This Water Source pressure switch is designed for use with submersible well pumps or jet pumps, and must be used in conjunction with a well pressure tank. It signals the pump to start when the system's pressure drops below a certain PSI, and it stops once it reaches the maximum PSI. The PSI range is factory set, and it can be wired to 115 volt or 230 volt systems. | Water Source 20/40 Well System Pressure Switch