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Rockwell Automation Publication 750-UM006C-EN-P - March 2022
Chapter 6
Troubleshooting
Fault Types, Descriptions,
and Actions
This section contains a table of faults and conditions that could occur and
provides guidance on how to resolve them.
ATTENTION:
This unit has remote sources of power. Disconnect all power
sources before the cover is removed. Failure to comply could result in death
or serious injury.
ATTENTION:
Do not attempt to service internal components when the unit
is energized. Complete lock out / tag out procedures for all input power
sources. Then, remove input power to receptacle L123 and 24V DC control
power to receptacles CP and CPBR (if used) before cover removal and
inspection. Failure to comply can result in death or serious injury.
ATTENTION:
The 24V DC control power source can be used to aid in
troubleshooting, but you must follow local codes while the control power is
energized, input power L123 is not energized, and the cover is removed.
Control power is connected to receptacles CP (24V DC auxiliary power) and
CPBR (24V DC brake options: B2 and B3). Failure to comply can result in
serious injury or death.
Issue
Description / Possible Cause
Action
PowerFlex 755® Alarms and Faults: motor/system does
not run.
Alarms and Faults are annunciated on the HIM and the
drive status is transmitted to the PLC via EtherNet/IP.
See the HIM manual found in the
for details on using the 20-HIM-C6S to view Faults
and alarm details.
See the programming manual found in the
for details on PowerFlex 755 faults
and alarms.
(1)
Brake Contactor Status: no mechanical brake voltage at
motor brake coil.
See the electrical schematics for details on the brake
contactor coil wiring. Depending on which option is used,
24V DC is provided from Receptacle CP pins 1 and 4 or
from the S4 safety option module safety output 0. In
either case, 24V DC must be provided to terminals R0C
and TC to be able to sequence the brake contactor.
Use the HIM, Connected Components Workbench™ ,
DriveExecutive™, or Studio 5000™ Logix Designer to
monitor the status of the brake contactor. The brake
contactor auxiliary is wired to Digital Input 0.
• Go to
07:01 [Dig In Sts] bit 0
to provide
confirmation of the brake contactor status. 0 = open/
set, 1 = closed/released. Monitor this parameter to
see if it opens and closes as desired for the application.
• If it doesn't function as desired, check
07:10 [Relay
Out 0]
and
07:20 [Transistor Output 0]
to see how
they are configured.
These two outputs are wired in parallel to control the
brake contactor coil.
07:06 [Digital Out Invert]
can be
used to change the state of the output to the brake
contactor coil when controlled by Logix in I/O mode (but
not in Integrated Motion mode).
