VALLOX 252 D
3
INSTRUCTIONS FOR USE
Control panel
Carbon dioxide sensor
Humidity sensor
Ventilation control
The ventilation unit can be controlled completely with the control panel included in
the delivery, or with an optional LON converter.
In addition, optional carbon dioxide and humidity sensors can be used for demand
controlled ventilation.
Fan capacity can also be controlled with voltage or current signals.
Ventilation control with control panel
The following ventilation control functions can be performed at the control panel:
Ventilation rate regulation
• Capacity regulation (8 positions).
• Setting the basic fan speed and the maximum fan speed. Ventilation rate cannot
be set lower than the basic fan speed. When CO
2
and/or %RH adjustments are
activated, capacity cannot be adjusted to exceed the maximum fan speed. When
CO
2
and %RH adjustments are not enabled, fan speed can be raised to speed 8.
Supply air temperature control functions
• Switching the electric or water-circulated post-heating unit on or off.
• Setting the desired supply air temperature (+10˚C...+30˚C).
• Choosing the control mode for desired supply air temperature (constant
temperature control, cascade control).
Preheating
• Setting the control temperature for the preheating unit (-6˚C...+15˚C exhaust air).
The maximum number of control panels is 3. If two or more control panels are
used, the most recent control function is the one that is valid.
Ventilation control with carbon dioxide sensor (option)
• In carbon dioxide control, VALLOX 252 D adjusts fan speed so as to keep the
carbon dioxide content in the ventilation zone below the setpoint. If two or more
sensors are used, fan speed is adjusted in accordance with the highest measuring
result.
• 1...5 optional carbon dioxide sensors may be connected to the VALLOX 252 D
unit.
• The adjustment is switched on / off and, if needed, the setpoint (500...2000ppm)
is defined on the control panel. The factory setting is 900 ppm.
• While control is activated, you can use the control panel to raise fan speed to the
maximum speed and to lower it to the basic fan speed.
In carbon dioxide control, maximum fan speed limitation is enabled.
Ventilation control with relative humidity sensor
• When the relative humidity control is activated, VALLOX 252 D adjusts fan speed,
keeping %RH low compared to humidity level in the ventilation zone. When two
sensors are in use, fan speed is adjusted according to the higher measuring result.
• VALLOX 252 D can be equipped with one or two optional relative humidity
sensors.
• The sensor is switched on / off on the control panel.
• The setpoint of humidity control changes automatically according to the humidity
conditions. You can switch the automatic search off and change the setpoint
manually (1…99 %RH). Automatic search is the factory setting.
• When ventilation is controlled with a %RH sensor, you can raise fan speed to the
maximum level from the control panel, and lower it to the basic fan speed.
In humidity control, maximum fan speed limitation is enabled.
When the unit is taken into use for the first time, it will take the program 3...10 hours to search
the setpoint. During this time, humidity control is not active.
HUMIDITY SENSOR
CARBON DIOXIDE
SENSOR
CONTROL PANEL
LON CONVERTER
