Abstract: A three-phase A.C. motor is connected to a three-phase A.C. supply through three sets of oppositely poled SCR's, one set being connected in each phase. Triggering pulses are supplied to the gates of the SCR's by triggering circuits. During starting of the motor, triggering circuits control the phases of the triggering pulses in relation to the phases of the supply in accordance with a ramp signal developed by the solid state starter circuit. The ramp signal increases the conduction angles of the SCR's until the motor has accelerated to running speed at which time maximum conduction of the SCR's is attained. The solid state starter circuit features closed loop control in generating the ramp. An overload protector circuit establishes different overload levels during starting and running of the motor and operates to terminate the application of triggering pulses to the SCR's if a motor overload condition is sensed during either starting or running.