RBI FUTERA XLF Series, Руководство по управлению, Страница: 32 / 128

DHW METHODS HeatNet Control V3
Page 32
This method requires a 10k thermistor connected to the
DHW Sensor input of a DHW MASTER, or a standalone
boiler, and a DHW tank. This method does not use a
HEADER sensor. The DHW temperature is maintained by
the space heating PID for backwards compatibility. With
this method the OR OVR input does not function as a DHW
enable and is not used. The Heat Demand input is used to
enable/disable DHW heating operations.
The System pump is enabled on the MASTER as long as the
Heat Demand input is closed. The selected network boiler’s
Local pump is engaged when there is a call for DHW
heating by the MASTER. This allows for a DHW
loop/buffer and A DHW tank that can be heated using the
MASTER’s DHW pump (Reverse/Return only) or each
boiler’s Local Pump/Valve supplying this loop/buffer.
Boilers are started as long as the tank’s water temperature is
below the (DHW SETPOINT – LOWER BAND). The first
boiler is started immediately. The next boiler(s) is started
after the ADD BOILER DELAY time expires. Boilers are
not added when the temperature is above the (DHW
SETPOINT – LOWER BAND) and below the UPPER
BAND. Once the UPPER BAND is exceeded, boilers will
shut off based on the SHED BOILER DELAY TIME.
Setting up this method is done via the menu in:
SETTINGS: DOMESTIC HOT WATER.
Connect a
10k thermistor from the DHW tank’s sensor
well to J10B terminals on the DHW MASTER, or
standalone boiler. Wire a pump or valve from the Local
pump of each DHW boiler.
A DHW call is when the DHW temperature is
below the (DHW SETPOINT – LOWER BAND)
or when the DHW temperature is below the (DHW
SE UPPER BAND) and boilers are
firing.
The Masters System pump (Normally Open) will
always be enabled as long as the Heat Demand
input is closed.
The MASTER’s DHW pump (Normally Open)
relay contacts will close during a DHW call. Once
the call has ended, the last DHW boiler stops firing,
and the programmed post-purge time has expired,
the MASTER’S DHW contacts will open. In this
application the Masters DHW pump can be used
globally.
After a DHW call ends the Local pump will remain
on during a post purge pump cycle until the post
purge timer expires.
DHW Only Method 1 Set Up:
1. Enter the DOMESTIC HOT WATER menu on
the MASTER boiler. In the BOILER MODE
selection, enter DHW ONLY . The MASTER uses
this method as a DHW system much like a space
heating system.
MEMBER boilers may set the BOILER MODE to
LOCAL and go offline to perform secondary DHW
heating, but the MASTER setting must be set to
AUTO/OFF .
Setting the BOILER MODE to COMBINATION
using this method may cause erratic operation and the
DHW pump to not be enabled.
2. Change the DHW SETPOINT to the desired target
temperature of the water in the tank. Once the control
determines there is a call for DHW, the DHW
SETPOINT is loaded and the MASTER boiler will
target the setpoint.
3. Now, change the LOWER BAND to the desired
temperature (DHW SETPOINT – LOWER BAND)
below which boilers are to be added. This setting
corresponds to the minimum water temperature
required in the tank. DHW heating will be initiated
when the DHW tank’s water temperature is below the
temperature (DHW SETPOINT – LOWER BAND).
How long the temperature of the tank stays below the
temperature (DHW SETPOINT – LOWER BAND)
is
used to determine when boilers are started along with
the ADD BOILER DELAY TIME.
4. Next, change the UPPER BAND to the desired
temperature (DHW SE UPPER BAND)
above which boilers are to be shed. This setting is the
maximum tank temperature. Setting the SHED
BOILER DELAY TIME correctly will limit the
maximum tank temperature to the (DHW SETPOINT
+ UPPER BAND). Setting the SHED BOILER
DELAY TIME = 0 will shut off all boilers
immediately once the (DHW SE UPPER
BAND) is exceeded.
5. Now, determine if the DHW Priority is required by
the menu item
PUMP PRIORITY? . Setting this
value to YES will turn OFF the system pump when
the DHW mode is active. Setting this value to NO
leaves the system pump on.
6. Select the amount of time for the POST PURGE of
the DHW pump. This is the time that the MASTER’S
DHW pump relay remains energized after the DHW
SETPOINT has been satisfied.
A. The Local pump will remain on during a post
purge pump cycle until the post purge timer
expires.