Caleffi 6 Zone Expandable Switching Relay w/ Priority

Function The ZSR series is a zone pump and boiler operating control for multiple zone hydronic heating systems. The ZSR series interfaces with low voltage thermostats, or any other low voltage controllers having a switching action. The ZSR series controls up to 6 zone pumps (depending on model selected) and a primary pump. It has LED indicators to provide functional status and easy system troubleshooting. Features Compatible with 2, 3 and 4-wire thermostats or other low voltage controllers with switching action 120 VAC input Heavy duty, sealed, fuse protected relay (with spare fuse) 1 primary pump output and 3 to 6 (model dependent) zone pump outputs (120 VAC/5 A each) Zone priority selectable with 1-hour time-out feature Convenient R,W,C and T,T,COM dual labeling at thermostat terminals DHW (ZR/ZC) dry contacts rated for switching line voltage High capacity 12 VA or 20 VA transformer (model dependent) Automatic resettable fuse on 24 V circuit Selectable post purge Selectable pump exercising 3 pump ground ...