the current transition point and the capability of adjusting the time to reach full voltage. The result is no large current surge when the solid-state controller is set up and correctly matched to the load, as illustrated in Figure 6.8.

6-4

Bulletin 150 SMC Flex™

Figure 6.8: Soft Start

Percent

Voltage

100%

Kickstart

Initial

Torque

Start Run

Time (seconds)

Current limit starting can be used in situations in which power line limitations or restrictions require a specific current load. Figure 6.9 shows a 450% current limit curve. Other values may be selected, such as 200%, 300%, or 400%, depending on the particular application. Current limit starting is also used in applications where higher starting torque is required compared to a soft start, which typically starts at less than 300% current. Current limit starting is typically used on low inertia loads, such as compressors.

Figure 6.9: Current Limit Start

600

%

Full

Load

Current

450

100

Other features available with solid-state controllers include additional protection to the motor and controller, and diagnostics to aid in setup and troubleshooting. Protection typically provided includes shorted SCR, phase loss, open load lead, SCR overtemperature, and stalled motor.

Appropriate fault messages are displayed to aid in troubleshooting when one of these faults trip out the solid-state reduced voltage controller.

6-5

Bulletin 150 SMC Flex™

Notes

6-6

Bulletin 150 SMC Flex™

Chapter

7

Solid-State Starters Using SCRs

In solid-state starters, silicon controlled rectifiers (SCRs) (see Figure 7.1) are used to control the voltage output to the motor. An SCR allows current to flow in one direction only. The amount of conduction of an SCR is controlled by the pulses received at the gate of the SCR. When two

SCRs are connected back to back (see Figure 7.2), the AC power to a load can be controlled by changing the firing angle of the line voltage (see Figure 7.3) during each half cycle. By changing the angle, it is possible to increase or decrease the voltage and current to the motor. The

SMC-Flex controller incorporates a microprocessor to control the firing of the SCRs. Six SCRs are used in the power section to provide full cycle control of the voltage and current. The voltage and current can be slowly and steplessly increased to the motor.

Figure 7.1: Silicon Controlled Rectifier (SCR)

SCR

Figure 7.2: Typical Wiring Diagram for SCRs

Power Input

3-Phase

L1 T1

L2

L3

T2

Motor

T3

SMC-Flex Controller

Power Section

7-1

7-2

Bulletin 150 SMC Flex™

Figure 7.3: Different Firing Angles (Single-Phase Simplification)

Supply

Voltage

Firing for

Approx.

50% RMS

Voltage

Firing for

25% RMS

Voltage

Firing for

100% RMS

Voltage

Bulletin 150 SMC Flex™

Chapter

8

Motor Output

Speed/Torque/

Horsepower

Reference

Certain mechanical parameters must be taken into consideration when applying motor controllers. The following section explains these parameters and how to calculate or measure them.

The speed at which an induction motor operates depends on the input power frequency and the number of poles for which the motor is wound. The higher the frequency, the faster the motor runs. The more poles the motor has, the slower it runs. To determine the synchronous speed of an induction motor, use the following equation:

Synchronous Speed =

60 x 2 x Frequency

Number of Poles

Actual full-load speed (the speed at which the motor will operate at nameplate rated load) will be less than synchronous speed. This difference between synchronous speed and full-load speed is called slip. Percent slip is defined as follows:

Percent Slip =

Synchronous Speed - Full Load Speed

Synchronous Speed x 100

Induction motors are built with slip ranging from less than 5% to as much as 20%. A motor with a slip of less than 5% is called a normal slip motor. Motors with a slip of 5% or more are used for applications requiring high starting torque.

8-1

Bulletin 150 SMC Flex™

Torque and

Horsepower

Torque and horsepower, two important motor characteristics, determine the size of the motor required for a given application. The difference between the two can be explained using a simple illustration of a shaft and wrench.

Figure 8.1:Shaft and Wrench

One Foot

One Pound

Torque is merely a turning effort. In the previous illustration, it takes one pound at the end of the one-foot wrench to turn the shaft at a steady rate. Therefore, the torque required is one pound × one foot, or one foot-lb. If the wrench were turned twice as fast, the torque required would remain the same, provided it is turned at a steady rate. Horsepower, on the other hand, takes into account how fast the shaft is turned.

