Common faults and causes of single-phase capacitor-started asynchronous motors

Common faults and causes of single-phase capacitor-started asynchronous motors

Single-phase motors are mainly divided into single-phase resistance starting, single-phase capacitor starting, single-phase capacitor operation, single-phase capacitor starting and operation, and single-phase shaded pole type according to different starting methods or operation modes. Capacitor starting and running asynchronous motors are the most common. In rural areas, due to poor power supply quality and improper use of the power grid, the failure rate of single-phase motors is relatively high, mainly manifested as serious motor heating, inability to rotate, difficulty in starting, and burning fuses. The common faults and causes of single-phase capacitor-started asynchronous motors are as follows:

Fault 1: The power supply is normal, and the motor cannot start after power-on. The reasons are: 1 motor lead wire open circuit; 2 main winding or secondary winding open circuit; 3 centrifugal switch contacts cannot be closed; 4 capacitor open circuit; 5 bearing stuck; & rotor and stator rubbing.

Fault 2: It can be started with no load, or can be started with external force, but the start is slow and the steering is uncertain. The reasons are: 1. The secondary winding is open; 2. The contact of the centrifugal switch is poor; 3. The starting capacitor is open or damaged.

Fault 3: After the motor starts, it heats up and even burns the windings. The reasons are: 1. The main winding is short-circuited or grounded between turns; 2. The main and auxiliary windings are short-circuited; 3. The centrifugal switch contacts cannot be disconnected after starting; 4. The main and auxiliary windings are connected to each other wrong;

Fault 4: The motor speed is low and the operation is weak. The reasons are: 1. The main winding is slightly short-circuited between turns; 2. The running capacitor is open or the capacity is reduced; 3. The bearing is too tight; 4. The power supply voltage is low.

Fault 5: Burn the fuse. The reasons are: 1. The winding is seriously short-circuited or grounded; 2. The lead wire is grounded or touched; 3. The capacitor is short-circuited by breakdown.

Fault 6: Too much noise when the motor is running. The reasons are: 1 winding leakage; 2 centrifugal switch damage; 3 bearing damage or too large gap; 4 foreign matter entering the motor.