Troubleshooting Cooling Chart - Carrier 50SS018-060 Installation, Start-Up And Service Instructions Manual

SYMPTOM
Compressor and con- Power failure
denser fan will not
Fuse blown or circuit breaker tripped
start.
Defective thermostat, contactor, transformer,
or control relay
Insufficient line voltage
Incorrect or faulty wiring
Thermostat setting too high
Single-phase units with scroll compressor
(50SS048,060 and 50SX) have a 5-minute time delay
Compressor will not Faulty wiring or loose connections in
start but condenser compressor circuit
fan runs.
Compressor motor burned out, seized, or
internal overload open
Defective run/start capacitor, overload,
or start relay
One leg of 3-phase power dead
Three-phase scroll Scroll compressor is rotating in the
compressor wrong direction
(50SS048, 060;
50SX036-060
units only) makes ex-
cessive noise, and
there may be a low
pressure differential.
Compressor cycles Refrigerant overcharge or undercharge
(other than normally
satisfying thermostat).
Defective compressor
Insufficient line voltage
Blocked condenser
Defective run/start capacitor, overload
or start relay
Defective thermostat
Faulty condenser-fan motor or capacitor
Restriction in refrigerant system
Compressor operates Dirty air filter
continuously.
Unit undersized for load
Thermostat set too low
Low refrigerant charge
Leaking valves in compressor
Air in system
Condenser coil dirty or restricted
Excessive head Dirty air filter
pressure.
Dirty condenser coil
Refrigerant overcharged
Air in system
Condenser air restricted or air short-cycling
Head pressure too low. Low refrigerant charge
Compressor valves leaking
Restriction in liquid tube
Excessive suction High heat load
pressure.
Compressor valves leaking
Refrigerant overcharged
Suction pressure too Dirty air filter
low.
Low refrigerant charge
Metering device or low side restricted
Insufficient evaporator airflow
Temperature too low in conditioned area
Outdoor ambient below 40 F
Field-installed filter-drier restricted

TROUBLESHOOTING COOLING CHART

CAUSE
42
REMEDY
Call power company.
Replace fuse or reset circuit breaker.
Replace component.
Determine cause and correct.
Check wiring diagram and rewire correctly.
Lower thermostat setting below room temperature.
DO NOT bypass this compressor time delay — wait
for 5 minutes until time-delay relay is deenergized.
Check wiring and repair or replace.
Determine cause. Replace compressor.
Determine cause and replace.
Replace fuse or reset circuit breaker.
Determine cause.
Correct the direction of rotation by reversing the
3-phase power leads to the unit.
Reclaim refrigerant, evacuate system, and recharge
to capacities shown on nameplate.
Replace and determine cause.
Determine cause and correct.
Determine cause and correct.
Determine cause and replace.
Replace thermostat.
Replace.
Locate restriction and remove.
Replace filter.
Decrease load or increase unit size.
Reset thermostat.
Locate leak, repair and recharge.
Replace compressor.
Reclaim refrigerant, evacuate system and recharge.
Clean coil or remove restriction.
Replace filter.
Clean coil.
Reclaim excess refrigerant.
Reclaim refrigerant, evacuate system and recharge.
Determine cause and correct.
Check for leaks, repair and recharge.
Replace compressor.
Remove restriction.
Check for source and eliminate.
Replace compressor.
Reclaim excess refrigerant.
Replace filter.
Check for leaks, repair and recharge.
Remove source of restriction.
Increase air quantity. Check filter — replace if
necessary.
Reset thermostat.
Install low-ambient kit.
Replace.