10
A. Compressor fails to start
B. Compressor stops
Problems and symptoms
High pressure control has cut out.
Thermal overload relay has cut out.
Winding thermostat has cut out.
Probable Cause
See H.
a)voltage too low
b) cooling load or condensing
temperature too high
Refrigerant shortage
Recommended action
See H.
a) contact power company.
b) see discharge pressure too.
high.
Repair leak, add refrigerant.
Problems and symptoms
Full voltage at motor terminal
but motor will not run.
Inoperative motor starter.
Open contacts of safety control of
thermal overload.
Electric circuit test shows no current
on line side of motor starter.
Electric circuit test show current
on line but not on motor side or fuse.
Voltmeter does not read proper
voltage.
Motor starter holding coil is not
energized.
Compressor will not operate.
Open contact on high pressure
switch.
Discharge pressure above cut-in
setting.
Probable cause
Burned-out motor.
Burned-out holding coil or broken
contacts.
Safety control of thermal overload
relays has cut outs.
a) Power failure.
b) Disconnect switch open.
Fuse down. Replace fuse
Low voltage
Open control circuit.
Frozen compressor due to locked
or damaged mechanism
Discharge pressure above cut-in
setting of high pressure cut-out
switch
Recommended action.
Repair or replace.
Repair or replace.
Call Trane Service.
Check for blown line fuse or
broken leak.
Determine why switch was
opened.
Check load on motor.
Call power company.
Locate open control and
determine cause.
See individual control.
Replace Compressor.
See Complaint<<Discharge
pressure too high.>>
Trouble Analysis
