TP48200E-H12C1 (Nepal, Ncell)
User Manual
4 Maintenance
Issue 01 (2015-05-05)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
19
4.2.3 AC Under Volt
Possible Causes
The AC undervoltage alarm threshold is not set properly on the SMU.
The power grid is faulty.
Measures
1.
Check whether the AC undervoltage alarm threshold is properly set. If no, adjust it to a
proper value.
2.
Check whether the AC input voltage is below the AC undervoltage alarm threshold (180
V AC by default). If yes, handle the AC input fault.
4.2.4 Phase A/B/C Failure
Possible Causes
The AC input power cable is faulty.
The rectifier is in poor contact.
The monitoring unit is faulty.
Measures
1.
Check whether the AC input power cable is correctly and securely installed. If no,
reinstall the cable. If the insulation layer deteriorates, replace the cable.
2.
Check whether a short circuit occurs in the AC input power cable or the insulation layer
is damaged. If yes, replace the cable.
3.
If the AC input is normal and the Alarm indicators on certain rectifiers are steady yellow,
reinstall the rectifiers.
4.
If the alarm persists, replace the monitoring unit.
4.2.5 DC Over Volt
Possible Causes
The DC overvoltage alarm threshold is not set properly on the SMU.
The power system voltage is set too high in manual mode.
Rectifiers are faulty.
Measures
1.
Check whether the DC overvoltage alarm threshold (58 V DC by default) is properly set.
If no, adjust it to a proper value.
2.
Check whether the system voltage is set too high in manual mode. If yes, confirm the
reason and adjust the voltage to normal after the operation.
3.
Remove the rectifiers one by one and check whether the alarm is cleared. If the alarm
still exists, reinstall the rectifier. If the alarm is cleared, replace the rectifier.