Carrier 040-420 - Manual (Page 67)

SYMPTOMS
COMPRESSOR DOES
NOT RUN
COMPRESSOR CYCLES OFF
ON LOW PRESSURE
COMPRESSOR SHUTS DOWN
UNIT OPERATES LONG OR
CONTINUOUSLY
SYSTEM NOISES
COMPRESSOR LOSES OIL
FROSTED SUCTION LINE
HOT LIQUID LINE
FROSTED LIQUID LINE
COMPRESSOR DOES NOT
UNLOAD
DOES NOT
Table Troubleshooting
CAUSE
Power line open
Control fuse open
High Pressure Switch (HPS)
tripped
Tripped power breaker
L o o s e t e r m i n a l c o n n e c t i o n
Improperly wired controls
Low line voltage
Compressor motor defective
Seized compressor
Loss of charge
Bad transducer
Low refrigerant charge
High-pressure control erratic in action
Compressor discharge valve partially closed
Condenser fan(s) not operating
Condenser coil or
Low refrigerant charge
Control contacts fused
plugged or plugged expansion
valve or filter driver
D e f e c t i v e i n s u l a t i o n
Service load
Piping vibration
Expansion valve hissing
Compressor noisy
Leak in system
Mechanical damage (blown piston or
broken discharge valve)
Crankcase heaters not energized
durina shutdown
Expansion valve admitting excess
refrigerant
Shortaae of refriaerant due to leak
Shutoff valve partially closed or restricted
B u r n e d o u t c o i l
Defective capacity control valve
M i s w i r e d s o l e n o i d
Weak, broken, or wrong valve body spring
M i s w i r e d s o l e n o i d
Defective capacity control valve
Plugged strainer (high side)
Stuck or damaged unloader piston or
piston ring(s)
REMEDY
Reset circuit breaker
Check control circuit for ground or short.
R e p l a c e f u s e
Move LOCAL/ENABLE-STOP-CCN switch to STOP
position then back to RUN or CCN position.
Check the controls. Find cause of trip
and reset breaker
Check connections
Check wiring and rewire.
Check line voltage. Determine location
of voltage drop and remedy deficiency
Check motor winding for open or shot-t.
Replace compressor if necessary.
Replace compressor.
Repair leak and recharge
Replace transducer.
Add refrigerant.
Replace control
Open or replace if defective.
Check wiring. Repair or replace motor(s)
i f d e f e c t i v e .
C l e a n c o i l .
Add refrigerant,
Replace control
Clean or replace
Replace or repair.
Keep doors and windows closed.
Check valves. Replace if necessary.
Support piping as required
Add refrigerant.
Check for plugged liquid line filter drier.
Check valve plates for valve noise.
Replace compressor (worn bearings).
Check for loose compressor bolts.
Repair leak.
Repair damage or replace compressor.
Replace heaters, check wiring and
crankcase heater relay contacts.
Check cooler and compressor thermistors.
T e s t E X V .
Repair leak and recharge
Open valve or remove restriction.
R e p l a c e c o i l
Replace valve
Rewire correctly.
R e p l a c e s p r i n g
Rewire correctly
Replace valve.
Clean or replace strainer.
Clean or replace the necessary parts.