Fisher & Paykel 635 Active Smart, Service Manual

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13.14.2 Compressor Won't Start - Hums
Possible Causes:
1. Voltage may be low e.g. 10% low. Test the voltage under load.
2. Check the voltage to the compressor from the power/control module.
3. System pressures may not be equalised; too short an off cycle.
4. Check the start and run windings with an ohmmeter.
13.14.3 Compressor Starts, Runs And Then Stops
Possible Causes:
1. Low voltage - high voltage.
2. Check the compressor voltage matches the supply voltage.
3. The system may be grossly overcharged, causing liquid refrigerant to enter the compressor low side
causing slugging of oil.
4. Check the current draw - overload protector.
5. The high pressure side may be fully or partially blocked. Very high head pressure. Normally a
blockage before the condenser.
6. The condenser too hot, e.g. air movement blocked or ambient temperature too high. The refrigerator
may be too close to a heating appliance.
7. Check the compressor pipe connections. The oil cooler may not be correctly connected. High head
pressure.
8. Check that the correct relay and / or overload is fitted and that it is operating correctly.
9. Overload - connect an amp meter, switch on and note the current draw. If the current normal as per
service specifications, and the overload activates, the overload must be defective or of the wrong type.
Short out the overload, and if the compressor runs normally, then the overload is faulty.
10. Test, with an ohmmeter, the compressor windings for continuity and correct resistance. Refer to the
compressor specifications.