Three=phase electric motor reversing circuit - employs two pole switch for each winding, for short circuiting during changeover

摘要

The reversing circuit for a three phase electric motor operates so that after disconnecting the motor windings from the power supply connections corresponding to one direction of rotation and before connecting them for the other direction, at least one section of the motor windings is short circuited. Each section of the windings incorporates a switch or a switch contact forming part of a bridging over current path. When the winding section is short circuited, a two pole protective switch can be used. The combined switching arrangement can be formed as a three pole switch. The switching sequence can be carried out in an overlapping manner, and the closing angle can be adjusted. Main and auxiliary windings can be short circuited by a capacitor.