RBI FUTERA XLF Series, Control Manual

Page: 28 / 128

CONTROL METHODS HeatNet Control V3
Page 28
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:
1. Modulation % :
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.
c. Setting the: STOP<MOD to a % value slightly
above 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.
2. Outside Air Temperature :
a. START menu item : The relay contact will close 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
b. STOP menu item : The relay contact will open to
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
c.
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
d. 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
3. 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.
If there are no boilers available to fire (offline or faulted) and
there are no boilers in local override, and 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.
Domestic Hot Water Methods
Domestic Hot Water control is supported using (6) methods.
When using the Domestic Hot Water methods, the wire
jumper, JPS1 on each control board providing Domestic Hot
Water, must be cut to limit the boiler’s maximum output
temperature to 200F. Refer to
Figure 26 for control input,
refer to Figure 57 for sensor inputs, and Figure 45 for pump
output locations.