VALLOX DIGIT SE / VKL
DIGIT SE part list
© VALLOX • We reserve the right to make changes without prior notification.
Supply air temperature
Supply air temperature can be controlled with either constant temperature
control or cascade control.
Supply air constant temperature control
The control unit directs the operation of post-heating unit
LP2
on the basis of
the measurement data given by temperature sensor
TE2
, aiming at keeping
supply air temperature at the temperature value set on control panel
H
(+10…+30 ºC).
Supply air cascade control
The control unit directs the operation of post-heating unit
LP2
on the basis of
the measurement data given by extract air sensor
TE4
, aiming at keeping
extract air temperature at the temperature value set on control panel
H
(+10…+30 ºC).
Heat recovery bypass
Heat recovery is enabled whenever post-heating has been switched on.
Automatic heat recovery bypass is active whenever post-heating has been
switched off and outdoor temperature is more than the set threshold value (to
be set b0…+25 ºC). In this case, the control unit directs the
operation of damper motor
FG
on the basis of measurement results given by
outdoor temperature sensor
TE3
and extract air temperature sensor
TE4
. The
aim is to get as cool supply air to the ventilation zone as possible. However,
heat recovery is always active when outdoor air temperature is below the set
threshold value, or whenever outdoor air is warmer than extract air.
Heat recovery anti-freezing
Active when outdoor temperature is below 0
°
C. The control / regulation
center of the unit directs the operation of the preheater (
LP1
) on the basis of
the measurement data supplied by the temperature sensors
TE1
and
TE3
. The
Voltage values for each fan speed:
0
0.20...1.25 VDC
1
1.75...2.25 VDC
2
2.75...3.25 VDC
3
3.75...4.25 VDC
4
4.75...5.25 VDC
5
5.75...6.25
VDC
6
6.75...7.25 VDC
7
7.75...8.25 VDC
8
8.75...10.00 VDC
Current values for each fan speed:
0
0.5...2.5 mA
1
3.5...4.5 mA
2
5.5...6.5
mA
3
7.5...8.5 mA
4
9.5...10.5 mA
5
11.5...12.5 mA
6
13.5...14.5 mA
7
15.5..16.5 mA
8
17.5...20.0 mA
Voltage and current signal values (selection in the motherboard)
Control of operation
Power supply to the unit can be controlled with a contactor in the distribution
panel if needed, e.g. with a timer programme. After starting, the unit first
operates at basic fan speed. After that power is adjusted based either on the
measurement data from air quality sensors and/or on manual control at the
control panel.
Fan speed adjustment
Manual control
Fan speed of the ventilation unit is controlled in 8 steps at control panel
H
.
Week clock control
Fan speed of the ventilation unit is controlled in 8 steps using the week clock
in control panel
H
. The week clock can be used to programme the desired fan
power option and the setpoint for supply air temperature for each day of the
week and each hour in the day.
Carbon dioxide and humidity control
The fan capacity of the ventilation unit is controlled in multiple steps
depending on loads, and based on the measurement results of the air quality
sensors (CO
2
and %RH sensors) located in the ventilation zone. The aim is to
keep carbon dioxide and/or humidity content below the threshold set at
control panel
H
. You may also choose automatic search for thehumidity
content threshold on the control panel
H
. One or more modes of control may
be used simultaneously - the mode demanding boosting is the dominant one.
Fan speed varies depending on load between the basic and maximum fan
speeds. The basic and maximum fan speeds can be set at the desired level at
the control panel
H
.
Control through voltage or current signal
The fan power of the ventilation unit is controlled in 8 steps with a voltage
signal of 0...10 VDC, or with a current signal of 0...20 mA. However, fan
power cannot be raised above the set maximum fan speed. Voltage or
current signal control is used to control basic fan speed. Because of this, fan
speed can only be raised when necessary, but not lowered by the manual,
CO
2
and %RH controls.
13
DESCRIPTION OF OPERATION DIGIT SE, electric radiator
aim is to prevent the risk of freezing and the stopping of the supply air fan
(
TF
). If the capacity of the preheater (
LP1
) is not sufficient, or if there is no
preheater, the control center intermittently stops the
TF
supply air fan on the
basis of the measuring data on the temperature sensors
TE1
and
TE3
, thereby
preventing the heat recovery cell from freezing. As soon as the risk of
frosting passes, the fan restarts automatically. The threshold temperature for
defrosting (-6…+15
°
C) and the difference area (+1…+10
°
C) can be set on
the control panel (
H
). When the
TF
fan stops, power supply to the
LP1
radiators is stopped and the
LP2
post-heating radiator continues to heat.
Overheating protection of the heating unit
The overheat protection thermostats
TS1
and
TS2
monitor the surface
temperature in the and
LP2
heating unit. If surface temperature exceeds the
threshold, overheat protection is triggered and power supply to the heating
unit is stopped. The
TS1
overheating protector is reset manually, and the
TS2
protector automatically.
Alarms
The pressure difference switches
PDS1
and
PDS2
monitor the pressure
difference between the supply and extract air sides. If the pressure
difference rises too high because of dirty filters or clogged ducts, an alarm
will be issued. This is indicated by a symbol ( ) in the main display of the
control panel. If the unit is not equipped with pressure difference switches,
the symbol ( ) appearing in the main display of the control panel reminds
of the need of servicing the unit. The reminder interval can be set between
1..15 months. The factory setting is 4 months. This function is always active.
The fault signal relay in the unit gives potential-free alarm indications on the
following fault conditions:
• Alarm of high carbon dioxide content (> 5000 ppm ) switches the relay
at 1-second intervals. The fans stop. This is acknowledged by switching
off the unit.
• In other fault situations, such as sensor faults and filter guard alarms
( ), the points of the relay close.
Booster or fireplace switch function
The booster or fireplace switch function of the ventilation unit is controlled
either at control panel
H
and/or separate switch
S
, which can be connected
to the connection box of the unit. The mode of operation of the switch is
selected at control panel
H
. The booster switch function raises fan speed to
the set maximum fan speed for 45 minutes. The fireplace switch stops the
extract air fan for 15 minutes and produces overpressure in the ventilation
zone.
LON remote monitoring control can be implemented with the VALLOX LON
converter.
