Carrier 48SS018-060, 48SX024-060 user manual Troubleshooting, Cooling

TROUBLESHOOTING

Cooling

SYMPTOM	CAUSE	REMEDY
Compressor and	Power failure	Call power company.
condenser fan will
	Fuse blown or circuit breaker tripped	Replace fuse or reset circuit breaker.
not start.
	Defective thermostat, contactor, transformer,	Replace component.
	or control relay
	Insufficient line voltage	Determine cause and correct.
	Incorrect or faulty wiring	Check wiring diagram and rewire correctly.
	Thermostat setting too high	Lower thermostat setting below room temperature.
Compressor will not	Faulty wiring or loose connections in	Check wiring and repair or replace.
start but condenser	compressor circuit
fan runs.
	Compressor motor burned out, seized, or	Determine cause. Replace compressor.
	internal overload open
	Defective run/start capacitor, overload,	Determine cause and replace.
	start relay
	One leg of 3-phase power dead	Replace fuse or reset circuit breaker.
		Determine cause.
Three-phase scroll	Scroll compressor is rotating in the	Correct the direction of rotation by reversing the
compressor (Units	wrong direction	3-phase power leads to the unit. Shut down unit to
48SS048,060 and		allow pressures to equalize.
48SX036-060 only)
makes excessive
noise, and there
may be a low pres-
sure differential.
Compressor cycles	Refrigerant overcharge or undercharge	Recover refrigerant, evacuate system, and
(other than normally		recharge to capacities shown on nameplate.
satisfying
	Defective compressor	Replace and determine cause.
thermostat).
	Insufficient line voltage	Determine cause and correct.
	Blocked condenser	Determine cause and correct.
	Defective run/start capacitor, overload	Determine cause and replace.
	or start relay
	Defective thermostat	Replace thermostat.
	Faulty condenser-fan motor or capacitor	Replace.
	Restriction in refrigerant system	Locate restriction and remove.
Compressor	Dirty air ®lter	Replace ®lter.
operates
	Unit undersized for load	Decrease load or increase unit size.
continuously.
	Thermostat set too low	Reset thermostat.
	Low refrigerant charge	Locate leak, repair, and recharge.
	Leaking valves in compressor	Replace compressor.
	Air in system	Recover refrigerant, evacuate system, and recharge.
	Condenser coil dirty or restricted	Clean coil or remove restriction.
Excessive head	Dirty air ®lter	Replace ®lter.
pressure.
	Dirty condenser coil	Clean coil.
	Refrigerant overcharged	Recover excess refrigerant.
	Air in system	Recover refrigerant, evacuate system, and recharge.
	Condenser air restricted or air short-cycling	Determine cause and correct.
Head pressure too	Low refrigerant charge	Check for leaks, repair and recharge.
low.
	Compressor valves leaking	Replace compressor.
	Restriction in liquid tube	Remove restriction.
Excessive suction	High heat load	Check for source and eliminate.
pressure.
	Compressor valves leaking	Replace compressor.
	Refrigerant overcharged	Recover excess refrigerant.
Suction pressure	Dirty air ®lter	Replace ®lter.
too low.
	Low refrigerant charge	Check for leaks, repair and recharge.
	Metering device or low side restricted	Remove source of restriction.
	Insufficient evaporator air¯ow	Increase air quantity. Check ®lter Ð replace if
		necessary.
	Temperature too low in conditioned area	Reset thermostat.
	Outdoor ambient below 40 F	Install low-ambient kit.
	Field-installed ®lter-drier restricted	Replace.

48