A: When these three faults appear together, the cause is very likely abnormal input power supply. Please follow the steps below to diagnose:
1.Check whether the input power supply to the UPS is abnormal.This kind of fault is especially common when the power source is a generator, transformer, or similar equipment.
2.Check that all circuit breakers connected to the UPS are closed,especially the input and bypass circuit breakers on the UPS.
3.Check for internal module faults on the UPS input side,such as a blown input fuse.