Vertiv | Liebert PEX4 | User Manual
81
Troubleshooting
Symptom
Potential Causes
Items to be Checked or Handling Process
Contactor did
not close and
compressor is
not running
Compressor Contactor
fault
•
Check if contactor is functioning.
•
Check if there is 24 Vdc between J18-3 (compressor 1) and
terminal G. And also of J20-1 (compressor 2) and terminal G.
Suction temperature
sensor fault
•
Check if the wiring of sensor is connected to controller.
•
Check if there is suction temperature sensor failure or the
readings are in normal range.
Low pressure sensor
fault
•
Check if the wiring of sensor is connected to controller.
•
Check if there is low pressure sensor failure or the readings are in
normal range.
Drive fault
•
Check if the wiring of compressor drive is normal.
•
Check if the current is too large.
•
Check if the proper ventilation is available to the drive.
EEV fault
•
Check if the wiring of EEV board is normal.
•
Check the EEV fault code and replace the EEV board.
Drive communication
fault
Check the inverter 458 communication line wiring is intact, and then
re-power, reset or eliminate this alarm on HMI panel.
Circuit breaker tripped
Check the line voltage after checking the circuit breaker and contactor.
Built-in protection
of the compressor is
disconnected
Check if the compressor windings are open. If open, wait for its
automatic reset after cools down.
Detecting the discharge
gas temperature sensor
Check if there is high discharge temperature alarm or low discharge
temperature superheat alarm in alarm history list.
Detecting a low-
pressure sensor
Check if there is low-pressure alarm in the alarm view history.
Suction temperature
sensor fault
•
Check if the wiring of sensor is connected to controller.
•
Check if there is suction temperature sensor failure or the readings
are in normal range.
Low pressure sensor
fault
•
Check if the wiring of sensor is connected to controller.
•
Check if there is low pressure sensor failure or the readings are in
normal range.
Drive fault
•
Check if the wiring of compressor drive is normal.
•
Check if the current is too large.
•
Check if the drive gets proper ventilation.
Drive communication
fault
Check the inverter 458 communication line wiring is intact, and then
re-power on reset or eliminate this alarm on HMI panel.
EEV fault
•
Check if the wiring of EEV board is normal.
•
Check the EEV fault code and replace the EEV board.
Compressor
operation
stopped for 5
minutes
Refrigerant leakage, too
low voltage detection/
abnormality
•
Check the suction pressure.
•
Check the wiring of low-pressure sensor.
•
Check if the differentiation between low pressure sensor reading
and the actual pressure are within ± 0.3 bar (high and low pressure
sensor values can be read in service tool, referred in gauge
pressure).
