Liebert ITA UPS 16kVA User Manual page 38

30 Chapter 3 Operation And Display Panel
Alarm message
Rectifier over-current
Soft start fail
Bypass unable to
trace
Bypass protection
Inverter asynchronous
Inverter fault
Inverter overtemp.
Fan fault
Inverter STS fail
Bypass STS fail
Operation invalid
Neighbor bypass
SSTS fail
Output fuse fail
Unit over load
Byp. abnormal
shutdown
Inverter over current
Bypass phase reverse
Load impact transfers
bypass
Transfer time-out
Bus abnormal
Rectifier is over current
Rectifier could not start due to low DC bus voltage
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 ±10% rating.
This alarm will automatically recover when the bypass voltage goes normal.
1. First verify that the bypass voltage and frequency displayed on the operator control and display panel
is within the selected range. Note that the rated voltage and frequency are specified by the 'Output
Voltage Level' and 'Output Frequency Level' respectively.
2. If the displayed voltage is abnormal, please verify the actual bypass voltage and frequency presented
to the UPS. Check the external power if it is found to be faulty
This alarm is triggered by an inverter software program when the amplitude or frequency of bypass
voltage is too high or too low. The amplitude threshold is fixed for ±10% rating. This alarm will
automatically recover when the bypass voltage goes normal.
1. First check if there are some relevant alarms, such as 'Bypass Phase Reverse', 'Input disconnect
Fault'. If so, solve them first.
2. Then verify that the bypass voltage and frequency displayed on the LCD are within the limit. Note that
the rated voltage and frequency are specified by the 'Output Voltage Level' and 'Output Frequency
Level' respectively.
3. If the displayed voltage is abnormal, please verify the actual bypass voltage and frequency presented
to the UPS. Check the external power 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 user feedback
This alarm is triggered by an inverter software program when the inverter and bypass waveforms are
misaligned by more than 6 degrees in phase. The amplitude threshold is fixed for ±10% rating. This
alarm will recover automatically when the alarm condition disappears.
1. First check if the alarm 'Bypass Unable To Trace' or 'Bypass Protection'. If so, solve it first.
2. Verify the waveform of the bypass voltage. If it is too distorted, ask the user to verify it and seek any
possible measurement
Inverter output voltage beyond limits. Load transfers to bypass
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 5 minutes delay from the disappearance of the overtemperature signal. If the
overtemperature condition is true, check the following items:
1. high ambient temperature. 2. blocked cooling airway. 3. any fan failure. 4. prolonged inverter overload
At least one of the cooling fans has failed
At least one of the static switches of inverter side is open or short circuit. This fault is locked until power
off
At least one of the static switches of bypass side is open or short circuit. This fault is locked until power
off
Incorrect operation
At least one of the static switches of single bypass side in parallel systemis open or short circuit. This
fault is locked until power off
At least one inverter output fuse blowou. The inverter shuts down, the load transfers to bypass
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 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.
Both bypass and inverter voltages unavailable. Load interruption
Inverter pulse width modulation module overloaded
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
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
DC input voltage to inverter beyond limits. Inverter shuts down. Load transfers to bypass
Liebert ITA 16kVA/20kVA User Manual
Description