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Sequence of Operation
Priority Jumper: ON (Zone #1 becomes priority)
Master/Slave Jumper: Master
Status During Priority: ON
•
A demand occurs from a T-stat (T-stat closes
TT terminals) in zones 2 thru 6. The “T-STAT
CALL” LED illuminates for that zone.
•
ZVR control sends 24 VAC to the corresponding
zone MOTOR terminals to open the zone
valve.
•
When the end switch on the zone valve closes,
the control sends 120 VAC to SEC PUMP and
SYSTEM PUMP. The “VALVE OPEN” LED
illuminates for that zone and the XX contacts
close to signal a heat demand to the boiler.
•
When the demand from the T-stat is satisfied
(T-stat opens TT terminals), both the “T-STAT
CALL” and “VALVE OPEN” LED’s turn off.
•
24 VAC is dropped from the corresponding
zone MOTOR terminals.
•
If no other zones are calling, power is dropped
to the SEC PUMP and SYSTEM PUMP and
the XX contacts are opened.
•
If a demand occurs from the DHW aquastat
(zone #1), The “T-STAT CALL” LED illuminates
for Zone #1 and the “VALVE OPEN” LED
will illuminate. (When using a DHW pump,
a jumper must be installed on Zone #1 end
switch terminals.)
•
If any other zone was calling (Zones 2 thru
6) when Zone #1 called, power (24 VAC) is
dropped to those zones.
•
The XX and DHW contacts close.
•
The PRIORITY PUMP and SYSTEM PUMP
contacts deliver 120 VAC
•
The SEC PUMP is off.
•
Once the Zone #1 DHW demand is satisfied,
power to the PRIORITY PUMP and SYSTEM
PUMP is dropped, the DHW contacts open.
•
If a demand from zones 2 thru 6 is present,
24 VAC is delivered to the corresponding
zone valve(s) and the “T-STAT CALL” LED’s
illuminate.
•
When the zone valve end switch closes,
the “VALVE OPEN” LED illuminates, the XX
contacts close, the SEC PUMP and SYSTEM
PUMP terminals deliver 120 VAC.
DHW Time Out \ Freeze Prevention Feature
•
After one hour of a priority demand, the control
will open the DHW contacts and turn off power
to the DHW pump and Zone Valve #1.
•
If a heating demand is present from Zones
#2- 6, the control will satisfy those demands
before going back to the DHW call.
•
After the heating demands are met, the control
will go back to DHW and re-set the one hour
timer.
Description of terminals
= Ground
N
= Neutral (common leg of 120 VAC)
L
= Line (live leg of 120 VAC)
Thermostat terminals
R = 24 VAC
W = Heat call
C = Common of 24 VAC
Boiler terminals
XX = Dry contacts rated up to 120 VAC, 2 Amps.
Closes when any zone calls including priority.
Typically connected to TT on boiler control.
DHW (ZR/ZC) = Dry contacts rated up to 120 VAC,
2 Amps. Closes only when priority is enabled and
calling. Typically used to close ZR\ZC (120 VAC)
or DHW contacts (24 VAC) on boiler controls
equipped with these features.
Pump terminals
SYSTEM PUMP = Runs when any zone calls for
heat. When priority is enabled, the status of the
pump (on\off) during a priority call is selected via
a jumper
SEC PUMP = Runs when any zone calls for heat
except the priority zone when it is enabled.
PRIORITY PUMP = Runs when the priority zone
calls. A jumper is required between the END
SWITCH terminals when using a pump.
Valve terminals
Motor = 24 VAC to power the zone valve motor
End Switch = Connects to end switch on zone
valve. Must be jumpered if using a 2 –wire zone
valve.
WARNING:
NEVER CONNECT R & C DIRECTLY,
this will be a direct short on the 24 VAC supply
