Siemens SINAMICS G120 - F30021 Power unit: Ground fault; F30022 Power unit: Monitoring U_ce

4 Faults and alarms
4.2 List of faults and alarms
SINAMICS G120 Control Units CU240B-2/CU240E-2
860 List Manual (LH11), 01/2016, A5E33839529
- motor load too high
- power unit defective.
Fault value (r0949, interpret binary):
Bit 0: Phase U
Bit 1: Phase V
Bit 2: Phase W
Remedy: - check the motor data.
- check the motor circuit configuration (star-delta).
- check the motor load.
- check the power cable connections.
- check the power cables for short-circuit or ground fault.
- check the length of the power cables.
- replace power unit.
F30021 Power unit: Ground fault
Message class: Ground fault / inter-phase short-circuit detected (7)
Reaction: OFF2
Acknowledge: IMMEDIATELY
Cause: The power has detected a ground fault.
Possible causes:
- ground fault in the power cables.
- ground fault at the motor.
- CT defective.
- when the brake closes, this causes the hardware DC current monitoring to respond.
- short-circuit at the braking resistor.
Fault value (r0949, interpret decimal):
0:
- the hardware DC current monitoring has responded.
- short-circuit at the braking resistor.
> 0:
Absolute value, summation current [32767 = 271 % rated current].
Remedy: - check the power cable connections.
- check the motor.
- check the CT.
- check the cables and contacts of the brake connection (a wire is possibly broken).
- check the braking resistor.
See also: p0287 (Ground fault monitoring thresholds)
F30022 Power unit: Monitoring U_ce
Message class: Ground fault / inter-phase short-circuit detected (7)
Reaction: OFF2
Acknowledge: POWER ON
Cause: In the power unit, the monitoring of the collector-emitter voltage (U_ce) of the semiconductor has responded.
Possible causes:
- fiber-optic cable interrupted.
- power supply of the IGBT gating module missing.
- short-circuit at the power unit output.
- defective semiconductor in the power unit.
Fault value (r0949, interpret binary):
Bit 0: Short-circuit in phase U
Bit 1: Short circuit in phase V
Bit 2: Short-circuit in phase W
Bit 3: Light transmitter enable defective
Bit 4: U_ce group fault signal interrupted
See also: r0949 (Fault value)