7.5KW motor hard start problem?

bigbat

7.5KW motor hard start problem? [Copy link]

Recently, a friend wants to install a water pump with a motor power of 7.5KW (three-phase power supply 380V). He does not want to buy a soft starter or a frequency converter, but a hard starter. Does the hard start of a motor of this power require a "star-delta" starter? Or, hard starter cannot be used.

qwqwqw2088

7.5KW is a small power motor, so it does not need frequency conversion and soft start. "Star-Delta" belongs to step-down start, which is commonly used for medium power motors. 7.5KW does not seem to need it.

maychang

"Star-delta" starting is a reduced voltage starting method. Reduced voltage starting means that the starting torque is reduced, but the current peak after closing is also reduced, and the impact on the power grid is relatively small.