Jiangmen reducer: what kind of problems will happen if the motor wiring is wrong?

2020-07-06 125

Asynchronous motor is the most widely used motor at present. The wiring method of its motor winding is divided into star connection y and triangle connection Δ. The following Jiangmen speed reduction motor will introduce the result of wrong wiring.

For a motor with star shaped stator winding, the voltage accepted by each phase winding, i.e. phase voltage, is 1 / 3 times (0.58 times) of the additional voltage (power line voltage) of the motor. In case of wrong connection and triangle operation, the phase voltage will increase to 1.73 times of the manufacturer's regulation. For example, if the power supply voltage is 380 V, the star operation, the phase voltage is 220 V, and if connected in a triangle, the phase voltage will rise to 380 v. Because the phase voltage of the winding increases, the iron core will be highly saturated, and the excitation current of the iron core flux will increase rapidly. In addition, with the load current, the current of the stator winding will increase greatly, which will lead to the sharp increase of the copper loss of the winding and lead to the overheating and burning of the stator winding.


2. For the motor with triangular stator winding, the phase voltage accepted by each phase winding is the additional voltage (power supply voltage) of the motor. If the wrong connection is star shaped, the voltage on each phase winding will drop to the primary power For example, if the power supply voltage is 380 V, the phase voltage will drop to 0.58 * 380 = 220 V, resulting in the torque of the motor will be reduced to (1 / 3) 2 = 1 / 3 of the additional torque. At this moment, if the motor is still In order to overcome the resistance torque of the load, the torque of the star connection method is the same as that of the triangle connection method. In this way, the stator current of the motor will increase, which will lead to overload and heating of the motor. The long-term operation will also burn down, and the power factor and power will also drop.

3. There is also a special case, if the load of the motor is light (less than 40% of the additional load), the large load current is not required to generate electromagnetic torque to overcome the resistance moment. At this moment, the stator winding is controlled by Because the phase voltage of winding is greatly reduced and the excitation current is obviously reduced, the total stator current is also reduced, and the power factor and power of the motor are correspondingly increased. When a large horse pulls a small car, that is, when the load of the motor is less than 40% of the additional load, the motor is artificially changed from triangle to star to achieve the purpose of energy saving and consumption reduction.

Source: Jiangmen reducer http://www.fenghengjidian.com