Camus Hydronics Valiant FT VA0080, Manual, Page: 33 / 79

26
All other safety and control functions associated with the
boiler will react normally to adverse condition and override
control of the analog signal to prevent an upset condition.
A heat request will be generated by an input of 1.5 volts or
higher. The fan speed modulation will occur between 2.0
and 9.0 volts. The request for heat will be removed when
the voltage drops below 1 volt.
Figure 38: Valiant FT Analog Input Control
Description Programming Instructions
•
Boiler operates at
variable firing rate
decided by the
analog input signal
•
Modulates on
Boiler inlet sensor
• Heat demand is
generated when
the
ENABLE/DISABLE
contact is closed
and an external
signal provided.
1. On digital display, use UP
and DOWN buttons to scroll
to “CH Demand”.
2. Press center button to select
“CH Demand” and UP and
DOWN buttons to scroll to
ENABLE. Press center button
again to confirm selection.
3. Place Remote/Local switch
into “REMOTE”.
4. CH Setpoint can be changed
by selecting CH Setpoint on
the Digital Display screen.
Anti-Cycling Time
This function sets a time limit the boiler must wait before it
is allowed to fire up again after having been switched OFF
by reaching the setpoint and going over the Upper
Hysteresis band. This is to prevent constant short cycling of
the boiler.
This time limit can be set by going into settings as below.
The following table shows the sensor availability for all the
CH control modes. Sensors not mentioned in the table are
optionally available for other functions.
Sensor CH Mode
0 1 2 3 4 5
Supply M M M M M ---
Return O O O O O ---
DHW O O O O O ---
Outdoor --- M M O O ---
0-10 V O O O O M ---
Water Flow DHW O O O O O ---
RT Switch M M M M M ---
Table 19: Sensors required for the various CH Modes
5.5 DHW PROGRAMMING INSTRUCTIONS
This appliance is a boiler with its main function being solely
for space heating. Any re-channeling of the hot water from
the central heating loop for domestic water heating
purposes must be field engineered, conforming to the local
safety codes. This unit is not certified to be used as a
domestic water heater!
DHW Mode 0:
No Domestic Hot Water
DHW Mode 1: Storage with sensor
DHW Mode 2: Storage with thermostat
DHW Mode 3: Instantaneous water heating with plated
heat exchanger, flow switch and DHW-out sensor
DHW Mode 4: Instantaneous water heating with plated
heat exchanger and DHW-out sensor
DHW Modes 5-8: DHW Modes 5 to 8 are not applicable.
5.5.1 DHW Mode 0: No domestic hot water
No Domestic Hot Water is available.
The DHW Out sensor does not need to be connected.
5.5.2 DHW Mode 1: Storage with sensor
In this mode of operation, a sensor is used to monitor and
maintain the temperature in the tank. When needed, the
Valiant FT will activate a DHW pump or a 3-way valve to
divert heated water towards the tank to raise its
temperature.
The temperature in the tank is measured with the DHW
sensor and the setpoint set with the parameter
DHW_Store_Setpoint .
Once the sensor drops below the lower hysteresis
(
DHW_Store_Hyst_Down
), the control detects a DHW
demand and starts the general pump, as well as the DHW
pump, to divert the water from space heating to the DHW
tank.