4 Zone Expandable Switching Relay Caleffi ZSR104

Multi-zone pump and boiler operating control for multiple zone hydronic heating systems.
Interfaces with low voltage thermostats or any other low voltage controllers having a switching action.

Controls from 3 to 6 heating circulator pumps (model dependent).
Primary pump with LED indicators to provide functional status and easy system troubleshooting.
Primary pump system circulator is switched on whenever any zone calls for heat.

Power supply:  120 VAC 50/60 Hz
Transformer voltage:  24 VAC
Max transformer load:
12 VA (ZSR103 and ZSR104)
20 VA (ZSR106)

Electrical switch rating:  20 A max combined
Electrical switch rating pump output:  120 VAC, 5 A each

Dry contact rating (AUX, XX, ZONE1 E/S):  120 VAC max, 2 A each

Replaceable fuses:  Type 2AG, 5 A slow blow