Huawei UPS5000-A - Page 165

Case Symptom Possible Cause Suggestion
Rectier
abnormal
The rectier of the
UPS power unit fails
to work, and the
UPS power unit
stops supplying
power.
The mains voltage
exceeds the upper
threshold 280 V or is
less than the lower
threshold 80 V.
Check whether the
mains voltage is
beyond the allowed
range. If so, contact
the electric power
company.
The power unit is
faulty:
● PFC soft-startup
fails.
● The DC bus is
short-circuited.
● The rectier
bridge current is
unbalanced.
● The input fuse is
broken.
● The discharger
SCR is short-
circuited and the
UPS transfers to
battery mode.
Replace the power
unit.
The power unit is
faulty:
● The DC bus
experiences
overvoltage.
Check whether a
same alarm is
generated for
multiple power units.
1. If multiple power
units generate a
same DC bus
overvoltage
alarm, check
whether UPS
output backfeed
exists.
2. If only one power
unit is faulty,
replace the power
unit.
3. If the fault cannot
be located,
contact Huawei
technical support.
UPS5000-A-(30 kVA-120 kVA)
User Manual 8 Troubleshooting
Issue 17 (2024-02-21) Copyright © Huawei Digital Power Technologies Co., Ltd. 156