RBI FUTERA XLF Series, Control Manual

Page: 60 / 128

OPTIONAL FEATURES HeatNet Control V3
Page 60
Outdoor Reset
The Outdoor reset feature allows the water setpoint
temperature to change dynamically with the outside air
temperature. It also provides an adjustable temperature that
shuts the boiler (or boiler system) down when the outside
temperature rises above it.
WATER TEMP
LOW OA TEMP
180 °F
10 °F
Water temp @
outside air temp
WATER TEMP
HIGH OA TEMP
140 °F
70 °F
Water temp @
outside air temp
WWS Setpoint 72 °F
Outside air temperature
where Warm Weather
Shutdown occurs
WARM WEATHER SD=ON If set to ON here
Figure 47 Outdoor reset curve, typical
The above chart shows how the water temperature setpoint
changes with the Outside air temperature. The four values of
180, 10 and 140, 70 are the default values:
The chart depicts what the water temperature setpoint will
equal with a corresponding outside air temperature. At an
outside temperature of 10F and below, the water temperature
setpoint will be limited to 180F. With an outdoor temperature
of 70F and above, the water temperature will be limited to
140F. The water temperature setpoint will track along the
charts plotted line with corresponding outside temperatures.
The OR OVR (Outdoor Reset Override) input on J12A can
be used to override this Outside Air Setpoint and maintain
the water setpoint at the LOCAL or SYSTEM SETPOINT
value when a contact is closed across this input. This can be
used as a Domestic Hot Water demand input.
Another function of the OUTDOOR RESET is the
Winter/Summer mode ((W)arm (W)eather (S)hutdown).
With the WWS SETPOINT set to 72F and WARM
WEATHER SD set to ON, the boiler/system will enter
summer shutdown when the Outside Air temperature rises
above 72F. While in this state, the OR OVR input on J12A
can be used to bring the boiler/system on to maintain the
water setpoint at the LOCAL or SYSTEM SETPOINT value.
During WWS operation, the System pump will not be
enabled just the Local pump unless the SETUP: SYSTEM
PUMP: OVR ENAB IN WWS is set to ON. This is the
System Pump Priority mode. When SETUP: SYSTEM
PUMP: OVR ENAB IN WWS is set to OFF, the system
pump will not come on while in WWS with the OR OVR
override input closed.
Sensors
The H-Net control supports a standard 10K thermistor (Type
ACI/10K-CP). These sensors can be calibrated to the control
by entering the sensor menu and placing a precision 10k
resistor on an input.
Sensors should be wired using a twisted
shielded pair cable of 18-22 AWG wire.
Immersion sensors must have wells.
Stack Temperature
If the boiler is a Fusion PVC model, the Stack sensor is
preconfigured and will only operate with a working 10k stack
sensor and HeatNet Firmware designated as PVC. Switch
S5.3 should be set to the 10K STACK position and S5.4 set
to NONE. A warning will occur at 158F and higher, and an
alarm will occur at 168F and higher. If the stack temperature
is above the warning temperature, the boiler will be limited to
½ the called for input rate until the alarm temperature is
reached. At this point the boiler will shut down. The boiler
will then be allowed to restart when the Stack temperature
drops below 158F.
The version 3 control also supports an optional 1k platinum
stack sensor. If the Stack Sensor is present, a warning will
occur at 325F and greater. During the Warning condition, for
every degree F over the warning temperature of 325F, the
boiler’s input will be limited by 4% until the boiler is running
at low fire. If the SETUP: AUX FUNCTIONS: HEAT
EXCHANGER: ALARM TYPE: is set to” FAULT” the
boiler will halt and the Alarm relay will close when the Stack
temperature exceeds 350F. The boiler will then be allowed
to restart when the Stack temperature drops below 325F.
130
140
150
160
170
180
190
10 70
Wa
te
r Tem
p
Outside Temp
WATER TEMPERATURE SETPOINT