Turning the shaft rapidly requires more horsepower than turning it slowly. Thus, horsepower is a measure of the rate at which work is done. By definition, the relationship between torque and horsepower is as follows:

1 Horsepower = 33,000 ft.-lb./minute

In the above example, the one pound of force moves a distance of:

2 ft. x

π x 1 lb. = 6.28 ft.-lb.

To produce one horsepower, the shaft would have to be turned at rate of:

1 Hp x 33,000 ft-lb./minute

6.28 ft-lb./revolution

= 5250 RPM

For this relationship, an equation can be derived for determining horsepower output from speed and torque.

Hp =

RPM x Torque X 2

30,000 or

RPM x Torque

5250

For this relationship, full-load torque is:

Full-Load Torque in ft.-lb. =

Hp x 5250

Full-Load RPM

8-2

Bulletin 150 SMC Flex™

Figure 8.2 illustrates a typical speed-torque curve for a NEMA Design B induction motor. An understanding of several points on this curve will aid in properly applying motors.

Figure 8.2: Speed-Torque Curve

Synchronous Speed

Breakdown Torque - BT

Locked Rotor Torque - LRT

% of

Full

Load

Torque

Pull Up Torque - PUT

Slip

Full Load Torque - FLT

Full Speed

Full-load Torque (FLT)

The full-load torque of a motor is the torque necessary to produce its rated horsepower at fullload speed. In foot-lbs, it is equal to the rated horsepower, multiplied by 5250, divided by the full-load speed in RPM.

Locked-Rotor Torque (LRT)

Locked-rotor torque is the torque which the motor will develop at rest for all angular positions of the rotor, with rated voltage at rated frequency applied. It is sometimes known as “starting torque” and is usually measured as a percentage of full-load torque.

Pull-Up Torque (PUT)

Pull-up torque of an induction motor is the minimum torque developed during the period of acceleration from locked rotor to the speed at which breakdown torque occurs. For motors that do not have definite breakdown torque (such as NEMA Design D), pull-up torque is the minimum torque developed, up to rated full-load speed, and is usually expressed as a percentage of full-load torque.

Breakdown Torque (BT)

The breakdown torque of an induction motor is the maximum torque the motor will develop with rated voltage applied, at rated frequency, without an abrupt drop in speed. Breakdown torque is usually expressed as a percentage of full-load torque.

8-3

8-4

Bulletin 150 SMC Flex™

In addition to the relationship between speed and torque, the relationship of current draw to these two values is an important application consideration. The speed/torque curve is repeated below, with the current curve added, to demonstrate a typical relationship.

Figure 8.3: Speed-Torque Curve with Current Curve

Locked Rotor

Current

Breakdown Torque - BT

Synchronous Speed

Locked Rotor

Torque - LRT

% of

Full

Load

Torque

Pull Up Torque - PUT

Slip

Full-load Torque - FLT

Full Speed

Full-load Current

Two important points on this current curve require explanation.

Full-load Current

The full-load current of an induction motor is the steady-state current taken from the power line when the motor is operating at full-load torque with rated voltage and rated frequency applied.

Locked-rotor Current

Locked-rotor current is the steady state current of a motor with the rotor locked and with rated voltage applied at rated frequency. NEMA has designed a set of code letters to define lockedrotor: Kilovolt-amperes-per-horsepower (kVA/Hp). This code letter appears on the nameplate of all AC squirrel-cage induction motors.

kVA per Hp is calculated as follows:

For three-phase motors: kVA/Hp =

1.73 x Current (in Amperes) x Volts

1000 x Hp

Bulletin 150 SMC Flex™

For single phase motors: kVA/Hp =

Current (in Amperes) x Volts

1000 x Hp

Letter Designation

A

B

C

D

E

F

K

L

G

H

J

U

V

S

T

P

R

M

N

kVA per Hp

0…3.15

3.15

3.55

3.55

4.0

4.0

4.5

4.5

5.0

5.0

5.6

5.6…6.3

6.3…7.1

7.1…8.0

8.0…9.0

9.0

10.0

10.0

11.2

11.2

12.5

12.5

14.0

14.0

16.0

16.0

18.0

18.0

20.0

20.0

22.4

22.4 and up

By manipulating the preceding equation for kVA/Hp for three-phase motors, the following equation can be used for calculating locked-rotor current:

