Maintenance & Troubleshooting
Vertiv | Liebert CRD10 | User Manual
102
7.12.2
Troubleshooting of Compressor and Cooling System
Table 7-5 Troubleshooting the Cooling System
Symptom
Possible Causes
Items to be Checked or Handling Method
Compressor can’t be
started
Does not power-on (shutdown)
Check the main power against under-voltage,
over-voltage, and phase loss
MCB and contactor faulty
Check the compressor MCB, contactor, and
connecting cables
Alarm lock
View the unit alarm records, replace the
damaged component and power it on again
Compressor coils shorted and burnt
Check the motor and replace it in case of any
defects or malfunction
The Contactor does not
get closed, and the
compressor does not
start
Low discharging overheat degree alarm
Check the state of the micro-processing
controller
High pressure MCB action
Check if there is an HP alarm.
Discharging temperature alarm
Check whether a discharging low/high
temperature alarm exists
Low pressure alarm
View if a low-pressure alarm exists in the history
alarm
Contactor faulty
Check if the contactor is able to energize.
Compressor driver faulty
Check the compressor driver
The Compressor
stops after running
for 3 minutes.
Contactor open
Refrigerant leaked, the low-pressure
check is too low or abnormal
Check the suction pressure
Check the circuit of the low-pressure sensor
Calibrate accordingly so that the low-pressure
sensor reader is within ±0.3 bar range of the actual
pressure
High pressure protection
Condenser clogged
Clean the condenser
Condenser system does not start
Check the condenser fan for the air-cooled system
Too much refrigerant has been charged
Check whether the sub-cooling degree is too high
Low discharge pressure
Refrigerant leaked
Locate the leakage point, repair it and add the
refrigerant
The Fan speed controller of the outdoor
unit is faulty, while the output voltage
remains 100%, irrespective of the
change in the condensing pressure
If the fan speed controller is found faulty, then it
has to be replaced