The McDonnell & Miller 150S-HD Low Water Cut-Off—USNP variant—is a pump-control safety device that automatically shuts off a pump when water falls below a preset level, helping prevent dry-running and potential equipment damage. Identified as model 150S-HD (also listed as 150SHD) within Xylem's McDonnell & Miller line, this unit is designed for pump-control applications where reliable water-level monitoring is critical. In operation, it functions as the protection component that triggers a cut-off when water level is too low, safeguarding the system and upstream equipment.