LRA =

1000 x Hp x KVA/Hp

1.73 x Volts

This equation can then be used to determine the approximate starting current of any particular motor. For instance, the approximate starting current for 7½ Hp, 230V motor with a locked-rotor kVA code letter of G would be:

LRA =

1000 x 7.5 x 6.0

1.73 x 230

= 113 A

Operating a motor in a locked-rotor condition for an extended period of time will result in insulation failure because of the excessive heat generated in the stator. The following graph illustrates the maximum time a motor may be operated at locked-rotor without incurring damage caused by heating. This graph assumes a NEMA Design B motor with Class B temperature rise.

8-5

8-6

Bulletin 150 SMC Flex™

Figure 8.4: Motor Safe Time vs. Line Current — Standard Induction Motors

From Operating

Temperature

8

From Ambient

6

Motor

Line

Amps

Per

Unit

4

Motor Stalled

2

1

0

1.0 Serv. Factor

Motor

1.15 Serv. Factor

Time in Seconds

Motor

Motor Running

7000

Motor protection, either inherent or in the motor control, should be selected to limit the stall time of the motor.

Bulletin 150 SMC Flex™

Motor Output for NEMA Design Designations Polyphase 1…500 Hp

NEMA has designated several specific types of motors, each having unique speed/torque relationships. These designs, along with some typical applications for each type, are described below. Following these descriptions are summaries of performance characteristics.

Figure 8.5: Typical NEMA Design A Speed/Torque Curve

Starting Current: High

• Starting Torque: High

• Breakdown Torque: High

• Full-load Slip: Low

Torque

Applications: Fans, blowers, pumps, machine tools, or other applications with high starting torque requirements and an essentially constant load.

Speed

Figure 8.6: Typical NEMA Design B Speed/Torque Curve

• Starting Current: Normal

Starting Torque: Normal

• Breakdown Torque: Normal

Full-load Slip: Normal

Torque

Applications: Fans, blowers, pumps, machine tools, or other applications with normal starting torque requirements and an essentially constant load.

Speed

8-7

Bulletin 150 SMC Flex™

Figure 8.7: Typical NEMA Design C Speed/Torque Curve

• Starting Current: Low

Starting Torque: High

• Breakdown Torque: Low

Full-load Slip: Low

Torque

Applications: The higher starting torque of NEMA Design C motors makes them advantageous for use on hard-to-start loads such as plunger pumps, conveyors, and compressors.

Speed

Figure 8.8: Typical NEMA Design D Speed/Torque Curve

• Starting Current: Normal

• Starting Torque: High

• Breakdown Torque: None

Full-load Slip: High (5…13%)

Torque

Applications: The combination of high starting torque and high slip make NEMA Design D motors ideal for use on very high inertia loads and/or in applications where a considerable variation in load exists. These motors are commonly used on punch presses, shears, cranes, hoists, and elevators.

NEMA

Design

A

B

Starting

Torque

High

Normal

C

D

Low

Normal

Speed

Table 8.A: Motor Output - Comparison of NEMA Polyphase Designs

Locked

Rotor

Torque

Breakdown

Torque

% Slip Applications

High

Normal

High

High

High

Normal

Low

None

< 5%

< 5%

Low

High

5–8%

8–13%

Broad applications including fans, blowers, pumps, and machine tools.

Normal starting torque for fans, blowers, rotary pumps, unloaded compressors, conveyors, metal cutting, machine tools, miscellaneous machinery.

High inertia starts such as large centrifugal blowers, fly wheels and crusher drums. Loaded starts such as piston pumps, compressors and conveyors.

Very high inertia and loaded starts. Choice of slip range to match application.

Punch press, sheers and forming machine tools.

Cranes, hoists, elevators and oil well pumping jacks.

