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Rockwell Automation Publication 750-IN118A-EN-P - May 2021
Chapter 4 Power Wiring
Motor Considerations
Due to the operational characteristics of AC variable frequency drives, we
recommend motors with inverter grade insulation systems that are designed
to meet or exceed NEMA MG1 Part 31.40.4.2 standards for resistance to spikes
of 1600 volts.
Guidelines must be followed when using non-inverter grade motors to avoid
premature motor failures. See Wiring and Grounding Guidelines for Pulse
Width Modulated (PWM) AC Drives, publication
for
recommendations.
Grounding Requirements
The Safety Ground-PE must be connected to system ground.
Ground
impedance must conform to the requirements of national and local industrial
safety regulations and/or electrical codes. Periodically check the integrity of all
ground connections. For more information on grounding requirements, see
PowerFlex 755TM IP00/Open Type Kits Installation Instructions, publication
, and Wiring and Grounding Guidelines for Pulse Width Modulated
(PWM) AC Drives, publication
.
Recommended Grounding Scheme
A single point (PE only) grounding scheme should be used. Some applications
may require alternate grounding schemes. For information on alternate
grounding schemes, see the Wiring and Grounding Guidelines for Pulse
Width Modulated (PWM) AC Drives, publication
. The drawing
package that came with your order contains a schematic that provides
grounding information. See that schematic for specific grounding
recommendations.
The typical grounding information for a PowerFlex 755T Drives Configured to
Order Program product is the same as the typical grounding information for
the 755T standard products. For the typical grounding information, see the
Recommended Grounding Scheme section in the PowerFlex 750-Series
Products with TotalFORCE® Control Installation Instructions, publication
.
Grounding Clamps
Grounding clamps are provided with your product. You can order additional
grounding clamps using the information in
. The
grounding clamps can be used to secure round copper ground conductors to
9.5 mm (0.37 in.) thick ground busbars.
Figure 92 - Grounding Clamps Provided with the Product