How to solve the problem of three-phase asynchronous motor not rotating without abnormal noise or odor?

This type of malfunction is mainly caused by the failure of the main circuit control equipment (frequency converter, contactor, soft starter, etc.) to operate. It can be checked whether the main circuit control equipment has received control commands in a timely manner, such as whether the main contactor is engaged, whether the frequency converter is powered on and in operation mode, etc.

If the main circuit control equipment is not functioning, then the status of the control circuit components should be checked:
1. Check if the power supply of the control circuit is normal by measuring the voltage value at the output terminal of the control switch. If it is not normal, check if the fuse is blown; Is the control switch turned on;

2. Whether the control circuit is connected. If it is a general relay control circuit, the voltage at both ends of the start button can be measured when it is powered on. When the control circuit is connected, the measured voltage should be the control circuit voltage, otherwise the measured voltage value will be lower than the control circuit voltage value.

It is possible to check whether the protective device is in operation, such as whether the thermal relay has not reset after being activated, whether the normally closed contacts of the relevant relays are connected, whether there are any broken wires, poor contacts, or burnt screws in the circuit, whether the relay and contactor coils are broken, and whether the intermediate relay contacts are burnt.

If the main circuit control equipment has been powered on, but the motor is not operating, it can be suspected that the main circuit circuit part:
1. The main circuit fuse has blown two phases;
2. The main contacts of the main circuit contactor are burnt out in two phases;
3. Motor phase failure;
4. The main circuit is disconnected.

These faults can be determined by measuring the resistance value in the event of a power outage.