8-8

Bulletin 150 SMC Flex™

Calculating Torque (Acceleration Torque Required for Rotating

Motion)

Some machines must be accelerated to a given speed in a certain period of time. The torque rating of the drive may have to be increased to accomplish this objective. The following equation may be used to calculate the average torque required to accelerate a known inertia

(WK2). This torque must be added to all the other torque requirements of the machine when determining the drive and motor’s required peak torque output.

T =

WK

2

x (

∆N)

308 x t

Where:

• T = Acceleration Torque (ft.-lb.)

• WK

2

= total system inertia (ft.-lb.

2

) that the motor must accelerate. This value includes motor armature, reducer, and load.

∆N = Change in speed required (RPM)

• t = time to accelerate total system load (seconds).

Note: The number substituted for (WK

2

) in this equation must be in units of ft.-lb.

2

. Consult the conversion tables for the proper conversion factor.

The same formula can be used to determine the minimum acceleration time of a given drive, or it can be used to establish whether a drive can accomplish the desired change in speed within the required time period.

Transposed formula:

T =

WK

2

x (

∆N)

308 x t

General Rule — If the running torque is greater than the accelerating torque, use the running torque as the full-load torque required to determine the motor horsepower.

Note: The following equations for calculating horsepower are meant to be used for estimating purposes only. These equations do not include any allowance for machine friction, winding or other factors that must be considered when selecting a device for a machine application. After the machine torque is determined, the required horsepower is calculated using the formula:

Hp =

T x N

5250

Where:

Hp = Horsepower

8-9

Bulletin 150 SMC Flex™

T = Torque (ft.-lb.)

• N = Speed of motor at rated load (RPM)

If the calculated horsepower falls between standard available motor ratings, select the higher available horsepower rating. It is good practice to allow some margin when selecting the motor horsepower.

Inertia

Inertia is a measure of the body’s resistance to changes in velocity, whether the body is at rest or moving at a constant velocity. The velocity can be either linear or rotational.

The moment of inertia (WK

2

) is the product of the weight (W) of an object and the square of the radius of gyration (K

2

). The radius of gyration is a measure of how the mass of the object is distributed about the axis of rotation. Because of this distribution of mass, a small diameter cylindrical part has a much lower inertia than a large diameter part.

WK

2

or WR

2

Where:

• WR

2

refers to the inertia of a rotating member that was calculated by assuming the weight of the object was concentrated around its rim at a distance R (radius) from the center

(e.g., flywheel).

WK

2

refers to the inertia of a rotating member that was calculated by assuming the weight of the object was concentrated at some smaller radius, K (termed the radius of gyration). To determine the WK

2

of a part, the weight is normally required (e.g., cylinder, pulley, gear).

Torque Formulas

T

=

Hp x 5250

N

Where:

• Hp = Horsepower

T = Torque (ft.-lb.)

• N = Speed of motor at rated load (RPM)

T

=

F x R

Where:

• T = Torque (ft.-lb.)

F = Force (lb.)

• R = Radius (ft.)

8-10

T

(Accelerating) =

WK

2

x (

∆RPM)

308 x t

Where:

• T = Torque (ft.-lb.)

• WK

2

= Inertia reflected to the motor shaft (ft.-lb.

2

)

∆RPM = Change in speed

• t = Time to accelerate (s.)

Note: To change in-lb-sec.

2

to ft.-lb.

2

, multiply by 2.68.

To change ft.-lb.

2

to in-lb-sec.

2

, divide by 2.68.

AC Motor Formulas

Synchronous Speed =

Frequency x 120

Number of Poles

Where:

• Synchronous Speed = Synchronous Speed (RPM)

Frequency = Frequency (Hz)

Percent Slip =

Synchronous Speed - Full-Load Speed

Synchronous Speed x 100

Where:

• Full-Load Speed = Full Load Speed (RPM)

• Synchronous Speed = Synchronous Speed (RPM)

Reflected WK

2

=

WK

2

of Load

(Reduction Rate)

2

Where:

WK

2

= Inertia (ft.-lb.

2

)

Bulletin 150 SMC Flex™

8-11

Bulletin 150 SMC Flex™

Torque Characteristics on Common Applications

This chart offers a quick guideline on the torque required to breakaway, start and run many common applications.

