DEFAULT SETTINGS & MENU ITEM DESCRIPTIONS
HeatNet Control V3 3.x
Page 115
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
10mins
(0
– 15min)
This is the delay time in 30sec intervals, before starting a new boiler.
A boiler is started immediately after a call for heat. If a second boiler
needs to start, the ADD BOILER DELAY will need to expire before
starting. 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
2mins
(0-15min)
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 SHED
BOILER DELAY will need to expire before stopping.
MODULATE DELAY
TIME
10 secs
(0
– 60min)
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 4-20 mA 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.
MODULATION MODE
ADAPTIVE
If MODULATION MODE is set to ADAPTIVE on the MASTER
boiler, the MASTER lowers the system modulation rate of all
currently running boilers before a newly started boiler enters the
Main Valve state. Upon entering the Main Valve state of a newly
fired boiler, the MASTER waits the DELAY RELEASE time before
allowing the PID to resume modulation control. With MOD MODE
set to ORIG KN, The MASTER boiler keeps firing at the current
modulation rate when a new boiler is added and lets the PID adjust