The SZ2166 is a microprocessor based chiller controller. It is designed for use on multi-stage chiller applications and includes boiler support and control. • Stand-alone or network operation • Stand-alone or network operation • 365-day time clock with two holiday schedules, automatic leap year and daylight savings correction • No backup battery required for control parameters, schedule or clock • Hot water supply and return temperature inputs • Chilled water supply and return temperature input • Two digital outputs for chillers • One digital output for alarm • Mixed water temperature input • Outdoor air temperature input • Separate setpoint for thermal storage sequence • Outdoor air reset control • Two digital inputs for pump status • External time clock input • Six digital outputs for chillers, pumps and chiller stages • Adjustable offsets and differentials on digital outputs • Lead/Lag sequencing of up to six chillers • Two modulating analog outputs for valves and VFDs • Adjustable P+I+D control on modulating outputs • LEDs for monitoring status • Automatic rotation of pumps • Automatic rotation of chiller and boiler stages • Domestic hot water function • Local override and remote override capability |