Electrical fault of three-phase asynchronous motor

1. Single phase fault
This situation occurs when any phase of the power supply voltage is lost. This is because the normal operation of a three-phase induction motor requires a three-phase voltage source. Due to this malfunction, the motor may burn out or generate heat.

2. Reverse phase sequence fault
When any phase of the three-phase power supply is reversed, that is, when the phase sequence of the power supply voltage is exchanged, a reverse sequence fault will occur. Due to this malfunction, the direction of rotation of the motor has changed.

3. Fault of low and high power supply voltage
This fault occurs when the power supply voltage is below or above a specific limit. The voltage limit for three-phase AC power supply is 380 to 440 volts, so when the power supply voltage exceeds this limit, the motor may burn out or heat up.

4. Overload fault
When the output terminal of the motor is connected to a high load, overload occurs, and due to this load, the motor may generate heat or experience excessive vibration.

5. Grounding fault
This fault occurs when any phase of the power supply voltage is connected to the motor casing. Therefore, this will result in a complete short circuit of the motor. In this case, if someone touches this motor, they will feel severe vibrations. In addition, the motor will take over the current, which may be dangerous for induction motors.

6. Interturn short circuit fault
This type of fault occurs when two turns of the same or different phases are short circuited to each other. During this malfunction, the motor may suffer complete damage or damage to the coils of specific phases.

7. Crawling malfunction
This is basically an electromechanical fault of the three-phase induction motor. This fault occurs when the motor is fully loaded with power supply voltage. It does accelerate, but its operating speed is almost one seventh of synchronous speed. The special phenomenon of induction motors is crawling.