Refrigerator overheat protector knowledge


The overheat protector is also known as the overload protector, has overcurrent, overheating dual protection. When the refrigerator compressor is operating, the power supply voltage is too high or too low, the compressor temperature will rise very high due to the failure of the refrigeration system.


In order to protect the motor of the compressor without burning due to overcurrent or overheating, an overheater protector is set in the motor circuit.


1, double metal dish hot protector

This is the internal structure of a bimetal hot protector, which consists of a hot wire, a bimetal disc circon, and a contact switch. The bimetal hot protector has two working conditions. When the temperature of the thermal protector is normal, the bimetallic disc circular wafer maintains a normal state and the contact switch is normally closed. When the heat protector is overheating, the bimetal disc circon is generated and the contact switch is broken.

The bimetallic dish heat protector is mounted closely to the compressor housing. When the compressor is working fine, the temperature of the shell is normal, the bimetallic dish heat protector is turned on, and the motor is energized. When the compressor is overheating, the bimetallic dish heat protector is turned off, and the motor is powered off, stopped protection.

If the motor current is too large due to the compressor card or the like, the electric wire of the double metal disc system is highly warmed due to the large current, so that the bimetallic disc is quickly deformed, disconnected from the contact. Power supply, so that the motor avoids overcurrent and burns.

2, bury coil heat protector

The burying coil heat protector is embedded in the stator windings of the motor and is connected in series with the stator windings, which can both overheat protection, and can also overcurrent protection. This is the internal structure of the internal burying coil heat protector.

When the motor winding is too hot or current, the bimetallic sheet in the protector will be deformed, disconnected, and cut off the winding, so that the motor avoids high temperature or overflow.


The buffer protector is small, and the overheating protection is good, and the sealed insulating jacket prevents the infiltration of freezing oil and refrigerant.