User Guide

Local
Priority 1
Local
Priority 2
Network
Priority 1
Network
Priority 2
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 (or Boiler Max) to turn
the boiler ON.
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BOILER OFF DIFF
s This is the amount the temperature must rise above target (or Boiler Max) to turn the
boiler OFF.
xx
MAX ON TIME
s Maximum time boiler will run on this priority if it is being asked to run on another
priority. Will rotate among all priorities its being asked to run. Network boilers are also
controlled by NET MAX ON TIME (see Figure 24, page 48).
s NETWORK PRIORITY 1 only — Maximum time master will operate the network on
NETWORK PRIORITY 1 if NETWORK PRIORITY 2 is calling for heat.
s
When the master boiler detects a local call for heat from any boiler that is
currently operating for a network demand, the master control will allow that boiler
to switch to its local priority and replace the lost network energy of that boiler ap-
propriately.
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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.
Network boilers are also controlled by NET MIN ON TIME (see Figure 24, page 48).
s NETWORK PRIORITY 2 only — Minimum time master will operate on a network
priority 2 if network priority 1 is calling for heat.
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RUN BOILER PUMP
s Selects whether the Boiler Pump is turned on while running on this priority.
xxxx
RUN AUX PUMP/
OUTPUT
s When set to YES, input/output pairs on any network boiler assigned as AUX PUMP/
OUPUT -> ANY TT INPUT BY ITS PRIORITY, will activate. Set this to NO for priori-
ties 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.
xxxx
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.
x
x
MAX SYS MBH
s Limits the energy allowed by the boiler network to be put into this priority’s system.
The default is set to AUTO (the sum of all network boiler sizes). If the total size of the
boiler network is too large for a system, adjust MAX SYS MBH lower to the appropriate
energy. MAX SYS MBH can be set greater than AUTO if more Evergreen
®
boiler are
planned to be installed to the same network. This setting can be adjusted in 100 MBH
increments (100 MBH = 100,000 BTU/hours).
x
x
MIN BOILERS
s The Master turns on this many boilers in the network on an initial call for heat in order to
avoid delays due to accumulative wait times between boilers. When switching to another
network priority, MIN BOILERS is re-evaluated based on the other priority’s setting.
xx
MAX RATE
s Maximum rate this boiler will modulate up to while running on this priority.
xx
MIN RATE
s Minimum rate this boiler will modulate down to while running on this priority.
xxxx
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
RESPONSE TIME timer. If the call for heat is still active when the RESPONSE TIME
expires, the boiler will close its additional heat demand contact.
s Timers reset when priorities are switched.
s NETWORK PRIORITY 1 or 2 — The additional heat demand must be wired to the
master boiler.
s LOCAL PRIORITY 1 or 2 — The additional heat demand must be wired to the indi-
vidual boiler. A master boiler cannot use additional heat demand on a local priority.
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RESPONSE TIME
s Time to wait for system to respond before taking the Activate Contact action. If ACTI-
VATE CONTACT is OFF, this line does not appear.
Figure 28 Evergreen
®
PRIORITY menus, continued
Part number 550-100-193/0817
– 53 –
®
CONDENSING GAS BOILER — 70/110/155 Advanced Manual
Network Boiler PRIORITY menus (continued)