Carrier 50TFQ004 Installation, Start-Up And Service Instructions Manual page 50

PROBLEM
Compressor and Power failure.
Outdoor Fan
Fuse blown or circuit breaker tripped.
Will Not Start.
Defective thermostat, contactor, transformer,
control relay, or capacitor.
Insufficient line voltage.
Incorrect or faulty wiring.
Thermostat setting too high.
High pressure switch tripped.
Low pressure switch tripped.
Freeze-up protection thermostat tripped.
Compressor Will Not Faulty wiring or loose connections in
Start But Outdoor compressor circuit.
Fan Runs.
Compressor motor burned out, seized, or
internal overload open.
Defective run/start capacitor, overload, start
relay.
One leg of 3-phase power dead.
Compressor Cycles Refrigerant overcharge or undercharge.
(Other Than Normally
Defective compressor.
Satisfying
Insufficient line voltage.
Thermostat).
Blocked outdoor coil or dirty air filter.
Defective run/start capacitor, overload, or start
relay.
Defective thermostat.
Faulty outdoor-fan (cooling) or indoor-fan
(heating) 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.
Outdoor coil dirty or restricted.
Compressor Makes Compressor rotating in the wrong direction.
Excessive Noise.
(Sizes 005, 006 and
007 Only)
Excessive Head Dirty air filter.
Pressure.
Dirty outdoor coil.
Refrigerant overcharged.
Air in system.
Condensing air restricted or air short-cycling.
Head Pressure Low refrigerant charge.
Too Low.
Compressor valves leaking.
Restriction in liquid tube.
Compressor rotating in the wrong direction
(unit sizes 005, 006, 007)
Excessive Suction High heat load.
Pressure.
Compressor valves leaking.
Refrigerant overcharged.
Suction Pressure Dirty air filter (cooling) or dirty outdoor coil
Too Low. (heating).
Low refrigerant charge.
Metering device or low side restricted.
Insufficient indoor airflow (cooling mode).
Temperature too low in conditioned area.
Field-installed filter drier restricted.
Outdoor ambient below 25 F.
Table 33 — Heating and Cooling Troubleshooting
CAUSE
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.
See problem ''Excessive head pressure.''
Check system for leaks. Repair as necessary.
See problem ''Suction pressure too low.''
Check wiring and repair or replace.
Determine cause. Replace compressor.
Determine cause and replace.
Replace fuse or reset circuit breaker. Determine cause.
Recover refrigerant, evacuate system, and recharge to 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.
Recover refrigerant, evacuate system, and recharge.
Clean coil or remove restriction.
Reverse the 3-phase power leads as described in
Start-Up, page 42.
Replace filter.
Clean coil.
Recover excess refrigerant.
Recover refrigerant, evacuate system, and recharge.
Determine cause and correct.
Check for leaks; repair and recharge.
Replace compressor.
Remove restriction.
Reverse the 3-phase power leads as described in Start-Up, page 45.
Check for source and eliminate.
Replace compressor.
Recover excess refrigerant.
Replace filter.
Check for leaks; repair and recharge.
Remove source of restriction.
Increase air quantity. Check filter and replace if necessary.
Reset thermostat.
Replace.
Install low-ambient temperature kit.
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REMEDY