Table 36—Cooling Service Analysis
PROBLEM | CAUSE | REMEDY |
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Compressor and Condenser Fan | Power failure. | Call power company. |
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Will Not Start. |
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|
|
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Fuse blown or circuit breaker tripped. | Replace fuse or reset circuit breaker. |
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| Defective thermostat, contactor, transformer, or | Replace component. |
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| control relay. |
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|
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| Insufficient line voltage. | Determine cause and correct. |
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| Incorrect or faulty wiring. | Check wiring diagram and rewire correctly. |
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| Thermostat setting too high. | Lower thermostat setting below room temperature. |
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Compressor Will Not Start | Faulty wiring or loose connections in compres- | Check wiring and repair or replace. |
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But Condenser Fan Runs. | sor circuit. |
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|
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| Compressor motor burned out, seized, or in- | Determine cause. Replace compressor. |
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| ternal overload open. |
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|
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| Defective run/start capacitor, overload, start | Determine cause and replace. |
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| relay. |
|
|
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| One leg of | Replace fuse or reset circuit breaker. Determine |
| |
|
| cause. |
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Compressor Cycles (Other Than | Refrigerant overcharge or undercharge. | Recover refrigerant, evacuate system, and recharge |
| |
Normally Satisfying Thermostat). |
| to nameplate. |
|
|
| Defective compressor. | Replace and determine cause. |
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| Insufficient line voltage. | Determine cause and correct. |
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| Blocked condenser. | Determine cause and correct. |
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| Defective run/start capacitor, overload, or start | Determine cause and replace. |
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| relay. |
|
|
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| Defective thermostat. | Replace thermostat. |
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| Faulty | Replace. |
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| Restriction in refrigerant system. | Locate restriction and remove. |
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Compressor Operates Continuously. | Dirty air filter. | Replace filter. |
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| Unit undersized for load. | Decrease load or increase unit size. |
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| Thermostat set too low. | Reset thermostat. |
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| Low refrigerant charge. | Locate leak, repair, and recharge. |
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| Leaking valves in compressor. | Replace compressor. |
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| Air in system. | Recover refrigerant, evacuate system, and recharge. |
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| Condenser coil dirty or restricted. | Clean coil or remove restriction. |
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Excessive Head Pressure. | Dirty air filter. | Replace filter. |
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| Dirty condenser coil. | Clean coil. |
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| Refrigerant overcharged. | Recover excess refrigerant. |
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| Air in system. | Recover refrigerant, evacuate system, and recharge. |
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| Condenser air restricted or air | Determine cause and correct. |
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Head Pressure Too Low. | Low refrigerant charge. | Check for leaks, repair, and recharge. |
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| Compressor valves leaking. | Replace compressor. |
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| Restriction in liquid tube. | Remove restriction. |
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Excessive Suction Pressure. | High heat load. | Check for source and eliminate. |
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| Compressor valves leaking. | Replace compressor. |
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| Refrigerant overcharged. | Recover excess refrigerant. |
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Suction Pressure Too Low. | Dirty air filter. | Replace filter. |
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| Low refrigerant charge. | Check for leaks, repair, and recharge. |
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| Metering device or low side restricted. | Remove source of restriction. |
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| Insufficient evaporator airflow. | Increase air quantity. Check filter and replace if neces- |
| |
|
| sary. |
| |
| Temperature too low in conditioned area. | Reset thermostat. |
| |
| Outdoor ambient below 25 F. | Install |
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Evaporator Fan Will Not Shut Off. | Time off delay not finished. | Wait for |
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