Table 8.B: Torque Characteristics on Common Applications

Application

Agitators:

Liquid

Slurry

Blowers, centrifugal:

Valve closed

Valve open

Blowers, positive-displacement, rotary, bypassed

Card machines, textile

Centrifuges (extractors)

Chippers, wood, starting empty

Compressors, axial-vane, loaded

Compressors, reciprocating, start unloaded

Conveyors, belt (loaded)

Conveyors, drag (or apron)

Conveyors, screw (loaded)

Conveyors, shaker-type (vibrating)

Draw presses (flywheel)

Drill presses

Escalators, stairways (starting unloaded)

Fans, centrifugal, ambient:

Valve closed

Valve open

Fans, centrifugal, hot:

Valve closed

Valve open

Fans, propeller, axial-flow

Feeders, (belt) loaded

Feeders, distributing, oscillating drive

Feeders, screw, compacting rolls

Feeders, screw, filter-cake

Feeders, screw, dry

Feeders, vibrating, motor-driven

Frames, spinning, textile

Grinders, metal

Ironers, laundry (mangles)

Jointers, woodworking

Machines, bottling

Machines, buffing, automatic

Machines, cinder-block, vibrating

Machines, keyseating

Machines, polishing

Load Torque as Percent of Full Load Drive Torque

Breakaway Accelerating Peak Running

100

150

50

25

50

150

175

175

150

40

50

40

100

30

40

40

100

25

25

50

150

50

150

150

50

25

50

25

50

150

150

150

175

25

25

40

100

100

100

125

50

75

150

150

125

50

50

50

75

150

100

100

100

60

200

110

120

50

50

75

130

150

100

150

60

40

100

50

50

110

40

110

60

110

100

100

100

100

100

75

200

150

100

125

200

100

100

40

100

100

100

50

100

125

100

100

70

100

100

100

125

100

100

100

100

100

100

100

175

100

100

8-12

Bulletin 150 SMC Flex™

Application

Mills, flour, grinding

Mills, saw, band

Mixers, chemical

Mixers, concrete

Mixers, dough

Mixers, liquid

Mixers, sand, centrifugal

Mixers, sand, screw

Mixers, slurry

Mixers, solids

Planers, woodworking

Presses, pellet (flywheel)

Presses, punch (flywheel)

Pumps, adjustable-blade, vertical

Pumps, centrifugal, discharge open

Pumps, oil-field, flywheel

Pumps, oil, lubricating

Pumps, oil fuel

Pumps, propeller

Pumps, reciprocating, positive displacement

Pumps, screw-type, primed, discharge open

Pumps, Slurry-handling, discharge open

Pumps, turbine, centrifugal, deep-well

Pumps, vacuum (paper mill service)

Pumps, vacuum (other applications)

Pumps, vane-type, positive displacement

Rolls, crushing (sugar cane)

Rolls, flaking

Sanders, woodworking, disk or belt

Saws, band, metalworking

Saws, circular, metal, cut-off

Saws, circular, wood, production

Saws, edger (see edgers)

Saws, gang

Screens, centrifugal (centrifuges)

Screens, vibrating

Separators, air (fan-type)

Shears, flywheel-type

Textile machinery

Walkways, mechanized

Washers, laundry

50

150

50

25

60

40

50

40

30

30

30

25

50

60

40

150

30

175

150

150

50

150

40

40

40

150

150

50

40

175

150

175

50

Load Torque as Percent of Full Load Drive Torque

Breakaway

50

Accelerating

750

Peak Running

100

50

175

75

75

200

100

40

175

100

50

50

125

100

100

100

100

100

100

100

125

125

125

75

75

40

100

150

100

125

100

100

100

175

150

200

150

150

100

30

100

100

100

100

60

150

50

50

50

50

50

30

100

100

100

150

150

150

100

175

100

175

100

100

100

200

150

150

100

50

100

50

75

30

60

150

100

120

90

100

100

150

125

70

100

8-13

Bulletin 150 SMC Flex™

Electrical Formulas

Ohm’s Law:

I

=

R

R

=

I

Where:

I = Current (Amperes)

E = EMF or Voltage (Volts)

R = Resistance (Ohms)

E

=

I

×

R

Power in DC Circuits:

