472104011U03 Stearns SINPAC Electronic SwitchCV Series for 115 Vac or 115 230 Vac Dual Voltage Capacitor Start Motors Basic Operation Capacitor start motors require a method to extract speed data from the voltage across the motor start winding. By comparing the start winding RPM sensitive voltage with the main AC input voltage (which serves as a reference voltage), the switch determines when the start circuit should be energized. The electronic switch interrupts the start circuit current after