User Guide

Figure 28 Evergreen
®
Network Boiler PRIORITY menus (access menus from CONTRACTOR menu
Local
Priority 1
Local
Priority 2
Network
Priority 1
Network
Priority 2
MENU ITEM DESCRIPTION
xx
INPUTS ASSIGNED
s List of inputs assigned to this priority/system on the local boiler (appears as 1, 2, 3).
xxxx
SYSTEM TYPE
s Select the system type for this PRIORITY, based on the heating terminal units in the
system. Use the CUSTOM selection to set the control for a different system type. The
factory preset values for SUPPLY MAX, SUPPLY MIN, OD RESET MAX and OD RESET
MIN are chosen based on the normal best setting for the terminal units. See page 45.
xx
TARGET MOD
SENSOR
s Read only — shows whether boiler modulates based on System Supply sensor (network
priority) or Boiler Outlet sensor (local priority).
xxxx
TARGET ADJUST
s Select how target temperature is calculated by control: NONE (no reset, fixed target
temperature), 0–10V (target temperature based on analog input from remote source),
ODT (outdoor reset operation).
xxxx
SUPPLY MAX
s Set SUPPLY MAX to the required supply water temperature for the system at design
maximum heat loss (typically 180°F for finned tube baseboard on new installations.)
xxxx
SUPPLY MIN
s SUPPLY MIN should equal the desired minimum supply water temperature for the
system. This line will not show if Target Adjust is selected as NONE.
xxxx
OD RESET MAX
s Appears if TARGET ADJUST is set to ODT. Outdoor temperature at which the target
temperature reaches its minimum value – usually set at the balance point temperature
for the building. (Does not appear if 0–10V or NONE is selected for Target Adjust.)
xxxx
OD RESET MIN
s Appears if TARGET ADJUST is set to ODT. Outdoor temperature at which the target
temperature reaches its maximum value – usually set at the outdoor design temperature
for the installation. (Does not appear if 0–10V or NONE is selected for Target Adjust.)
xxxx
VOLTS FOR MAX
s Appears if 0–10V is selected for Target Adjust. Set the voltage at which SUPPLY MAX
temperature is required.
xxxx
VOLTS FOR MIN
s Appears if 0–10V is selected for Target Adjust. Set the voltage at which SUPPLY MIN
temperature is required. For voltages between Min and Max, the target temperature
will be adjusted on a linear curve.
xxxx
BOOST TIME
s Every time the call for heat surpasses this duration of time the target temp will increase
(boost) up 10°F to a maximum temperature of SUPPLY MAX.
xx
SYSTEM OFF DIFF
s This is the amount the temperature must rise above system target to turn the boiler(s)
OFF.
xx
SYSTEM ON DIFF
s This is the amount the temperature must drop below system target to begin network
modulation routine. (This line may NOT appear, depending on TARGET ADJUST
setting.)
xx
ADD BLR DIFF
s If the system supply temperature has not reached target minus this differential at the
end of the STABILIZE TIME, the control will turn on the next available boiler in the
boiler firing order.
xx
DROP BLR DIFF
s If the system supply temperature rises to more than target plus this differential, the
control will turn off the last firing boiler in the boiler firing order. Drop Delay Timer
limits how quickly multiple boilers drop off.
xx
MOD DELAY TIME
s The time allowed for the boilers to adjust to the requested firing rate before beginning
Stabilize Time and resuming modulation.
xx
STABILIZE TIME
s The time allowed for all boilers actively heating a network priority to reach target modula-
tion rate requested by the master. If the timer expires and system temperature is less than
target – ADD BLR DIFF, the master will add the next available boiler. If there are no more
available boilers, the master will freely modulate the boilers to satisfy the heat demand.
xx
ADD DELAY TIMER
s Timer starts when the modulation rate of all boilers actively heating a network priority
are at BASE RATE HIGH, MAX RATE FOR NET, or are being self-limited. If the timer
expires and system temperature is less than target – ADD BLR DIFF, the master will add
the next available boiler.
x
x
DROP DELAY TIMER
s Minimum time before a boiler will be dropped off. This timer only begins after the first
boiler has been dropped. It applies as each additional firing boiler is dropped.
®
CONDENSING GAS BOILER — 70/110/155 Advanced Manual
Part number 550-100-193/0817
– 52 –
Network Boiler PRIORITY menus
Boiler Model, Altitude and Fuel Type are criti-
cal settings.
Failure to set correctly could result in
severe personal injury, death or substantial property
damage.
1. Access contractor menus by pressing and holding the UP and
DOWN arrow keys at the same time for 7 seconds.
2. See Figure 22, page 46 for the screen sequences up to the
CONTRACTOR menu.