Rockwell Automation Allen-Bradley 160-AA02 User manual

Installation Instructions
Wiring and Grounding
Guidelines for
Pulse Width Modulated
(PWM) AC Drives

Important User Information Solid state equipment has operational characteristics differing from those of
electromechanical equipment. Safety Guidelines for the Application,
Installation and Maintenance of Solid State Controls (Publication SGI-1.1
available from your local Rockwell Automation sales office or online at http://
www.rockwellautomation.com/literature) describes some important differences
between solid state equipment and hard-wired electromechanical devices.
Because of this difference, and also because of the wide variety of uses for solid
state equipment, all persons responsible for applying this equipment must
satisfy themselves that each intended application of this equipment is
acceptable.
In no event will Rockwell Automation, Inc. be responsible or liable for indirect
or consequential damages resulting from the use or application of this
equipment.
The examples and diagrams in this manual are included solely for illustrative
purposes. Because of the many variables and requirements associated with any
particular installation, Rockwell Automation, Inc. cannot assume responsibility
or liability for actual use based on the examples and diagrams.
No patent liability is assumed by Rockwell Automation, Inc. with respect to use
of information, circuits, equipment, or software described in this manual.
Reproduction of the contents of this manual, in whole or in part, without
written permission of Rockwell Automation, Inc. is prohibited.
Throughout this manual, when necessary we use notes to make you aware of
safety considerations.
Important: Identifies information that is critical for successful application and
understanding of the product.
PowerFlex is a registered trademark of Rockwell Automation, Inc.
DriveExplorer, DriveExecutive, and SCANport are trademarks of Rockwell Automation, Inc.
PLC is a registered trademark of Rockwell Automation, Inc.
!
WARNING: Identifies information about practices or
circumstances that can cause an explosion in a hazardous
environment, which may lead to personal injury or death, property
damage, or economic loss.
!
ATTENTION: Identifies information about practices or
circumstances that can lead to personal injury or death, property
damage, or economic loss. Attentions help you:
•identify a hazard
•avoid the hazard
•recognize the consequences
Shock Hazard labels may be located on or inside the equipment
(e.g., drive or motor) to alert people that dangerous voltage may be
present.
Burn Hazard labels may be located on or inside the equipment
(e.g., drive or motor) to alert people that surfaces may be at
dangerous temperatures.

Summary of Changes
The information below summarizes the changes to the Wiring and
Grounding Guidelines for Pulse Width Modulated AC Drives, publication
DRIVES-IN001, since the last release.
Manual Updates
Change Page
Revised guidelines for AC line impedance. 2-5
Revised guidelines for multi-drive protection 2-15
Revised guidelines for MOVs and common mode
capacitors
2-17
Added footnote 4. A-10

ii Summary of Changes
Notes:

Table of Contents
Important User Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
Summary of
Changes
Preface Overview
Who Should Use This Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P-1
Recommended Documentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P-1
Manual Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P-2
General Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P-2
Chapter 1 Wire/Cable Types
General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
Input Power Cables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-10
Motor Cables. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-10
Cable for Discrete Drive I/O . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-11
Analog Signal and Encoder Cable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-12
Communications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-12
Chapter 2 Power Distribution
System Configurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
AC Line Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4
AC Line Impedance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5
Surge Protection MOVs and Common Mode Capacitors . . . . . . . . . . . . . . . . . . . . . . . . 2-17
Chapter 3 Grounding
Grounding Safety Grounds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1
Noise Related Grounds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3
Chapter 4 Practices
Mounting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1
Conduit Entry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4
Ground Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-6
Wire Routing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-9
Conduit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-13
Cable Trays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-14
Shield Termination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-15
Conductor Termination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-18
Moisture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-18
Chapter 5 Reflected Wave
Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1
Effects On Wire Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1
Length Restrictions For Motor Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2

ii
Chapter 6 Electromagnetic Interference
What Causes Common Mode Noise . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1
Containing Common Mode Noise With Cabling. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-2
How Electromechanical Switches Cause Transient Interference . . . . . . . . . . . . . . . . . . . 6-3
How to Prevent or Mitigate Transient Interference from Electromechanical Switches . . 6-4
Enclosure Lighting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-7
Appendix A Motor Cable Length Restrictions Tables
PowerFlex 4 and 40 Drives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-8
PowerFlex 400 Drives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-8
Glossary
Index

