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PROBLEM POSSIBLE SOLUTION
Compressor starts and runs, but cycles on overload 1.- Low voltage.
2.- Running capacitor defective.
3.- Overload protector defective.
4.- High head pressure.
5.- Fan motor, pump, etc… , wire to wrong of overload protector.
Compressor tries to start when thermostat closes but
cuts out on overload, start after several attempts.
1.- Low voltage.
2.- Start capacitor defective.
3.- Overload protector defective.
4.- High head pressure.
5.- Fan motor, pump, etc… , wire to wrong of overload protector.
Compressor tries to start when thermostat closes but
cuts out on overload, start after several attempts.
1.- Low voltage.
2.- Low on oil.
3.- High head pressure.
4.- Starting relay points badly pitted.
5.- Starting capacitor weak.
6.- Air or non-condensable gases in system.
Compressor starts but immediately cuts out on overload 1.- Starting relay contacts points welded together.
2.- Starting capacitor defective.
3.- Compressor short cycles.
Starting relay burns out. 1.- Low voltage.
2.- High voltage.
3.- Compressors short cycles.
4.- Incorrect running capacitor.
5.- Incorrect relay.
Running capacitors burn out. 1.- Line voltage too high.
Head pressure to low 1.- Insufficient refrigerant charge.
2.- Leak in the system.
3.- Cold location.
Head pressure to high 1.- Unit overcharged.
2.- Air or other non-condensable gases in system.
3.- Clogged condenser (air-cooled)
4.- Defective condenser fan motor.
5.- Unit location too hot.
6.- Restriction in expansion valve, strainer or drier.
7.- Discharge valve partially closed.
8.- Restriction in discharge line.
Compressor short cycles 1.- Control differential set too close.
2.- Refrigerant undercharge, check pressure control.
3.- Refrigerant overcharge.
4.- Discharge valve leaking.
5.- Cutting out on high pressure control, if used.
6.- Cutting out on overload protector because if tight bearings struck piston, high
head pressure or restricted air cooled condenser.
Running cycles too long, or unit operates continuously 1.- Insufficient refrigerant charge.
2.- Dirty or restricted condenser.
3.- Unit location too hot.
4.- Control contacts stuck.
5.- Air or other non-condensable gases in system.
6.- Expansion valve plugged or defective.
7.- Fixture doors left open too long.
8.- Insufficient, defective or water logged insulation.
9.- Evaporated oil logged.
Noisy unit 1.- Compressor oil charge low.
2.- Fan cable on condenser or evaporator bent causing
vibrations.
3.- Bearing on evaporator or condenser motors lose or worn.
4.- Tube rattles.
5.- Lose parts on condensing unit.
6.- Case is not level.