Belimo VRP-M - Functions

VRP-M VAV
Adaptive VAV controller
www.belimo.eu Product information S4-VRP-M VAV • en • v2.0 • 11.2006 • Subject to changes 9 / 28
Functions
Nominal volumetric flow 
nom

nom
corresponds to the maximum volumetric flow of the VAV unit at which the pressure drop
and noise are still within the permissible operating conditions. The 
nom
values are specified and
fixed-programmed by the unit manufacturer.
The volumetric flow actual value signal U5 is always in relation to 
nom
. Changes in the opera-
ting volumetric flow settings 
min
and 
max
therefore have no influence on the U5 voltage signal.
Creep flow limitation
Minimum setting limit 
max
Creep flow limitation (1)
This function suppresses differential pressure signals in the zero region. Undefined actuator mo-
vements in the 1 ... 6 Pa differential pressure range are prevented by this limitation. The working
range is physically limited owing to the dynamic behaviour of the differential pressure sensor and
the flow pattern of the media.
Sensor type Limitation
VFP-100 1 Pa
VFP-300 3 Pa
VFP-600 6 Pa
Unit manufacturer’s minimum setting limit (2)
Oversized VAV units can make control more difficult in the lowest differential pressure range.
A minimum volumetric flow, usually corresponding to a differential pressure of approximately
5 ... 12 Pa, is therefore specified for the units by the manufacturer. Functional restrictions in this
range can be avoided by complying with the unit manufacturer’s volumetric flow setting.
0/2
10
[V]
2
30%
0%
100%
100%
2
1
a
b
c
a
b
c
1
Start point
End point

nom
Volumetric flow [
nom
]
Volumetric flow actual value signal U5 [V]
Setting
[
min
]
Setting
[
max
]
Reference signal w
Optimum range
Setting with restriction
Setting with greatest
restriction
Creep flow limitation <2 Pa
Unit manufacturer’s minimum setting limit
0 ... 10 V
2 ... 10 V
adjustable