CG-SVX01C-E4
31
Problems symptoms
D) The compressor keeps running
without stopping
Temperature too high in areas requiring air-
conditioning.
Chilled water temperature output too high.
E) Loss of oil in compressor
Oil level too low in indicator.
Gradual fall in oil level.
Suction line too cold.
Compressor noisy
F) Compressor noisy
Compressor knocks.
Suction duct abnormally cold.
G) Insufficient cooling capacity
Thermostatic expansion valve "whistles".
Excess pressure drops through filter drier
Excessive superheat.
Insufficient water flow.
H) Discharge pressure too high
Condenser abnormally hot.
Chilled water leaving temperature too high.
Condenser air output too hot.
I) Suction pressure too high
Compressor operates continuously.
Suction duct abnormally cold.
Refrigerant flows back to compressor.
J) Suction pressure too low
Excessive pressure drop through filter drier.
Refrigerant does not flow through
thermostatic expansion valve.
Loss of power.
Superheat too low.
K) Insufficient cooling capacity
Low pressure drops through evaporator
Problem cause
Excess load on cooling system.
Excess cooling demand on system.
Not enough oil.
Filter drier clogged.
Liquid flows back to compressor.
Components broken in compressor.
a) Uneven liquid flow.
b) Expansion valve locked in open position.
Not enough refrigerant.
Drier filter clogged.
Superheat not properly adjusted.
Chilled water pipes obstructed.
Presence of uncondensable liquids in system,
or excess refrigerant.
Overload on cooling system.
Reduced air flow. Air intake temperature higher
than specified for unit
Excess cooling demand on evaporator
a) Expansion valve too far open.
b) Expansion valve locked in open position.
Filter drier clogged.
Expansion valve bulb has lost its refrigerant.
Expansion valve obstructed.
Excessive pressure drops through evaporator.
Low water flow rate.
Action recommended
Check thermal insulation and air-tightness of
areas requiring air-conditioning.
Check thermal insulation and air-tightness of
areas requiring air-conditioning.
Contact Trane office before to order oil
Replace filter drier.
Adjust superheat and check bulb fixing of the
expansion valve.
Change compressor.
a) Check superheat setting and fixing
of expansion valve bulb.
b) Repair or replace.
Check refrigerant circuit tightness and add
refrigerant.
Replace.
Check adjustment of superheat and adjust
thermostatic expansion valve.
Clean pipes and strainer.
Purge uncondensable fluids and drain off
excess refrigerant.
Reduce load on system.
Reduce water flow if necessary.
Clean or replace air filters. Clean coil. Check
operation of motor fans.
Check system.
a) Check for superheat and check that
expansion valve bulb is secure.
b) Replace.
Replace the filter drier.
Replace the bulb.
Replace.
Check adjustment of superheat and adjust
thermostatic expansion valve.
Check water flow rate. Check state of strainer,
check for obstruction in chilled water pipes.
Check pressure switch contact in water.
Caution:
The above is not a comprehensive analysis of the Scroll compressor refrigeration system. The aim is to give operators
simple instructions on basic unit processes so that they have the technical knowledge to identify and bring defective
operations to the notice of qualified technicians.
Troubleshooting guide
