Internal structure of ordinary compressor motor. The motor running winding CR and the starting winding CS inside receive 220V AC voltage. With the cooperation of an external starting capacitor, magnetic fields of different phases flow through the main winding and the starting winding, thereby generating a rotating magnetic field, which causes the motor rotor to rotate and drive compression. The machine works. On the one hand, it forcibly inhales the gas through the suction port and compresses it in the cylinder, so that the gas volume becomes smaller, and the density of gas molecules in the unit volume increases to increase the air pressure. At the same time, the temperature of the gas during the compression process is caused by the friction between the molecules to make the temperature Lithium; gas compressed by the cylinder to high pressure and high temperature is discharged from the exhaust pipe, so that the gas is continuously transported from the low pressure, low temperature end to the high pressure, high temperature end. Therefore, the role of the compressor in the refrigeration system is like the human heart. The quality of the compressor directly affects the cooling (heating) effect of the air conditioner.

Some air conditioner compressors also have built-in overcurrent / overheat protectors (referred to as overload protectors, which are connected to the common terminal C of the compressor and are usually in the normally-on state. When the compressor's operating current is too high or the temperature is too high, the overload will occur. The protector automatically disconnects, cuts off the compressor winding power supply circuit, and forces the motor to stop. When the compressor operating current and temperature drop to a normal range, the overload protector automatically turns on the motor winding power supply circuit and the motor runs again.

Due to different compressor models and powers, some overload protectors are built-in and some are external; the overload protector disconnect temperature is also different. For example, the MRA12056-12016 compressor overload protector has an off temperature of (150 ± 5) ° C and an on temperature of (69 ± 9) ° C; the operating current (environment temperature is 25 ° C) is 6.3A, and the power is turned off for SOmindOO ^). On, or 14.8A is energized for 6s-16s (25 ° C). Another example is SHX33SC4 compression fl built-in overload protector, the disconnection temperature is 130 ℃, the switch-on temperature is 105 ℃, the operating current is 8.7A