What happens when the motor is short-circuited?

Update:01 Feb 2019
Summary:

The short circuit between turns is that the same windin […]

The short circuit between turns is that the same winding is wound by many turns. If the insulation is not good, the coils that are stacked together will be short, which is equivalent to the fact that a part of the coil is directly short-circuited and does not work. After the short circuit between the turns, the winding of the motor is short-circuited due to a part of it, the magnetic field is different from the previous one, and the asymmetry is the same, and the remaining coil current is larger than before, and the motor will vibrate during operation.
Large, the current increases, and the output is relatively reduced.
The Taishuang motor has a short circuit between turns, which has the following phenomena:
1) A large circulating current will flow through the short-circuited coil (usually 2- to 10-fold of the normal current), causing the coil to heat up severely;
2) Three-phase current imbalance, motor torque is reduced;
3) Producing noise;
4) When the short circuit is severe, the motor cannot start with load. At the beginning of the turn-to-turn short circuit, only two wires may be in contact due to the insulation at the overlap. Due to the circulation in the short-circuit line, the coil is heated rapidly, further damaging the insulation of the adjacent wires, so that the number of turns of the short circuit is increasing and the fault is expanded. When the number of short-circuit turns is sufficient, the fuse will be blown, and even the winding will burn and smoke. When a phase of the three-phase winding has a turn-to-turn short circuit, the number of turns of the phase winding is reduced, and the three-phase current of the stator is unbalanced. Unbalanced three-phase currents cause the motor to vibrate while producing an abnormal sound. The average torque of the motor drops significantly, and it becomes weak when the load is dragged.

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