Carrier 38GNA - Manual (Page 7)

Trouble Analysis Chart
SYMPTOM CAUSE REMEDY
Compressor and condenser fan do
not start
Power failure Call power company
Fuse blown or circuit breaker tripped Replace fuse or reset circuit breaker
Defective thermostat contactor or con­
trol relay
Replace component
Low-line voltage Determine cause and correct
Incorrect or faulty wiring
Check wiring diagram and rewire cor­
rectly
Thermostat setting too high
Lower thermostat setting below room
temperature
Compressor does not start, but con­
denser fan runs
Faulty wiring or loose connections in
compressor circuit
Check wiring; repair or replace
Compressor motor burned out, seized,
or internal overload open Replace compressor and determine
cause
Defective run capacitor Determine cause and replace
Compressor cycles (other than nor­
mally satisfying thermostat)
Refrigerant overcharged or under­
charged
Remove refrigerant, evacuate system,
and recharge
Defective compressor Determine cause and replace
Low-line voltage Determine cause and correct
Blocked condenser Determine cause and correct
Defective run capacitor Determine cause and replace
Defective thermostat Replace thermostat
Faulty condenser fan motor or capacitor Replace
Restriction in refrigerant system Locate restriction and remove
Compressor operates continuously
Unit undersized for load Decrease load or increase unit size
Thermostat setting too low
Raise thermostat setting above room
temperature
Low refrigerant charge Locate leak; repair and recharge
Leaking valves in compressor Replace compressor
Air in system
Remove refrigerant, evacuate system,
recharge
Condenser coil dirty or restricted Clean coil or remove restriction
Excessive head pressure
Dirty condenser coil Clean coil
Refrigerant overcharged Remove excess refrigerant
Air in system
Remove refrigerant, evacuate system,
and recharge
Condenser air restricted or air short cy­
cling
Eliminate cause
Head pressure too low
Low refrigerant charge Locate leak; repair and recharge
Compressor valves leaking Replace compressor
Restriction in liquid tube Remove restriction
Excessive suction pressure
High-heat load Check for source and eliminate
Compressor valves leaking Replace compressor
Refrigerant overcharged Remove excess refrigerant
Suction pressure too low
Low refrigerant charge Locate leak; repair and recharge
Metering device or low side restricted Remove source or restriction
Low evaporator air Increase air
Temperature too low in conditioned
area
Reset thermostat