Preface
Overview
The purpose of this manual is to provide you with the basic information
needed to properly wire and ground Pulse Width Modulated (PWM) AC
drives.
Who Should Use This
Manual
This manual is intended for qualified personnel who plan and design
installations of Pulse Width Modulated (PWM) AC drives.
Recommended
Documentation
The following publications provide general drive information.
Title Publication Available…
Installing, Operating and
Maintaining Engineered Drive
Systems (Reliance Electric)
D2-3115-2
Safety Guidelines for the
Application, Installation and
Maintenance of Solid State Control
SGI-1.1 www.rockwellautomation.com/
liiterature
IEEE Guide for the Installation of
Electrical Equipment to Minimize
Electrical Noise Inputs to
Controllers from External Sources
IEEE 518
Recommended Practice for
Powering and Grounding
Electronic Equipment - IEEE
Emerald Book
IEEE STD 1100
Electromagnetic Interference and
Compatibility, Volume 3
N/A RJ White - publisher
Don White Consultants, Inc., 1981
Grounding, Bonding and Shielding
for Electronic Equipment and
Facilities
Military Handbook 419
IEEE Recommended Practice for
Grounding of Industrial and
Commercial Power Systems
IEEE Std 142-1991
National Electrical Code (ANSI/
NFPA 70)
Articles 250, 725-5,
725-15, 725-52 and
800-52
Noise Reduction Techniques in
Electronic Systems
N/A Henry W. Ott
Published by Wiley-Interscience
Grounding for the Control of EMI N/A Hugh W. Denny
Published by Don White Consultants
Cable Alternatives for PWM AC
Drive Applications
IEEE Paper No.
PCIC-99-23
EMI Emissions of Modern PWM
AC Drives
N/A IEEE Industry Applications
Magazine, Nov./Dec. 1999
EMC for Product Designers N/A Tim Williams
Published by Newnes

p-2 Overview
Manual Conventions The following words are used throughout the manual to describe an action:
General Precautions
Application Guide for AC
Adjustable Speed Drive Systems
N/A NEMA
www.nema.org
IEC 60364-5-52 Selection &
Erection of Electrical Equipment -
Wiring systems
N/A IEC
www.iec.ch
Don’t Ignore the Cost of Power
Line Disturbance
1321-2.0 www.rockwellautomation.com/
liiterature
Title Publication Available…
Word Meaning
Can Possible, able to do something
Cannot Not possible, not able to do something
May Permitted, allowed
Must Unavoidable, you must do this
Shall Required and necessary
Should Recommended
Should Not Not recommended
!
ATTENTION: To avoid an electric shock hazard, verify that the
voltage on the bus capacitors has discharged before performing
any work on the drive. Measure the DC bus voltage at the +DC &
–DC terminals of the Power Terminal Block. The voltage must be
zero.

Chapter 1
Wire/Cable Types
AC drive installations have specific requirements for cables. Wire or cable
selection for a drive application must consider a variety of criteria.
The following section covers the major issues and proper selection of cable.
Recommendations are made to address these issues. Cable materials and
construction must consider the following:
•Environment including moisture, temperature and harsh or corrosive
chemicals.
•Mechanical needs including geometry, shielding, flexibility and crush
resistance.
•Electrical characteristics including cable capacitance/charging current,
resistance/voltage drop, current rating and insulation. Insulation may be
the most significant of these. Since drives can create voltages well in
excess of line voltage, the industry standard cables used in the past may
not represent the best choice for customers using variable speed drives.
Drive installations benefit from using cable that is significantly different
than cable used to wire contactors and push buttons.
•Safety issues including electrical code requirements, grounding needs
and others.
Choosing incorrect cable can be costly and may adversely affect the
performance of your installation.

1-2 Wire/Cable Types
General Material
Use Copper wire only. The wire clamp type terminals in Allen-Bradley
drives are made for use with copper wire only. If you use aluminum wire the
connections may loosen.
Wire gauge requirements and recommendations are based on 75 degrees C.
Do not reduce wire gauge when using higher temperature wire.
Exterior Cover
Whether shielded or unshielded, the cable must be chosen to meet all of the
application requirements. Consideration must be given to insulation value
and resistance to moisture, contaminants, corrosive agents and other
invasive elements. Consult the cable manufacturer and the chart below for
proper selection.
Figure 1.1 Wire Selection Flowchart
Selecting Wire to Withstand Reflected Wave Voltage for New and Existing Wire Installations
in Conduit or Cable Trays
Conductor
Environment
Conductor
Insulation
Insulation
Thickness
XLPE
PVC
OK for < 600V AC
System
No RWR or
Terminator required
20 mil or > (1)
230V 400/460V
15 mil
RWR or
Terminator
No RWR or
Terminator
Cable
Length
# of
Drives in Same
Conduit or Wire
Tray
> 50 ft.
< 50 ft.
Single Drive,
Single Conduit
or Wire Tray
Multiple Drives
in Single Conduit
or Wire Tray
575V
No RWR
or Terminator
Reflected Wave
Reducer?
Reflected Wave
Reducer?
RWR or
Terminator
XLPE (XHHW-2)
Insulation for
<600V AC
System
No RWR or
Terminator
Required
15 mil PVC
Not
Recommended
USE XLPE
or > 20 mil
15 mil PVC
Not
Recommended
USE XLPE
or > 20 mil
See NEC Guidelines (Article 310
Adjustment Factors) for Maximum
Conductor Derating and Maximum
Wires in Conduit or Tray
(1) The mimimum wire size for PVC cable with 20 mil or greater insulation is 10 gauge.
DRY (Per
NEC Article 100)
WET (Per
NEC Article 100)