CS pressure switches have a built-in pressure operated, three-pole switch. The contact position of which depends on the pressure in the connector and the range setting and adjustable differential. The pressure switches are fitted with a manual switch that will lock the contact system in the open position independently of the pressure in the system. Pressure switches with relief valve is used in compressed air systems where pressure relief on the compressor piston before start is required. The CS is suited for automatic start and stop of air compressors and water boosters