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UPS5000-A-(30 kVA-120 kVA)
User Manual
Case
Rectifier
abnormal
Issue 17 (2024-02-21)
Symptom
The rectifier of the
UPS power unit fails
to work, and the
UPS power unit
stops supplying
power.
Copyright © Huawei Digital Power Technologies Co., Ltd.
Possible Cause
The mains voltage
exceeds the upper
threshold 280 V or is
less than the lower
threshold 80 V.
The power unit is
faulty:
● PFC soft-startup
fails.
● The DC bus is
short-circuited.
● The rectifier
bridge current is
unbalanced.
● The input fuse is
broken.
● The discharger
SCR is short-
circuited and the
UPS transfers to
battery mode.
The power unit is
faulty:
● The DC bus
experiences
overvoltage.
8 Troubleshooting
Suggestion
Check whether the
mains voltage is
beyond the allowed
range. If so, contact
the electric power
company.
Replace the power
unit.
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.
156
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