ALLCS500MA45-21 Stainless Steel Float Liquid Level Control Switch (0.5A, NO/NC)

The ALLCS500MA45-21 is a compact stainless steel float-type liquid level control switch for sensing liquid levels in water containers, ponds, fish tanks and similar vessels. A shallow stainless float rises and falls with the liquid; at a pre-set level it actuates an internal reed relay contact, switching from closed to open or open to closed.

The switching direction is reversible by reversing the float mounting orientation, so the switch can be configured either normally open or normally closed. It features all-stainless-steel construction with corrosion-resistant SUS304/SUS316 parts, high sensitivity, high temperature resistance, oxidation resistance and moisture protection, with a rated life of 10⁷ operations at resistive load.

It is used in household appliances (water dispensers, humidifiers, dehumidifiers, water heaters, air conditioning, drinking water systems), industrial equipment (coolers, drainage, lubricating oil systems), gardening, medical and salon equipment, aquaculture, water purification, and sewage treatment. Installation requires a 10 mm hole in the container; the liquid must have a specific gravity greater than 0.75. The factory-set action point cannot be adjusted, but a custom trigger level is available on request.