Three-phase Asynchronous Motor Starting Modes

1, direct starting. Three-phase asynchronous motor direct starting current up to 6-7 times the rated current, large impact on the grid, especially high power motors.

2, reduced voltage starting. Reduced voltage starting main thermal coupling voltage starting and star-Delta reduced voltage starting.

Hot Lotus root reduced voltage starting by means of autotransformer starting motor voltage and reduce starting current. 55%-75% the general reduction of the rated voltage. Advantage is that by changing the autotransformer tap number to easily change the starting voltage. Disadvantage is the need to use autotransformer, is costly.