DEFAULT SETTINGS & MENU ITEM DESCRIPTIONS
HeatNet Control V3
Page 106
SPACE HEATING
DHW HEATING
TABS
If the MASTER TYPE is set to COMBINATION, or the DHW
BOILER? setting is set to LOCAL or COMBINATION, the
MODULAR BOILER SET is duplicated for each PID. Select
SPACE HEATING to set the ADD, SHED, MODULATE, and
MOD MAX values for the space heating PID. Then select DHW
HEATING to set the ADD, SHED, MODULATE, and MOD MAX
values for the DHW heating PID.
ADD BOILER DELAY
10 Minutes
0
– 60 Minutes
This is the delay time in 30sec intervals, before starting a new boiler.
Boiler #1 is started immediately after a call for heat. If a second
boiler needs to start, the ADD BOILER DELAY will need to expire.
The Add Boiler Delay is adjustable for each added boiler. It can be
varied for each individual boiler for specific control
schemes.
Selecting the 3 dots will open the variable delay settings menu.
SHED BOILER DELAY
2 Minutes
0
– 15 Minutes
This is the delay time in 30 second intervals, before stopping a
boiler. A boiler is stopped immediately when the top of the heat
band is exceeded. If a second boiler needs to stop, the
SHEDBOILER DELAY will need to expire before stopping.
MODULATE DELAY
TIME
10 Seconds
0
– 60 Minutes
This is the time the boiler remains in min-fire before it relinquishes
control to the modulation % signal.
MODULATION
MAXIMUM
– (LAST
FIRE)
70%
(25
– 100%)
This value represents the maximum % of input on the boilers if all
the available boilers are not firing. Once all boilers are firing, this
clamp is removed, and all boilers are allowed to modulate up to
100%. When this value is limiting the input an ‘*’ is displayed and
the “INPUT CLAMP” message is displayed in the STATUS screen.
This value is derived by multiplying twice the minimum fire rate of
the boiler with the least turndown (2* turndown (20% 5:1, 25% 4:1,
33% 3:1)).
In mixed boiler size configurations, more than (2) boilers in a
system, or when “bumps” in the temperature occur as boilers are
added and subtracted, this value may need adjustment. The
adjustments will help produce smooth temperature control when
each boiler is started and stopped. This method ensures that, once a
new boiler starts to fire, and holds its fire rate at the minimum
setting, it does not add its BTU output to a boiler already firing at
100%. The boilers cannot be fired starting @ 0%, but start at a
minimum (example: 20%) and introduce a minimum amount of
BTUs into the system. Section: SETUP & OPERATION
The MOD MAX value is also applied when using the AA terminal
for High Fire and when using the 4-20mA input for direct
modulation. When these demands for heat are used, the maximum
modulation the boiler can obtain when first starting is equal to the;
ADVANCED SETUP: MODULAR BOILER SET: MOD MAX –
LAST FIRE:. The timer value ADVANCED SETUP: MODULAR
BOILER SET: ADD BOILER DELAY is used in conjunction to
limit the modulation for this amount of time. Once the boiler has
fired and the ADD BOILER DELAY time expires, the full
modulation is available. This change is a protective means for
extending the life of the heat exchanger which may consistently be
exposed to thermal stress.
RELEASE
MODULATION
MAXIMUM
(DHW ONLY)
YES
YES/NO
In the DHW Heating tab, if set to Yes, the modulation % will not
exceed the MODULATION MAXIMUM set in the MODULATION
MAXIMUM – (LAST FIRE) setting.
