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Table 57
UPS status messages (continued)
Event Message
Inverter Asynchronous
Inverter Fault
Fan Fault
Inverter STS (relay) Fail
Bypass STS Fail
Output Fuse Fail
Control Power 2 Fail
Unit Overload
System Overload
Unit Overload Timeout
Bypass Phase Reversed
Load Impact Transfer
Transfer Timeout
Load Sharing Fault
This alarm is triggered by an inverter software routine when the inverter and bypass waveforms
are misaligned by more than 6 degrees in phase. This alarm resets automatically once the
condition is no longer true.
1. First check if the alarm "Bypass unable to trace" or "Bypass abnormal" occurs. If so, solve it
first.
2. Verify the waveform of the bypass voltage. If it is too distorted, ask the customer to verify and
seek any possible measurements.
Contact Liebert Services at 800-543-2378 for assistance.
This alarm indicates a fault condition exists within the inverter.
Contact Liebert Services at 800-543-2378 for assistance.
At least one of the cooling fans failed. Contact Liebert Services at 800-543-2378 for assistance.
At least one of the static switches of inverter side is open or short circuit. This fault is locked until
power off. Contact Liebert Services for assistance at 800-543-2378 for assistance.
At least one of the static switches of bypass side is open or short circuit. This fault is locked until
power off.
Contact Liebert Services at 800-543-2378 for assistance.
At least one of the output fuses is open. Contact Liebert Services at 800-543-2378 for assistance.
Control Power 2 is abnormal or lost. Contact Liebert Services at 800-543-2378 for assistance.
The UPS is confirmed to be overload when the load arises above 105% nominal rating.
The alarm automatically resets once the overload condition is removed.
1. Confirm that the alarm is true by checking the load percent indicated on the LCD panel to
determine which phase is being overloaded.
2. If the alarm is true, measure the actual output current to verify that the indications are valid.
Disconnect unnecessary load and ensure the safety. In a parallel system, a severe load
sharing error can also leads to the alarm.
Contact Liebert Services at 800-543-2378 for assistance.
The UPS parallel system is confirmed to overload when the total load arises above 105% nominal
rating for the set basic number of UPSs. The alarm automatically resets once the overload
condition is removed.
1. Confirm that the alarm is true by checking the system load percent indicated on the LCD
panel to determine which phase is being overloaded.
2. If the alarm is true, measure the actual output current to verify that the indications are valid.
Disconnect unnecessary load and ensure the safety. In a parallel system, a severe load
sharing error can also leads to the alarm.
The UPS is confirmed to overload and the overload times out.
Note 1: The highest loaded phase will indicate overload timing-out first.
Note 2: When the timer is active, then alarm "unit overload" should also be active as the load is
above nominal.
Note 3: When the timer has expired, the inverter Static Switch is opened and the load transferred
to bypass. The inverter shutdown and will restart after 10 seconds.
Note 4: If the load decreases lower than 95% after 5 minutes, the system will transfer back to
inverter mode.
Confirm that the alarm is genuine by checking the load percent indicated on the LCD. If an
overload is indicated then check the load, and investigate any additional load connected prior to
the alarm (if applicable).
The phase sequence direction of bypass voltage is reversed.
Normally, the phase of Phase B lags 120 degrees behind Phase A, and the phase of Phase C
lags 120 degrees behind Phase B.
Verify that the phase rotation of the bypass supply presented to the UPS is correct, and rectify it if
it is found to be in error. Contact Liebert Services at 800-543-2378 for assistance.
A transfer to bypass occurred due to a large step load. The UPS should recover automatically.
Turn on connected equipment in sequential order to reduce the step loading of the inverter.
The load is on bypass power due to excessive number of transfers that occurred within the last
hour.
The UPS will recover automatically and will transfer the load back to inverter power within an
hour.
UPS working within a parallel system are not sharing load current correctly. Contact Liebert
Services at 800-543-2378 for assistance.
Description / Suggested Action (if any)
131
Maintenance
®
™
Liebert
APM
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