The staged Chilled Water Units are available in capacities ranging from 48,000 to 900,000 BTU/H. SCWs are available in single phase or three phase, 50Hz or 60Hz, and all standard voltages (208, 230, 380, 460 VAC). Multiple compressors and refrigerant circuits are incorporated to provide minimal power consumption versus load demands, as well as redundancy throughout the unit. Each refrigerant circuit is hermetically sealed and factory pre-charged with R-22. Each condensing unit is monitored and protected with freeze controls, high limit switches, high and low aquastats, timers and on-board fuses or breakers.