Assortment / System Description

Fan
-
Powered Box
Outputs
19
A6V10866237_en--_b_08 159 | 275
Description Name Default value
Supply air VAV maximum air flow for ventilation VavSuAflMaxVnt 100 [m
3
/h]
27.78 [l/s]
Supply air VAV minimum air flow for ventilation VavSuAflMinVnt 0 [m
3
/h]
0.00 [l/s]
Maximum fan speed for ventilation FanSpdMaxVnt 100 [%]
Minimum fan speed for ventilation FanSpdMinVnt 50 [%]
19.3.1 External volume air flow control
A differential pressure sensor is typically connected to the VAV actuator for an
application with external volume flow control. Which in turns also implements
volume flow control. In this case, the application in the DXR2 controls only the
room temperature and forwards the setpoint for volume flow control to the VAV
actuator.
The present damper position is determined in all cases by DXR2 and provided
to the central function for optimizing the supply air fan.
19.3.2 Internal volume flow control
A differential pressure sensor is typically connected to the DXR2 for an
application with internal volume flow control. It can be implemented using the
integrated pressure sensor on the DXR2 or an analog sensor. DXR2 then also
operate volume flow control in addition to temperature control.
The present damper position is determined in all cases by DXR2 and provided
to the central function for optimizing the supply air fan.
19.4 Outputs
At the fan powered box outputs, KNX PL-Link VAV actuators, analog VAV
actuators, analog damper actuators (with supplemental differential pressure
sensor), or 3-position damper actuators (with supplemental differential
pressure sensor) can be controlled via Triac outputs.
Analog outputs on the DXR2 control modulating fans.
19.5 Switch-off delay
The switch off of a fan is delayed for a specific period on applications that have
electric heating coils/reheaters. This cools down the electric heating
coils/reheater with circulating air. The switch-on/switch-off time can be
configured.
Description Name Default value
Switch-off delay holding signal for air volume flow
heating
DlyOffAflHldH 30 [s]