Phase Inverter Plug The Phase inverter plug represents a novel solution for the problem of 3-phase rotating equipment turning in the wrong direction. Two of the phase contact pins are mounted on an insulated plate which can be rotated, but which is held by a pressure interlock when inserted into a socket. If the motor rotates in the wrong direction, then the interlock is simply depressed with a screwdriver and the insulated plate is rotated. This takes only seconds and the motor then turns in the correct direction. The switching of wires between terminals, which is time consuming and dangerous for untrained personnel, is no longer necessary.