The standard switch includes a power train and motor housing assembly. However, the switches can be supplied in a "Manual Only" configuration (without the motor housing assembly).
The oil switch can be operated electrically or by the manual lever. In the automatic mode, the electric motor output torque, amplified by a steel-to-steel gear train, rotates a double cam to throw the moving contact assembly and actuate the microswitch to prepare for the next half cycle demand signal. The neutral lead from the motor and the tank should be properly grounded for safety and to prevent damage from transient voltage surges.