Volumetric flow controller VAQS
®
08/23 - 9
Construction subject to change.
No return possible!
09.05.2019
Version:
Technical data for Belimo components
Measured value collection and control function
The measured values are collected by two measuring rods fa-
vourable to the flow. The measuring openings are distributed
over the measuring rods according to the median line method.
The pressure differential formed on the measuring rods is deter-
mined by means of a dynamic or static measuring sensor. From
these measuring results the middle value is formed, which gives
a measured variable for the volume flow. The controller com-
pares the actual value signal with the set point and sends a start
signal to the electric actuator which adjusts the controller devi-
ation independent of pressure changes in the duct network.
Attention:
The volumetric flow controllers equipped with the Belimo con-
trol type LMV/NMV-D3-MF are delivered as standard with a
SCHAKO 2 - 10 V DC drive (w-signal). Upon activation with 2 V
DC, the V
min
volume is set. The V
min
volumes can be seen from
the V
min
/ V
max
tables. When the V
min
volume drops below the
values shown in the V
min
/ V
max
table, then the control function
and the output of the U5 signal is no longer guaranteed for me-
trology reasons. Airtight sealing to DIN 1751 can be achieved by
means of a 0V actuator signal or via a positive control. This pos-
itive control "CLOSED" must be implemented on-site via a switch
contact.
Upon customer request, the volumetric flow controller equipped
with the Belimo control type LMV/NMV-D3-MF can also be de-
livered with the drive 0-10 V DC. However, please note that in
this case the positive control "CLOSED" can be implemented via
a diode, see page 10.
Operating control Belimo components
Positive control damper "CLOSED"
Energy saving in areas not in use by closing the supply and re-
turn air volumetric flow controller. If the input Y is connected to
terminal 1 (see page 10) via an on-site switch for the
operating
range 2-10 V DC
, the drive will move the damper to the
CLOSED
position
. The drive will also close the damper if the setpoint val-
ue for the minimum volumetric flow V
min
has been set to 0%,
and the control signal corresponds to the value V
min
. This func-
tion does not correspond to the function of positive control
"CLOSED" via the switch contact.
Positive control damper "OPEN"
Supports smoke extraction or is used as a safety position. The
volumetric flow controller is in this case inactive, and the damp-
er is driven to the mechanical open position.
V
min
control to min. volumetric flow
Depending on requirement or by not assigning them, individual
areas can be set to stand-by operation. In this way, minimum
room flushing with greatly reduced energy expenditure is
achieved.
V
max
control to max. volumetric flow
Individual or several rooms are supplied for a short period with
a maximum volumetric flow. This allows airing, night cooling
and quick heating to be implemented.
Continuous operation
As a function of the continuous command signal and the pro-
grammed operating area (2 - 10 V; 0 - 10 V) the LMV/NMV-D3-
MF will regulate the volumetric flow between the set values of
V
min
and V
max
.
Constant operation
If terminal 3 (Y signal) has not been assigned, the air volume set
on the V
min
potentiometer will be set to a constant volume.
VAV-Compact (LMV/NMV-D3-MF)
The operation control is effected via the drive input w/z. The
possible functions depend on the selected operating mode "2-10
V" or "0-10 V" The diagrams below show the possible settings.
