Trouble Shooting - Carrier 42QH30-H Service Maintenance Manual

17. TROUBLE SHOOTING

TROUBLE
Compressor and outdoor fan will not
start
Compressor will not start, but outdoor
fan runs
Compressor runs bur cycles on
internal overload (other than normally
satisfying thermostat)
Compressor operates continuously
Excessive head pressure
REASON
Power failure
Fuse blown or / and circuit breaker tripped
Detective contactor
Low line voltage
Incorrect or loose wiring
Temp. setting too low
Faulty wiring or loose connections in
compressor circuit
Compressor motor burned out, stuck or
internal over-load open
Detective run capacitor
Refrigerant over or under charge
Air or non condensable refrigerant in
system
Detective compressor
Low or too high line voltage
Blocked outdoor coil
Outdoor fan stopped
Detective run capacitor
Faulty fan motor of outdoor section
Restriction in refrigerant system
Capillary or Accurate restricted or ice
clogged.
System undersized for load
Temp. setting too low
Defective outdoor fan
Air or non condensable refrigerant in
system
Air restricted or indoor section filter dirty
Dirty outdoor coil
Detective outdoor fan
Refrigerant over charged
Air or non condensable refrigerant in
system
Outdoor section air restricted
18
ACTION
Call power company
Replace fuse or reset circuit breaker
Replace
Determine cause and eliminate
Check wiring diagram and rewire correctly
Reset temp. setting
Check wiring and repair or correct
Replace compressor and determine cause
Replace
Blow refrigerant, evacuate system and
recharge
Blow refrigerant, evacuate system and
recharge
Replace and determine cause
Determine cause and correct
Determine cause and replace
Determine cause and replace
Replace
Replace
Locate restriction and remove
Blow refrigerant, evacuate system and
recharge
Decrease load or increase system size
Reset temp. setting
Check for source and replace
Blow refrigerant, evacuate system and
recharge
Clean filter or remove restriction
Clean coil
Replace
Purge excess refrigerant
Blow refrigerant, evacuate system and
recharge
Remove restriction