Setting Up Base Loading - HydroTherm HeatNet KN -6 User Information

CONTROL METHODS

Setting up base loading

The base load boiler is controlled using a set of contacts to
enable it (location J4). Enabling/Disabling this relay contact
can be done using any combination of (3) qualifiers to start
the boiler and (4) to stop the boiler. These qualifiers are:
Modulation %:
1.
a. START menu item: The relay contact will close
when the MOD % from the Master boiler exceeds
this value. ADVANCE SETUP:BASE LOADING:
START>MOD
b. STOP menu item: The relay contact will open
when the MOD % from the Master boiler falls
below this value. ADVANCE SETUP:BASE
LOADING: STOP<MOD
If the START>MOD value is set to a value
higher than the ADVANCED SETUP:MOD-
MAX: all boilers will be firing before this
modulation rate is reached. This will ensure
that all available boilers are firing before the
base load boiler relay is enabled.
Setting the : STOP<MOD to a % value slightly above
c.
the min fire rate % of the system will ensure that
the base load boiler will stop before the first
condensing boiler stops. This is due to the
Modulation rate being close to the min modulation
rate before the water temperature exceeds the top
of the heating band.
Outside Air Temperature:
2.
START menu item: The relay contact will close
a.
to enable the boiler when the OA T read from the
Outside Air Temperature sensor (if Equipped) falls
below this temperature. ADVANCE SETUP:BASE
LOADING: START< OA T
STOP menu item: The relay contact will open to
b.
disable the boiler when the OA T read from the
Outside Air Temperature sensor (if equipped) rises
above this value. ADVANCE SETUP:BASE
LOADING: STOP> OA T
If the OA T qualifier is used as the Start and
Stop qualifier, ensure that there is at least a
few degrees difference for hysteresis.
Return Water Temperature
3.
a. START menu item: The relay contact will
close to enable the boiler when the RET read
from the Return Water Temperature sensor (if
Equipped) falls below this temperature.
ADVANCE SETUP:BASE LOADING: START>
RET
b. STOP menu item: The relay contact will open
to disable the boiler when the RET
temperature read from the Return Water
Temperature sensor (if Equipped) rises above
this temperature. ADVANCE SETUP:BASE
LOADING: STOP< RET
4. FIRST:
a. STOP menu item: The relay contact will open
to disable the boiler when the temperature
exceeds the heating band. This gives the
result of stopping the Base Load boiler First.
Default setting.
Delay time
The DELAY TIME is also included to hold off starting the
boiler until the delay time is met. Once the start condition
qualifier term is met, the DELAY TIME will start counting
down. When the time expires, the base load relay contacts
will close. ADVANCE SETUP:BASE LOADING:DELAY
TIME. It is adjustable in a range of: 0 to 60 minutes.
Base Load Failsafe
If :
1) There are no boilers available to fire (offline or
faulted).
2) There are no boilers in local override.
3) There is a call for heat.
The J4 Base Load relay will close.
If a boiler becomes available and needs to fire, the Base
Load boiler will remain firing until the temperature exceeds
the band. This is provided to keep the system from entering
a no heat situation.
HeatNet Control V3 2.x
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