CALEFFI Z-one ZSR10X Series - Page 19

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Sequence of Operation / Settings
• A demand occurs from one of the thermostats
which sends power (from a separately sourced
transformer) to the corresponding zone valve.
• When the zone valve opens the end switch
will close R to W on the ZSR101 control. The
“ZONE”LEDilluminates.
• The ZSR101 control will power relay #1 and
#2 closing C to NO.
• The NO terminal of relay #1 will send out
120 VAC to your pump. Relay #2 provides
a dry contact closure to signal the boiler of a
demand.
• NOTE: Relay #1 can be used as a dry contact
as well by removing the factory installed
jumper between L and C.
• When all the thermostat demands are satisfied
the zone valves will close and the end switch
willopenRtoW. The“ZONE”LEDwillturn
off.
• The control will remove power from relays #1
and #2 opening C to NO. This will drop 120
VAC to your pump and terminate the demand
to your boiler.
WARNING: NEVER CONNECT R & C DIRECTLY,
this will be a direct short on the 24 VAC supply
Description of terminals
= Ground
N = Neutral (Common leg of 120 VAC)
L = Line (live leg of 120 VAC)
C = Common terminal
NO = Normally Open terminal
NC = Normally Closed terminal
Note: There is a factory installed jumper between the 120
VAC line (L) and the common terminal of relay #1 (C).
Thermostat terminals
R = 24 VAC
W = Heat call
C = Common of 24 VAC