The motor soft starter is a new type of starting equipment with the international advanced level designed and produced using power electronic technology, micro-processing technology and modern control theory.

The motor soft starter can effectively limit the starting current when the AC asynchronous motor starts. It can be widely used in loads such as fans, pumps, conveyors and compressors. It is a traditional star / delta conversion, self-coupling buck, magnetic control buck Ideal replacement product for pressure-reducing equipment.

Below, what are the advantages of using the motor soft starter?

1. Cause grid voltage fluctuations and affect the operation of other equipment in the same grid

When the AC motor starts directly at full voltage, the starting current will reach 4-7 times the rated current. When the capacity of the motor is relatively large, the starting current will cause a sharp drop in the grid voltage, affecting the normal operation of other equipment in the same grid.

When the motor uses a soft start cabinet, the starting current is generally 2 to 3 times the rated current, and the grid voltage fluctuation rate is generally within 10%, which has very little impact on other equipment.

2. Impact on the power grid

The impact on the power grid is mainly manifested in two aspects:

① The impact of the large current directly started by the super-large motor on the power grid is almost similar to the impact of the three-phase short circuit on the power grid, which often causes power oscillation and makes the power grid unstable.

②The starting current contains a lot of high-order harmonics, which will cause high-frequency resonance with the grid circuit parameters, causing malfunctions such as relay protection malfunction and automatic control failure.

When the motor is started with a soft start cabinet, the starting current is greatly reduced, and the above effects can be completely eliminated.

3. Injury to motor insulation and reduce motor life

① Joule heat generated by large current repeatedly acts on the outer insulation of the wire, which accelerates the aging of the insulation and reduces the life.

②The mechanical force generated by the large current causes the wires to rub against each other, reducing the insulation life.

③ When the high-voltage switch is closed, the jitter of the contact will produce an operating overvoltage on the stator winding of the motor, sometimes reaching more than 5 times the applied voltage. Such a high overvoltage will cause great damage to the motor insulation.