Direct start refers to the simple switching on of an electric motor that is connected directly to the mains.
Due to the fixed mains frequency, excessive currents of up to twenty times the rated current occur during start-up. In addition, the initial torque is very high, which leads to pressure surges in the system, e.g. with pump controls.
For this reason, depending on the supply area, there is a maximum permissible motor size that can be started directly.
An extension of the direct start is the so-called star-delta start-up.