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VCCX2 Controller Technical Guide
Building Pressure Control Output
The Building Pressure Control Output is a 0-10 VDC or 2-10
VDC signal sent from the VCCX2 Controller. When using the
output for direct building pressure control (output signal rises on
a rise in building pressure), the output signal can be connected to
either a Variable Frequency Drive (VFD) controlling an exhaust
fan or to a damper actuator controlling an exhaust damper
(both by others). When used in this manner, the output signal
must be configured for direct acting operation. See
Figure 23,
this page
for detailed wiring of the Building Pressure Control
Output Signal.
When using this output for Reverse Building Pressure Control
(output signal rises on a fall in building pressure), a damper
actuator controlling an OA damper or supply fan VFD would
be used.
When using the OA damper for Reverse Building Pressure
Control, the output signal must be configured for reverse acting
operation. A building pressure sensor connected to AI5 on the
VCCX2 Controller is used to sense and control the signal to the
building pressure output. The Building Static Pressure Sensor
must be connected in order for the building pressure output to
operate correctly.
CAUTION:
VFD units can cause large transient noise spikes
that can cause interference to be propagated
on other electronic equipment. Use shielded
wire wherever possible and route all sensor
and controller wiring away from the VFD and
the HVAC unit electrical wiring.
Note:
Both types of building pressure control are shown.
Only one type of building pressure control device
may be used on each HVAC unit.
VCCX2 Controller
Building Pressure Control Damper Actuator
(by others - Belimo Actuator Shown)
Note:
Belimo Actuator wiring showing.
Consult factory for other manufacturer
wiring instructions.
Caution:
The VFD unit must be configured for 0-10
VDC input. The input resistance at the VFD
must not be less than 1k ohms when
measured at the VFD terminals with all input
wires removed.
(by others)
Building Pressure Control Exhaust Fan VFD
Note:
Wire to the VFD using 18 gauge minimum two-
conductor twisted pair with shield cable. Wire
shield to GND as shown.
Shield
Size transformer for correct total load.
VCCX2 Controller = 15 VA
0-10 VDC input
from AO4
Figure 23: Building Pressure Control Output Wiring
WIRING
Building Pressure Control Outputs