CG-SVX06F-GB
42
Maintenance
Troubleshooting guide
These are simple diagnostic hints,
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 technician. If there is a
breakdown, the Trane Service office
should be contacted for confirmation
and assistance.
Problems symptoms
Problem causes
Action recommended
A) The compressor does not start up
Compressor terminals are live but motor does not start.
Motor burned out.
Replace compressor
Contactor motor not operational.
Coil burned out or broken contacts.
Repair or replace.
No current ahead of motor contactor.
a) Power cut.
b) Main power supply switched off.
Check fuses and connection.
See why system tripped.
If system is operational, switch on main power supply.
Current ahead of fuse, but not on contactor side.
Fuse blown.
Check motor insulation. Replace fuse.
Low voltage reading on voltameter.
Voltage too low.
Contact power Supply Utility.
Starter coil not excited.
Regulation circuit open.
Locate regulation device which has tripped out and see
why. See instructions concerning this device.
Compressor does not run.
Compressor motor “groans”.
High pressure switch tripped to contacts open on high
pressure.
Discharge pressure too high.
Compressor sticking (damaged or sticking components).
Discharge pressure too high
Shut down by thermal overload due to discharge
temperature or motor thermal overload
See “Discharge pressure too high”.
Wait 30 minutes until auto reset of compressor mounted
protection. Check superheat versus suction pressure or
water temperatures of operation.
B) Compressor stops
High pressure switch tripped.
Over current thermal relay tripped.
Motor temperature thermostat tripped.
Anti-freeze security tripped.
Discharge pressure too high.
a) Voltage too low.
b) Cooling demand too high, or condensing temperature
too high.
Not enough cooling fluid.
Water flow to evaporator too low.
See instructions for “discharge pressure high”.
a) Contact Power Supply Utility.
b) See instruction “discharge pressure too high”.
Repair leak. Add refrigerant.
Check water flow rate, and flow switch contact in water
C) Compressor stops just after its start
Suction pressure too low.
Filter drier iced up.
Filter drier clogged.
Replace filter drier.
D) The compressor keeps running without stopping
Temperature too high in areas requiring air-conditioning.
Excess load on cooling system.
Check thermal insulation and air-tightness of areas
requiring air-conditioning.
Chilled water temperature output too high.
Excess cooling demand on system.
Check thermal insulation and air-tightness of areas
requiring air-conditioning.
E) Loss of oil in compressor
Oil level too low in indicator.
Not enough oil.
Contact Trane office before to order oil
Gradual fall in oil level.
Filter drier clogged.
Replace filter drier.
Suction line too cold.
Compressor noisy
Liquid flows back to compressor.
Adjust superheat and check bulb fixing of the expansion
valve.
