COMPONENT OPERATION AND TESTING
WARNING
DISCONNECT ELECTRICAL POWER TO THE
UNIT BEFORE SERVICING OR TESTING
COMPRESSORS
Compressors are single phase, 208/230 volt. All compressor motors are permanent split capacitor type, using only a running capacitor across the start and run terminal.
All compressors are internally spring mounted and externally mounted on rubber isolators.
Line Voltage Overload
The compressor is equipped with an internal line voltage overload. This overload is embedded in the windings of the motor to sense the motor temperature. The overload will open and disconnect the power to the motor due to high temperatures caused by:
1.A locked rotor.
2.Excessive running amps.
3.High discharge temperature.
4.Low refrigerant charge.
FIGURE 1 INTERNAL OVERLOAD
LINE BREAK
INTERNAL OVERLOAD
OHMMETER
COMPRESSOR WINDING TEST (Figure 2.)
Remove the compressor terminal box cover and disconnect the wires from the terminals. Using an ohmmeter, check continuity across the following:
FIGURE 2 COMPRESSOR WINDING TEST
Testing Procedures
1.Terminal "C" and "S" - no continuity - open winding - replace compressor.
2.Terminal "C" and "R" - no continuity - open winding - replace compressor.
3.Terminal "R" and "S" - no continuity open winding - replace compressor.
4.Terminal "C" and the shell of the compressor
– continuity – grounded motor – replace compressor.
5.Should continuity exist between terminals "R" and "S", but not between terminals "C" and "S" and "C" and "R", the internal overload may be open. If the compressor is extremely hot, allow it sufficient time to cool. It may require as long as one hour for the compressor to cool sufficiently for the internal overload to close.
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