Carrier 50SX024-060, 50SS018-060 owner manual Troubleshooting Cooling Chart, Symptom Cause Remedy

TROUBLESHOOTING COOLING CHART

SYMPTOM	CAUSE	REMEDY
Compressor and con-	Power failure	Call power company.
denser fan will not
	Fuse blown or circuit breaker tripped	Replace fuse or reset circuit breaker.
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.
	Single-phase units with scroll compressor	DO NOT bypass this compressor time delay Ð wait
	(50SS048,060 and 50SX) have a 5-minute time delay	for 5 minutes until time-delay relay is deenergized.
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.
	or 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	wrong direction	3-phase power leads to the unit.
(50SS048, 060;
50SX036-060
units only) makes ex-
cessive noise, and
there may be a low
pressure differential.
Compressor cycles	Refrigerant overcharge or undercharge	Reclaim refrigerant, evacuate system, and recharge
(other than normally		to capacities shown on nameplate.
satisfying thermostat).
	Defective compressor	Replace and determine cause.
	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 operates	Dirty air ®lter	Replace ®lter.
continuously.	Unit undersized for load	Decrease load or increase unit size.
	Thermostat set too low	Reset thermostat.
	Low refrigerant charge	Locate leak, repair and recharge.
	Leaking valves in compressor	Replace compressor.
	Air in system	Reclaim 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	Reclaim excess refrigerant.
	Air in system	Reclaim refrigerant, evacuate system and recharge.
	Condenser air restricted or air short-cycling	Determine cause and correct.
Head pressure too low.	Low refrigerant charge	Check for leaks, repair and recharge.
	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	Reclaim excess refrigerant.
Suction pressure too	Dirty air ®lter	Replace ®lter.
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.

42