Troubleshooting: Cooling
PROBLEM | POSSIBLE CAUSE | TO CORRECT |
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| Low voltage. | Check for voltage at compressor. 115 volt and 230 |
| Thermostat not set cold enough or | volt units will operate at 10% voltage variance |
| Set thermostat to coldest position. Test thermostat | |
Compressor does not | inoperative. | and replace if inoperative. |
run. | Compressor hums but cuts off on | Hard start compressor. Direct test compressor. If |
| overload. | compressor starts, add starting components. |
| Open or shorted compressor | Check for continuity and resistance. |
| windings. |
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| Open overload. | Test overload protector and replace if inoperative. |
| Open capacitor. | Test capacitor and replace if inoperative. |
| Inoperative system switch. | Test for continuity in all positions. Replace if |
| Broken, loose or incorrect wiring. | inoperative. |
| Refer to appropriate wiring diagram to check wiring. | |
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| PROBLEM | POSSIBLE CAUSE | TO CORRECT |
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| Inoperative system switch. | Test switch and replace in inoperative. |
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| Broken, loose or incorrect wiring. | Refer to applicable wiring diagram. |
| Fan motor | Open Capacitor. | Test capacitor and replace if inoperative. |
| does not run. | Fan speed switch open. | Test switch and replace if inoperative. |
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| Inoperative fan motor. | Test fan motor and replace if inoperative. (Be |
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| sure internal overload has had time to reset.) |
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| PROBLEM | POSSIBLE CAUSE | TO CORRECT |
Does not cool, or cools
only slightly.
Undersized unit.
Thermostat open or inoperative.
Dirty filter.
Dirty or plugged condenser or evaporator coil.
Poor air circulation in area being cooled.
Fresh air or exhaust air door open on applicable models.
Low capacity – undercharge. Compressor not pumping properly.
Refer to Sizing Charts.
Set to coldest position. Test thermostat and replace if necessary.
Clean as recommended in Owner’s Manual. Use steam or detergents to clean.
Adjust discharge air louvers. Use high fan speed.
Close doors. Instruct customer on use of this feature.
Check for leak and make repair.
Check amperage draw against nameplate. If not conclusive, make pressure test.
PROBLEM |
| TO CORRECT | |
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| Fuse blown or circuit tripped. | Replace fuse, reset breaker. If repeats, check fuse |
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| or breaker size. Check for shorts in unit wiring and | |
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Unit does not run. |
| components. | |
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| Power cord not plugged in. | Plug in power cord |
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| System switch in "Off" position. | Set switch correctly. |
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| Inoperative system switch. | Test for continuity in each switch position. |
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| Loose or disconnected wiring at switch or | Check wiring and connections. Reconnect per wiring |
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| other components. | diagram. |
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