P kW

=

=

I

×

I

E

×

E

1,000

HP

=

I

×

746

E kWH =

I

×

E Hour

1,000

Where:

P = Power (Watts)

I = Current (Amperes)

E = EMF or Voltage (Volts) kW = Kilowatts kWH = Kilowatt-Hours kVA (1-phase)

=

I

×

E

1,000 kVA (3-phase)

=

I

×

E 1.73

1,000

Where: kVA = Kilovolt-Amperes

I = Current (Amperes)

E = EMF or Voltage (Volts) kW (1-phase)

=

I

×

E PF

1,000 kW (2-phase)

=

I

×

E

×

PF 1.42

1,000 kW (3-phase)

=

I

×

E

×

PF 1.73

1,000

8-14

PF

=

V

×

I

= kVA

Where: kW = Kilowatts

I = Current (Amperes)

E = EMF or Voltage (Volts)

PF = Power Factor

W = Watts

V = Volts kVA = Kilovolt-Amperes

Calculating Motor Amperes

Motor Amperes

=

HP

×

746

E

×

1.732

×

Eff

×

PF

Motor Amperes

= -------------------------

1.73

×

E

Motor Amperes

= kW

×

1,000

1.73

×

E PF

Where:

HP = Horsepower

E = EMF or Voltage (Volts)

Eff = Efficiency of Motor (%/100) kVA = Kilovolt-Amperes kW = Kilowatts

PF= Power Factor

Bulletin 150 SMC Flex™

8-15

Bulletin 150 SMC Flex™

Other Formulas

Calculating Accelerating Force for Linear Motion:

F (Acceleration)

=

×

1,933

V

× t

Where:

F = Force (lb.)

W = Weight (lb.)

∆V

= Change in Velocity (FPM) t = Time to accelerate weight (seconds)

LRA

=

HP

×

------------------

E

×

1.73

×

1,000

HP

------------------------------------------------------

Where:

LRA = Locked Rotor Amperes

HP = Horsepower kVA = Kilovolt-Amperes

E = EMF or Voltage (Volts)

LRA @ Freq. X

=

Freq. X

Where:

60 Hz LRA = Locked Rotor Amperes

Freq. X = Desired frequency (Hz)

8-16

Notes

Bulletin 150 SMC Flex™

8-17

Bulletin 150 SMC Flex™

Notes

8-18

www.rockwellautomation.com

Corporate Headquarters

Rockwell Automation, 777 East Wisconsin Avenue, Suite 1400, Milwaukee, WI, 53202-5302 USA, Tel: (1) 414.212.5200, Fax: (1) 414.212.5201

Headquarters for Allen-Bradley Products, Rockwell Software Products and Global Manufacturing Solutions

Americas: Rockwell Automation, 1201 South Second Street, Milwaukee, WI 53204-2496 USA, Tel: (1) 414.382.2000, Fax: (1) 414.382.4444

Europe: Rockwell Automation SA/NV, Vorstlaan/Boulevard du Souverain 36-BP 3A/B, 1170 Brussels, Belgium, Tel: (32) 2 663 0600, Fax: (32) 2 663 0640

Asia Pacific: Rockwell Automation, 27/F Citicorp Centre, 18 Whitfield Road, Causeway Bay, Hong Kong, Tel: (852) 2887 4788, Fax: (852) 2508 1846

Headquarters for Dodge and Reliance Electric Products

Americas: Rockwell Automation, 6040 Ponders Court, Greenville, SC 29615-4617 USA, Tel: (1) 864.297.4800, Fax: (1) 864.281.2433

Europe: Rockwell Automation, Brühlstraße 22, D-74834 Elztal-Dallau, Germany, Tel: (49) 6261 9410, Fax: (49) 6261 1774

Asia Pacific: Rockwell Automation, 55 Newton Road, #11-01/02 Revenue House, Singapore 307987, Tel: (65) 351 6723, Fax: (65) 355 1733

Publication 150-AT002B-EN-P — June 2004

Supersedes Publication 150-AT002A-EN-P — January 2003

 2004 Rockwell Automation. All Rights Reserved. Printed in USA

Was this manual useful for you? yes no
Thank you for your participation!

* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project

Download PDF

advertisement

Table of contents