Manual 2100-667
Page
9 of 19
CO
2
Control
For CO
2
-based control, add CO
2
sensor/controller
(Bard part #8403-067) to the wall and run additional
optional wires as shown in the wiring diagrams on
pages 11 and 12.
The CO
2
controller must also be reconfigured from the
standard default settings as shipped from the factory.
See page 13 for complete details.
Control System Notes
This ventilation package is set to meet the current
ASHRAE specifications for minimum occupied airflow
rates, with extended capability to meet demand
ventilation requirements. There are two different
provisions to optomize this control path. One is the
utilization of switch closures (occupancy and CO
2
demand) and the other is the utilization of occupancy
(switch closure) and modulating CO
2
.
Two Switch Application
Energizing the A terminal in the low voltage connection
box during occupied conditions will allow the minimum
occupied airflow rate to be set to meet ASHRAE
requirements. This can be accomplished by adjusting
Potentiometer R1 on the CRV control board by aligning
the damper position per the charts included on pages
14-17 (see Figure 7 on page 10). The factory default
blade position for this condition is set to position 3.
Energizing Terminal 5 (A is still energized) in the low
voltage connection box will then drive the damper open
to the CFM rate as set by Potentiometer R2 on the
CRV control board (see Figure 7). Refer to the proper
chart on pages 14-17 for the airflow to damper position
correlation. The factory default blade position for this
condition is set to position 4.5.
Modulating CO
2
Control
Wire the R power wire of the CO
2
control to A of the
low voltage terminal block, then energize A based upon
occupancy.
Connect the brown/white wire that is landed on the
PARK terminal in the CRV control board to the OCC
terminal of the CRV control board.
Once things are powered up and the CO
2
control has
equalized, adjust Potentiometer R7 to the minimum
damper open position to yield the desired occupied
airflow rates. The CO
2
control will then take over in
modulating the damper position to maintain the proper
CO
2
rates.
