There are two types of fan motors used for outdoor and indoor units of window air conditioners or split air conditioners: single end shaft extension and double end shaft extension. Single ended shaft extension single-phase asynchronous motors are mainly used in split type air conditioners, while double ended shaft extension single-phase asynchronous motors are mainly used in window type air conditioners. According to the different materials of the casing, asynchronous motors have two types: iron seal and plastic seal. The physical appearance of a typical single-phase asynchronous motor used in an air conditioner is shown in the following figure

The shell of an iron sealed motor is composed of two parts: the upper and lower parts, which are then fastened with screws. Its advantage is easy disassembly when repairing the motor, but its disadvantage is high noise. Due to the good heat dissipation effect of the iron shell with heat dissipation holes, the power of the iron sealed motor is relatively high. Therefore, air conditioners not only use iron sealed motors to drive axial fans inside outdoor units, but also use them to drive centrifugal fans of window type air conditioners and split cabinet units

Reminder: Due to the high power of iron sealed motors, in order to prevent motor overheating damage, it is generally necessary to set up an overheating protection circuit. Some thermal protection devices are installed inside the motor, while others are installed in the power supply circuit of the motor. Therefore, when replacing the motor, attention should be paid to whether the motor is equipped with built-in protective devices