This product is part of the NEMA Pressure Switches range, an offer of mechanical alternators. Mechanical alternator provides a simple, positive means of mechanically alternating two pumps or motors. This alternator is used on devices that are installed in a duplex system with a common tank. This mechanical alternator is a customer special. The open tank mechanical alternator supports flange mounting method. It is furnished with screw clamp terminals for electrical connection. It is a NEMA 1 rated product. Mechanical alternator provides a simple, positive means of mechanically alternating two pumps or motors. This alternator is used on devices that are installed in a duplex system with a common tank. A complete line of switches designed for open or closed tank applications they detect rising or falling liquid levels in various types of containers. The Square D brand water pressure switch has expanded to industry leading Pressure Sensors and Switches.