Armstrong World Industries 182, 243, 302, 242, 122, 123, 203, 183 manual Troubleshooting

Service Reference Manual TROUBLESHOOTING

9-5

overload protector has opened. Before the compressor can be con- demned as having a burned out start or run winding, it must be deter- mined that the overload switch is in fact closed. It may take several hours for the compressor to cool down enough to guarantee that the switch has closed. After enough time has elapsed for the switch to close, the resis- tance between each of the terminals should be measured. It may be found that with the overload switch closed, the compressor checks out electrically sound. If this is the case, then other possibilities have to be looked at as to what caused the compressor to overheat.*

There are several reasons why a compressor would overheat.

•If the capacitor was incorrect or failing, the amp draw (current flow) would be increased. This could cause the motor to heat up very rapidly, activating the thermal overload protection device. This would interrupt power and protect the motor windings from damage.

•A loss of charge could also cause the operating temperature of the compressor to rise and open the thermal overload switch.

•Restricted airflow through the coil could also cause the operating temperature of the unit to rise.

It is important to perform these checks before making a decision as to the condition of the compressor.

*An open thermal overload device in a motor does not mean that the motor was damaged or harmed in any way.

SRM-HW/HWC 8/99