Emerson 480V Manuel D’Utilisation

Table 39 shows all event messages as they appear in the current status area of the LCD and in the 

history log, along with a description and recommended actions, if any. For further information on the 

current status area and the history log, see 2.11 UPS Status Messages.

Inverter Comm. Fail

The RS-485 communication between internal monitor and inverter has failed. Contact Liebert 

Services at 800-543-2378 for assistance.

Rectifier Comm. Fail

The RS-485 communication between internal monitor and rectifier fails. Contact Liebert 

Services at 800-543-2378 for assistance.

Parallel Comm. Fail

The CAN communication between different UPS units within a parallel system has failed.

Check if there are some UPS units not powered on in the parallel system. If so, power on these 

UPS units and check if the alarm disappears.

Press Fault Clear push button.

If alarm does not clear, contact Liebert Services at 800-543-2378

Battery Overtemp.

The battery temperature is over limit. Check the battery temperature and ventilation

Ambient Overtemp.

The ambient temperature is over limit. Check the ventilation of UPS room.

Replace Battery

Battery should be replaced. Contact Liebert Services at 800-543-2378 for assistance.

Battery Low Pre-warning

Before the end of discharging, battery under-voltage pre-warning should occur. After this pre-

warning, battery should have the capacity for 3 minutes discharging with full load. The time is 

user configured from 3 to 60 minutes.

Shut down the load in time to prevent damage to equipment and data.

Battery End of Discharge

Inverter turned off due to low battery voltage.

Check the utility failure and try to recover it.

Mains Volt. Abnormal

Mains voltage exceeds the upper or lower limit and results in rectifier shutdown.

Check the input line-to-line voltage amplitude of rectifier.

Mains Undervoltage

Mains voltage is undervoltage 288V~384V line to line voltage with derated load.

Check the input line-to-line voltage amplitude of rectifier.

Mains Freq. Abnormal

Mains frequency is out of limit range and results in rectifier shutdown.

Check the rectifier’s input voltage frequency

Rectifier Fault

Contact Liebert Services at 800-543-2378 for assistance.

Input Inductor Overtemp.

The temperature of rectifier inductor of rectifier common mode inductor is too high to keep the 

rectifier running.

Check the ambient temperature and ventilation; contact Liebert Services at 800-543-2378 for 

assistance.

Rectifier Overtemp.

The temperature of the heat sink is too high to keep the rectifier running.

The UPS can recover automatically. Check the environment and ventilation.

Charger Fault

The charger has a fault. Contact Liebert Services at 800-543-2378 for assistance.

Control Power 1 Fail

Control Power 1 has failed or has been lost. Contact Liebert Services at 800-543-2378 for 

assistance.

Mains Phase Reversed

Input phase sequence is inverse. Contact Liebert Services at 800-543-2378 for assistance.

Rectifier Overcurrent

The current of rectifier is over limit. Contact Liebert Services at 800-543-2378 for assistance.

Soft Start Fail 

Rectifier could not start due to low DC bus voltage. Contact Liebert Services at 800-543-2378 

for assistance.

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 Services at 800-543-2378 for assistance.