Emerson Liebert NX 480V User Manual
Page 102
UPS Status Messages
94
Bypass Unable to Trace
This alarm is triggered by an inverter software routine when the amplitude or frequency of
bypass voltage is beyond the normal range.
The amplitude threshold is fixed for positive and negative 10% rating.
This alarm automatically resets once the bypass voltage goes normal.
First verify that the bypass voltage and frequency displayed on the panel is within the selected
range. Note here the rated voltage and frequency are specified by “Output voltage level” and
“Output frequency level” respectively.
If the displayed voltage is believed to be abnormal, then verify the bypass voltage and frequency
presented to the UPS. Check the external supply if it is found to be faulty.
Contact Liebert Global Services at 800-543-2378 for assistance.
Bypass Abnormal
This alarm is triggered by an inverter software routine when the amplitude or frequency of
bypass voltage exceeds the limit.
This alarm automatically resets once the bypass voltage goes normal.
First check whether there are relevant alarms such as “Bypass disconnect open,” “Bypass
phase reverse” and “Mains neutral lost.” If they appear, solve them first.
Then verify that the bypass voltage and frequency displayed on the panel is within the bypass
limit. Note here the rated voltage and frequency are specified by “Output voltage level” and
“Output frequency level” respectively.
If the displayed voltage is believed to be abnormal, then verify the bypass voltage and frequency
presented to the UPS. Check the external bypass supply if it is found to be faulty. If the utility is
likely to trigger this alarm frequently, the bypass limit can be increased through the configuration
software according to the customer’s agreement.
Contact Liebert Global Services at 800-543-2378 for assistance.
Inverter Asynchronous
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 clears.
First check if the alarm “Bypass unable to trace” or “Bypass abnormal” occurs. If so, solve it first.
Verify the waveform of the bypass voltage.
Contact Liebert Global Services at 800-543-2378 for assistance.
Inverter Fault
This alarm indicates a fault condition exists within the inverter.
Contact Liebert Global Services at 800-543-2378 for assistance.
Output Voltage Abnormal
This alarm indicates the inverter voltage waveform is abnormal.
Contact Liebert Global Services at 800-543-2378 for assistance.
Input Current Abnormal
This alarm indicates the rectifier input current is abnormal.
Contact Liebert Global Services at 800-543-2378 for assistance.
Inv. Inductor Overtemp.
The temperature of the inverter filter inductor or inverter common mode inductor is too high to
keep inverter running.
This alarm is triggered by the signal from a thermostat mounted in the inverter filter inductor.
The UPS would recover automatically after a 5 minute delay from the disappearance of the
overtemperature signal.
If the overtemperature condition is true then check for and verify:
High ambient air temperature.
Blocked cooling airway
Any fan failure
Prolonged inverter overload.
Contact Liebert Global Services at 800-543-2378 for assistance.
Inverter Overtemp.
The temperature of the inverter heat sink is too high to keep inverter running.
This alarm is triggered by the signal from a temperature monitoring thermostat on the inverter
bridge heat sink.
The UPS will recover automatically after a 5 minute delay from the disappearance of the
overtemperature signal.
If the overtemperature condition is true then check for and verify:
high ambient air temperature.
blocked cooling airway.
any fan failure.
prolonged inverter overload.
Contact Liebert Global Services at 800-543-2378 for assistance.
Fan Fault
At least one of the cooling fans has failed. Contact Liebert Global Services at 800-543-2378 for
assistance.
Table 36
UPS status messages
Event Message
Description / Suggested Action (if any)