What is the reason why a three-phase asynchronous motor does not rotate?

1. Power supply not connected: If the power supply is not connected or has poor contact, it will cause the motor to not rotate. At this time, electricians should check the switch, fuse, various contacts, and wiring heads to gradually identify the fault and carry out maintenance;

2. When starting, the fuse of the fuse is blown, causing it to not turn: find out the cause of the melting, troubleshoot, and match the fuse with the same specifications according to the capacity of the motor;

3. The setting current of the overcurrent relay is too small, causing it to not turn: at this time, it should be adjusted to a higher level appropriately;

4. Excessive load or stuck transmission structure causing non rotation: choose a larger capacity motor or reduce the load, and check the condition of the transmission mechanism;

5. The stator or rotor winding is broken, causing it to not rotate: Open the junction box and use a multimeter ohm range to check if the motor winding is broken (wire breakage). If there is a broken circuit, there will be an abnormal resistance value. It is necessary to open the motor to further check the disconnection point and connect it properly;

6. Stator winding inter turn short circuit: The winding of an electric motor is composed of many turns of coils. When there is a short circuit between the coils, it may cause the motor to not rotate. You can use a multimeter to check and find the two compartments with the short circuit. Open the motor and disconnect the connecting wires of one phase of each coil. Group and check the short circuit point, and re insulate after finding it;

7. Stator winding short circuit to ground: Check with a megohmmeter or multimeter to find out the grounding winding. If the insulation is damaged, re insulate it. If it is severe, replace the winding; If it is damp, it can be dried and then coated with another layer of insulation paint;

8. Stator winding wiring error: Disassemble the motor to identify the error and rewire;

9. Poor contact of the rotor slip ring of the wound motor: Correct the slip ring indication and adjust the carbon brush pressure.