Belimo VRD2 - TROX

Belimo VRD2
Supply/Extract Air Slave Control
for Dual Duct Unit TVM
Commissioning Signal
Adjuster ZEV Connections
Room temperature
controller
Cold duct controller VRD2
Warm duct controller VRD2
Slave controller
VRD2 (NMV-D2)
Operating mode S
Room temperature
controller
Operating mode M, F
Room Temperature
controller, switch
cabinet or step
distributor
11
Volume Flow Control of TVM Units
The two controllers fitted to the dual duct unit TVM (cold,
warm) must be wired by the customer as shown in the
circuit diagram opposite (including the 24 VAC/VDC
cross-connection).
The room temperature controller provides the cold duct
controller with its set point signal.
In most cases, the proportion of warm air is increased
from 0 to the required V · warm as a maximum set point.
The warm duct controller (V · total is measured) is therefore
set as a constant value controller and does not require
a control signal.
For a more detailed functional description, refer to the
TVM literature.
Supply/Extract Air Slave Control with
Dual Duct TVM
The actual value output signal U5 of the warm duct controller
is proportional to the total volume flow V · total. It
can therefore be used as the control signal for a slave
controller.
Commissioning Connections
It is advisable that the signal line for connecting the adjuster
ZEV is linked up in an easily accessible location.
This means that ceiling panels do not need be removed
in order to take measurements.
Suitable locations include: spare terminals in room temperature
controller or wall mounted enclosure.
It is important to ensure that the ground (and 24 V) is also
available. Therefore, a 3-wire connection is required to
the commissioning point connection.
IMPORTANT
The commissioning connection will also work if the U5 signal is used for slave circuits or monitoring. However,
the U5 signal differs from the actual value when the ZEV
unit is connected.
ZEV Function
The indicating lights come on when the control knob
settings match the current values. To adjust the control
mode, set the mode knob, for example to 0 - 10 VDC,
and press the Set button. The volume settings can only
be read.