Emerson Liebert NX 10-30kVA - Manual (Page 106)

UPS Status Messages
98
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.
1. 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.
2. 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 if there are some relevant alarms such as “Bypass disconnect open”, “Bypass phase
reverse” and “Mains neutral lost”. If they appear, solve them first.
1. 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.
2. 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 changed a little larger
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 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 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.
Inv. Inductor Overtemp.
The temperature of the output filter inductor is too high to keep inverter running.
This alarm is triggered by the signal from a thermostat mounted in the output 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:
1. high ambient air temperature.
2. blocked cooling airway.
3. any fan failure.
4. 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:
1. high ambient air temperature.
2. blocked cooling airway.
3. any fan failure.
4. prolonged inverter overload.
Contact Liebert Global Services at 800-543-2378 for assistance.
Fan Fault
At least one of the cooling fans fails. Contact Liebert Global Services at 800-543-2378 for
assistance.
Inverter STS Fail
At least one of the static switches of inverter side is open or short circuit. This fault is locked until
power off. Contact Liebert Global Services for assistance at 800-543-2378 for assistance.
Bypass STS Fail
At least one of the static switches of bypass side is open or short circuit. This fault is locked until
power off.
Contact Liebert Global Services at 800-543-2378 for assistance.
Table 44 UPS status messages (continued)
Event Message Description / Suggested Action (if any)