Carrier BT30RF- EXPR Service & Installation Manual page 94

COMPRESSOR – TROUBLESHOOTING CHARTS
TROUBLE
WON'T START. NO HUM.
WON'T START. HUMS
INTERMITTENTLY.
(cycling on protector)
COMPRESSOR STARTS –
MOTOR WON'T GET OFF
STARTING WINDING.
96
COMMON CAUSE
Open line circuit.
Protector open.
Control contacts open.
Open circuit in stator.
Improperly wired.
Low line voltage.
Open starting capacitor.
Relay contacts not closing.
Open circuit in start winding.
Stator winding grounded (normally
will blow fuse.)
High discharge pressure.
Tight compressor.
Weak starting capacitor or one weak
capacitor of a set.
Low line voltage.
Improperly wired.
Defective relay.
Running capacitor shorted.
Starting and running windings shorted.
Starting capacitor weak or one of a
set open.
High discharge pressure.
Tight compressor.
REMEDY
Check wiring, fuses, receptacle.
Wait for reset—check current.
Check control, check pressures.
Replace stator or compressor.
Check wiring against diagram.
Check main line voltage, determine location of
voltage drop.
Replace starting capacitor.
Check by operating manually. Replace relay if
defective.
Check stator leads. If leads are all right,
replace compressor.
Check stator leads. If leads are all right
replace compressor.
Eliminate cause of excessive pressure. Make
sure discharge shut-off and receiver valves
are open if applicable.
Check oil level – correct binding condition, if
possible. If not, replace compressor.
Replace.
Bring up voltage.
Check wiring against diagram.
Check operation – replace relay if defective.
Check resistances. Replace capacitor if
defective.
Check capacitance – replace if defective.
Check capacitance. Replace if defective.
Check discharge shutoff valves.
Check pressure.
Check oil level. Check binding. Replace
compressor if necessary.
TROUBLESHOOTING