Advanced User Guide

Part number 550-100-160/0715
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Priority 1 Priority 2 Priority 3
MENU ITEM DESCRIPTION
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MAX BLR TEMP
s If the boiler outlet temperature approaches [MAX BOILER TEMP – BOILER ON DIFF] before
the system supply temperature reaches its target, the control will modulate the boiler based on
the boiler outlet temperature. The boiler will cycle and modulate based on the boiler ON and
OFF differential settings. (This line does NOT appear if Target Mod Sensor is set to Boiler Out).
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BOILER ON DIFF
s This is the amount the temperature must drop below target to turn the boiler ON.
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BOILER OFF DIFF
s This is the amount the temperature must rise above target to turn the boiler OFF.
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MAX ON TIME
s Maximum time this boiler will run on this priority if it is being asked to run on another prior-
ity. Will rotate among all priorities its being asked to run.
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MIN ON TIME
s Minimum time the boiler will run on an existing priority before switching to a lower priority,
or back to an existing higher priority. If a new higher priority is called during MIN ON TIME,
the boiler will immediately switch to actively heat the higher priority.
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RUN BOILER PUMP
s Selects whether the Boiler Pump is turned on while running on this call for heat.
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RUN AUX PUMP/
OUTPUT
s When set to YES, any input/output pairs assigned as AUX PUMP/OUPUT -> ANY TT INPUT
BY ITS PRIORITY, will activate. Set this to NO for priorities that do not need this AUX PUMP/
OUTPUT to be active.
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PRE PUMP
s Time associated PUMPS and AUX PUMP/OUTPUT are run before entering prepurge.
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POST PUMP
s Time associated PUMPS and AUX PUMP/OUTPUT are run after the call for heat has ended
and before switching to another call for heat.
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MAX RATE
s Maximum rate this boiler will modulate up to while running on this priority.
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MIN RATE
s Minimum rate this boiler will modulate down to while running on this priority.
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ADD’L HEAT
DEMAND
ACTIVATE CONTACT
s If this is set to 1st: Immediately on a call for heat, the heat demand contacts close and the
RESPONSE TIME timer starts. If the call for heat from this demand is still active at the end
of the Response Time and the system has not reached [Target Temp – System On Diff], the
boiler system will start. If the system temperature is within this range, the boiler system will
not start unless the temperature drops below this value. The add'l heat demand contact opens
when the heat demand turns off.
s If this is set to 2nd: The boiler system starts immediately on a call for heat and starts the RE-
SPONSE TIME timer. If the call for heat is still active when the RESPONSE TIME expires, the
boiler will close its additional heat demand contact.
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RESPONSE TIME
s Time to wait for system to respond before taking the Activate Contact action. If ACTIVATE
CONTACT is OFF, this line does not appear.
Figure 28 Evergreen single boiler PRIORITY menus, continued
CONDENSING GAS BOILER — Advanced Manual
™
Single Boiler PRIORITY menus (continued)