Rockwell Automation Publication 750-UM006C-EN-P - March 2022
23
Prepare for Installation
Chapter 2
Circuit Protection
Branch circuit protection for the drive is provided by the internal circuit
breaker, which complies with UL508 and CSA guidelines.
The feeder available fault current must not exceed 65,000 A RMS symmetrical
at 480V AC. Input feeder power fuse and/or circuit breaker protection is
required for the M35 input connector and you must provide it based on NEC
guidelines and specific local codes.
Refer to
for more information.
ATTENTION:
The PowerFlex 755 drive contains protective Metal Oxide
Varistors (MOVs) that are referenced to a ground. These devices must not be
disconnected or installed on an ungrounded and high resistive distribution
system. Failure to do so may lead to personal injury or death, property
damage, or economic loss.
IMPORTANT
The drive requires a solidly grounded delta-wye power source (for example,
480/277V AC or 400/230V AC, 3-phase power source). If applied to a
grounded or ungrounded 400/480V AC delta power source, abnormal
ground currents will be detected and cause the EMI filter to be damaged.
IMPORTANT
The safety ground, PE, must be connected to earth-grounding-system.
Some codes may require redundant ground paths and periodic examination
of connection integrity.
WARNING:
Circumstances that can cause an explosion may exist, which may
lead to personal injury or death, property damage, or economic loss. If the
branch circuit protection device trips, you must use the software to verify
that the source brake function is still operational before putting the
equipment back in service. If the source brake function is not working
properly, loss of brake function or motor damage can occur.
