This product is part of the NEMA Pressure Switches range, an offer of mechanical alternators. This mechanical alternator has 4 normally closed, snap action, DPST-DB (double pole single throw, double break) form YY contacts. The open tank mechanical alternator supports pedestal mounting method and vertical float rod angle for operating in any position. It is furnished with screw clamp terminals for electrical connection and 4 knockouts for 1/2inch or 3/4inch conduit. Offers electrical durability of 100 cycles and mechanical durability of 300 cycles. The enclosure is made of painted cold-rolled steel. It is a NEMA 1 rated product. This product is certified by UL, CSA, CE. Meets UL 508 standards. When liquid level rises to the first level, one pump turns on. Both pumps automatically turn on when a peak condition occurs and the liquid level continues to rise. If form N5 or N25 is present and the water level continues to rise. 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 product is certified by CSA and UL. It meets CE and UL 508 standards. 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.