Functional description
Installation instructions VRC 470 0020116690_00
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8
8.2.5 Setting the frost protection delay
Menu ¬ Installer level ¬ System configuration
[System ----] ¬ Frost protect. delay
This function allows you to delay activation of the frost
protection function by setting a delay time.
The frost protection function guarantees frost protec-
tion in the heating system for all connected heating cir-
cuits in mode "Off" and "Eco" (outside the set period).
If the outside temperature falls below 3 °C, the set-back
temperature is applied as the target room temperature.
The heating circuit pump is switched on.
The frost protection function is also activated when the
measured room temperature falls below the preset set-
back temperature (regardless of the measured outside
temperature).
If you set a delay time, the frost protection function is
suppressed during this period.
This function is only effective if the "Eco" setting is
selected for the "System off mode" function.
8.2.6
Setting the pump blocking time
Menu ¬ Installer level ¬ System configuration
[System ----] ¬ Pump Blocking Time
To save energy, you can set the pump blocking time dur-
ing which the heating circuit pump remains deactivated.
For each heating circuit, the controller checks if the
measured flow temperature is 2 K above the calculated
target value. If this is the case for 15 minutes, the pump
of the heating circuit in question is deactivated for the
set blocking time. The mixer remains in its current posi-
tion.
The blocking time set is reduced as a function of the
outside temperature.
Example:
Blocking time set = 60 minutes
Outside temperature 20 °C = Blocking time 60 min.
Outside temperature 3 °C = Blocking time 5 min.
8.2.7
Setting the maximum pre-heating time
Menu ¬ Installer level ¬ System configuration
[System ----] ¬ Max. pre-heat
This function allows you to start the heating function for
the heating circuits a set amount of time before the first
period of the day, so that the target room temperature
is already reached at the beginning of the first period.
The start of heating is determined as a function of the
outside temperature (OT):
OT
–20 °C : preset duration of the pre-heat time
OT
+20 °C : no pre-heat time
The duration of the pre-heat time is interpolated linearly
between these two values.
8.2.8
Setting the maximum pre-switch-off time
Menu ¬ Installer level ¬ System configuration
[System ----] ¬ Max. pre-switch-off
You can avoid unnecessary heating in the heating sys-
tem immediately before a defined switch-off time by set-
ting a pre-switch-off time.
The controller calculates the actual period depending on
the outside temperature.
Set the maximum period desired by the owner here.
If the outside temperature is at -20 °C, no pre-switch-off
occurs.
If the outside temperature is +20 °C, the set, maximum
pre-switch-off time comes into effect.
With outside temperatures in the range of -20 °C to
+20 °C the controller calculates a value corresponding to
a linear curve between -20 °C and +20 °C.
i
The calculation is made for the day already
started. The earliest start time is 0:00 hours.
If a pre-switch-off time of 120 minutes is set
and a period of 0:00 to 01:00 hours, the pre-
switch-off time does not start at 23:00 hours
on the previous day, but at 0:00 hours.
8.2.9
Setting the temperature threshold for
constant heating
Menu ¬ Installer level ¬ System configuration
[System ----] ¬ OT constant heating
"Outside temperature constant heating" is a configura-
ble temperature value below which heating using the
target room temperature/heating curve assigned to the
heating circuit is constant outside the programmed
period.
The function allows you to define a value for the outside
temperature at which a set-back or total shut-down
should no longer occur.
