JC35-6 Pressure differential Controls consists of two oppositely located bellows. One is H.P. Bellow and the other is an L.P. Bellow. The pressure differential actuating on two oppositely located bellows is balanced by a spring. If the pressure differential is less than the set point, owing to the lever action, the switch is on and keeps the electric heater in the time delay mechanism in operation. The contact of the time delay switch are then in off position after certain time delay interval (about 90 sec.) the power supply is cut off. A manual reset device is mounted in the time delay mechanism of the control. When the compressor has stopped due to oil pressure failure, the control cannot be reset automatically after it has actuated. Push the reset button after the error has been corrected. Then the time delay switch in the time delay mechanism will close the motor control circuit and start up the compressor.