There are two reasons why a single-phase motor does not start after being energized. On the one hand, there are mechanical reasons for the motor, and on the other hand, there are reasons for the electrical aspects of the motor.

For mechanical reasons, you can roll the shaft of the motor by hand to see if the motor can roll flexibly. At the same time, you can also use a screwdriver to put the screwdriver on the front and rear covers of the maintenance method of the single-phase motor that does not start after power-on. Listen to the motor inside. After there is no scavenging friction sound and the bearings are short of lubricating oil or worn, some abnormal noises are issued.

After judging that the mechanical aspects are normal, it is necessary to check the circuit. Disconnect the power cord from the switch, open the junction box on the motor, and use the buzzer gear of the multimeter to check whether the single-phase motor does not start after power-on to check whether the power cord is open-circuited. , you need to replace the power cord or find the breakpoint and reconnect it, and then wrap the insulating tape to deal with it. If the power cord is normal, you must check the two capacitors. The first thing to check the capacitor is to see if the capacity of the capacitor has a single-phase motor. The maintenance method that does not start after power-on or whether the capacity is reduced.

If both capacitors are also normal, then you need to check the main winding, secondary winding, and centrifugal switch inside the motor. Find the two terminals U1 and U2 of the main winding on the wiring seat of the motor, and use the multimeter to measure the resistance of the main winding in the small Ω range. The value is generally in the range of several Ω - hundreds of Ω, which is mainly related to the power of the motor. The smaller the motor power, the greater the measured resistance value. On the contrary, it is small.

After judging the main winding, no problem is found, continue to check the secondary winding, and find the maintenance method of the two single-phase motors connected to the secondary winding on the terminal block that do not start after power-on. The resistance value is normally a little larger than the resistance value of the main winding, if the secondary winding is also normal. The next thing to check is the centrifugal switch. The faults of the centrifugal switch are broken wires, non-closed contacts or poor contact. These are the maintenance methods for the multimeter's bee single-phase motor that does not start after it is energized. Check the two wirings of the centrifugal switch. Terminals V1 and V2 are easy to check. The trouble is that the contacts of the centrifugal switch are ablated and stuck together. This kind of fault is not easy to identify with a multimeter, and it is necessary to open the rear end cover of the motor to find it.