Siemens SINAMICS PERFECT HARMONY GH180 Function Manual page 450

Troubleshooting Faults and Alarms
11.4 Drive Faults and Alarms Input Line Disturbance
Fault display
PreChrg Contactor Alarm
PreChrg Breaker Opened
448
Type Enable Potential causes and corrective actions
A Cause
During pre-charge, if any pre-charge contactor (M2, M3, and M4) does not
respond as directed, this alarm is issued along with a pre-charge fault.
After pre-charge completes, the command to the pre-charge contactor
(M2, M3, and M4) is compared to feedback (acknowledge) and if they do
not agree, an alarm is issued.
Possible causes include:
• No power to contactor coils.
• Incorrect wiring of contactors and auxiliary contacts.
• Defective user I/O module 1.
• Loose or defective fiber optic cable between DCR and NXGpro user I/O
module.
Action
1. Check for control power to contactors.
2. Check wiring; check connections to user I/O module 1.
3. Check fiber optic cable connection between DCR and NXGpro user I/O
module.
4. Replace user I/O module.
5. Replace DCR.
A Cause
This alarm indicates that the pre-charge breaker was commanded to open
when the precharge contactors M2, M3, or M4 failed to open. This alarm
is applicable to only pre-charge Type 5 or Type 6.
Possible causes include:
• Incorrect wiring from user I/O module 1 to the pre-charge contactors.
• The user I/O module is broken, which results in reporting incorrect
status of the contactors.
• Incorrect attenuation resistor values for required input voltage.
Action
1. Check pre-charge contactors and auxiliary contacts.
2. Replace user I/O module.
3. Evaluate wiring.
4. Check input protection fault and correct.
NXGPro+ Control Manual
Operating Manual, A5E50491925A