4-38. REFRIGERATOR/FREEZER - MAINTENANCE INSTRUCTIONS (Continued).
Before replacing overload protector, disconnect the power
supply to the unit. Remove leads from terminals, remove
protector, install new (like) protector and reconnect leads.
The overload protector, and the starting relay, are attached to a
bracket which is welded to the compressor shell, with a metal cover.
The motor overload protector is a small round plastic casing which has
a bi-metallic metal strip (A) and a heater coil (B) inside. The heater coil
is made to carry normal start and run current. If the current increases
abnormally for any reason, then the heater coil gives off excessive
heat, which in turn, causes the bi-metallic disc to snap open, which
breaks the electrical circuit and the motor stops. Also, if the
compressor shell gets too hot, the bi-metallic disc snaps open,
breaking the circuit, stopping the motor and protecting the motor from
excessive heat and/or current. When the temperature cools down, the
bi-metallic disc snaps closed, and starts the motor. If the motor
overload protector fails to operate properly, it must be replaced.