Maintenance & Troubleshooting
Vertiv | Liebert CRD10 | User Manual
103
Symptom
Possible Causes
Items to be Checked or Handling Method
The suction and
discharge pressures
do not change after
startup
Either the Compressor is reversed or
the internal air tightness of the
compressor has failed
If the compressor is reversed, exchange any two L
lines of the compressor. If the internal air
tightness of the compressor has failed and cannot
be restored, replace the compressor
Low suction
pressure or liquid
returned
Insufficient refrigerant in the system
Check for leaks. Seal the leaking point and add the
refrigerant
Air filter too dirty
Replace the air filter
Filter drier clogged
Replace the filter drier
Improper superheating degree
Check the control board of the Electronic
Expansion Valve (EEV)
Sensing element of the electronic
expansion valve faulty
Replace the sensing element
Improper air flow distribution
Check the air supply and return system
Low condensing pressure
Check whether the condenser is faulty
Compressor too
noisy
Liquid returned
Refer to the handling methods of “Low suction
pressure or liquid returned”
Bearing worn out due to lubricant loss
Add lubricant
Compressor over
temperature
Too high compression ratio
Check the settings of the HP value and LP value,
and inspect if the condenser is clogged.
Check that the fans of the evaporator and
condenser are normal
Too high suction overheat degree
Add proper amount of refrigerant
