32
Operation and maintenance instructions
Constant airflow
Flow control involves operating the air handling unit to
keep the preset airflow constant. The speed of the fans is
automatically regulated to provide correct airflow even if
the filters become clogged, diffusers are blocked, etc. The
exhaust air fan is controlled as a slave. A ratio between
exhaust and supply pressure can be configured in order
to create over, under or balanced pressure. For units with
backward fans, constant airflow can only be selected if
the “constant air kit” has been ordered as an option. The
desired setpoint is preset in (l/s, m³/h).
Setting
Range
Factory set-
ting
Airflow K1/K2/K3
0...max
Ratio exhaust/supply
5...999%
100%
Enable pressure alarm
No
Yes
Yes
D
P Supply/Exhaust
for pressure alarm
25...999Pa
200Pa
Initialisation airflow
(l/s, m³/h)
Pressure alarm initia-
lisation
No
Yes
Yes
Torque control
3 torque setpoints to be configured by the user (%TQ K1,
%TQ K2, %TQ K3). The setpoint is configured in % of the
maximal torque. The exhaust air fan is controlled as a
slave. A ratio between exhaust and supply pressure can
be configured in order to create over, under or balanced
pressure. The desired setpoint is preset in %. The Torque
control mode can be deactivated in the advanced setup.
Setting
Range
Factory setting
Airflow K1/K2/K3
0...100%
Ratio exhaust/supply
5...999%
100%
Demand control
The airflow desired is regulated in response to 0-10 V
input signals from an external sensor, such as a carbon
dioxide or a humidity sensor. The function can be config-
ured with a positive or a negative logic. A ratio between
exhaust and supply pressure can be configured in order to
create over, under or balanced pressure. The desired set-
point is preset in (l/s, m³/h). The “sleep factor” is a lower
operating rate for the unit (due to e.g. low occupancy)
that will be activated by speed “III “
Setting
Range
Factory
setting
Vmin
0...10V
1,0V
Vmax
0...10V
10,0V
m³/h ~Vmin
(l/s, m³/h)
m³/h ~Vmax
(l/s, m³/h)
Ratio exhaust/supply
5...999%
100%
Sleep factor on K3
10...100%
100%
Enable pressure alarm
No
Yes
Yes
D
P Supply/Exhaust
for pressure alarm
10...999Pa
200Pa
Initialisation airflow
(l/s, m³/h)
Pressure alarm initia-
lisation
No
Yes
Yes
Constant pressure
The airflow automatically varies to provide constant
pressure in the ducting. The duct pressure is measured by
an external in-duct pressure sensor which is connected
to the control unit’s BUS communication or the an ana-
logue 0...10V input. The function can be configured on
supply air, extract air or supply and extract air. The first
two configurations will have the second set of fans be
controlled as a slave. A ratio between exhaust and supply
pressure can be configured in order to create over, under
or balanced pressure. The initialisation will allow for an
automatic calculated pressure setpoint, determined by
the nominal airflow. The “sleep factor” is a lower operat-
ing rate for the unit (due to e.g. low occupancy) that will
be activated by speed “III “
Setting
Range
Factory
setting
Control
Supply
Exhaust
Exhaust
Supply
Ratio exhaust/supply
5...999%
100%
Sleep factor on K3
10...100%
100%
Pressure initialisation
Via Airflow
Via Pressure
Airflow
Start reference initia-
lisation
Yes
No
Yes
