Rockwell Automation 21G PowerFlex 750-Series AC Drives Programming Manual - Manual (Page 454)

454 Rockwell Automation Publication 750-PM001J-EN-P - October 2014
Appendix B Application Notes
Troubleshooting
The following faults commonly occur during drive commissioning.
F4 “Undervoltage”
• If the mains supply is still present, reduce the undervoltage level at P461
[UnderVltg Level].
F5 “Overvoltage”
• Monitor the DC Bus voltage while operating the crane. When lowering
the load, limit the DC bus voltage to 750V DC.
• Verify that the external resistor is correctly connected / wired
• Verify that the parameter settings as stated in Point 1.
• Monitor bit 20 DB active of P935 [Drive Status 1]. This bit comes on
when dynamic braking is active.
F20 “TrqProve Spd Band” (Speed deviation fault)
• This fault is only active when TorqProve is enabled.
• Speed loop tuning not correct. Increase P636 [Speed Reg BW] or P76
[Total Inertia]. If values are too high, the regulator becomes unstable.
• Verify P3 [Mtr Vel Fdbk] follows P594 [Ramped Spd Ref ] as best as
possible.
• Drive is going into current limit. Drive is undersized or acceleration /
deceleration are set too fast.
• Brake is not opening. Check for faulty brake rectifier.
For more fault information, see Chapter 6 .