Camus Hydronics Valiant FT VA0080, Manual

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Figure 39: DHW Pump or 3-way valve settings for Valiant FT
Mode Requirements
For DHW mode 4, there are 3 sensors required for
operation.
When any of these sensors are not enabled or are in the
open/shorted state DHW mode 4 cannot generate a
demand.
The following sensors are required to be available for DHW
mode 4:
• DHW sensor
•
Supply sensor
• Return sensor
Mode Requirements
For DHW mode 4 a demand is present when DHW tapping
is detected.
During a demand the burner is started based on the
T_DHW
temperature.
Tap start detection
Tap detection for DHW mode 4 is done using the DHW
sensor. DHW tapping is detected when:
•
The
T_DHW
temperature drops more than
Tap_Drop_Delta
per second.
• The T_DHW temperature drops below DHW_Setpoint
– Tap_Detect_Hyst_Down .
When a DHW tap demand has been detected two timers
are started:
• Tap_Detect_Hold_Time Minimum time that the DHW
tap demand must remain active.
• Incr_Hyst_Up_Time
Time in which the burner uses a
double hysteresis up on the setpoint.
Tap stop detection
When the internal tap detection hold timer has elapsed the
tap detection can be ended. Under the following conditions
a tap stop is detected:
•
The delta between the
Supply
and
Return
sensor is
smaller than
Tap_Stop_Delta_Supply_Return
.
•
The delta between the
Return
and
DHW
sensor is
greater than
Tap_Stop_Delta_Return_DHW
.
Burn demand
The burner is PID modulated in relation to the T_DHW
temperature to the DHW_Setpoint .
The burner is started for DHW mode 4 when the following
conditions are met:
• The T_DHW temperature drops below DHW_Setpoint
– DHW_Hyst_Down.
The burner is stopped for DHW mode 4 when the following
conditions are met:
• The T_DHW temperature rises over DHW_Se
DHW_Hyst_Up.
• During the Incr_Hyst_Up_Time period the
burner stops when the DHW sensor reaches
a temperature of
DHW_Se
(DHW_Hyst_Up * 2).
Utilized sensors for DHW Modes 0 to 4
The following table shows the sensor availability for all the
DHW control modes. Sensors not mentioned in the table
are optionally available for other functions.
Sensor DHW Mode
0 1 2 3 4
Supply O M M O M
Return O O O O M
DHW --- M --- M M
Outdoor O O O O O
0-10 V O O O O O
Water Flow DHW O O O O O
RT Switch O O M O O
Table 21: Sensors required for the various DHW Modes
5.6 SAFETY AND SYSTEM FUNCTIONS
5.6.1 On-board Physical Lockout Reset
The Valiant FT control board is equipped with a push button
and a 2 color (red/green) LED.
The green LED will be ON when the control is operational.
The red LED will be ON when the control has a lockout
error.
The control can be reset with the push button when control
has a lockout error.