Installation manual

035-19084-001-D-0504
26 Unitary Products Group
OPTIONAL POWER EXHAUST/BAROMETRIC RELIEF
DAMPER AND RAIN HOOD
The instructions for the power exhaust/barometric relief
damper and rain hood can be found in form 035-
19856-000. The exhaust fan, all supporting brackets,
angles, and the wiring are factory installed as part of
the power exhaust option.
All of the components, including the dampers, hard-
ware, and mounting instructions are shipped in a single
package external from the unit. The hood must be field
assembled and installed.
Power exhaust is not available as a field installed
option.
OPTIONAL ECONOMIZER AND POWER EXHAUST
DAMPER SETPOINT ADJUSTMENTS AND INFORMATION
Remove the economizer access panel from the unit.
Loosen but do not remove the two panel latches.
Locate the economizer control module, where the fol-
lowing adjustments will be made.
Check that the damper blades move smoothly without
binding; carefully turn the Minimum Position Adjusting
screw (found on the damper control module) fully
clockwise and then set the thermostat indoor fan switch
to the on position and then off, or energize and de-
energize terminals "R" to "G".
MINIMUM POSITION ADJUSTMENT
With thermostat set to indoor fan on position, or termi-
nals "R" to "G" energized, turn the Minimum Position
Adjusting screw (located on the damper control mod-
ule) counterclockwise until the desired minimum
damper position has been attained.
ENTHALPY SETPOINT ADJUSTMENT
The enthalpy setpoint may now be set by selecting the
desired setpoint shown in the Enthalpy Setpoint Adjust-
ment Figure 9. Adjust as follows:
• For a single enthalpy operation carefully turn the
setpoint adjusting screw (found on the damper
control module) to the "A", "B", "C" or "D" setting
corresponding to the lettered curve of the Enthalpy
Setpoint Adjustment Figure 9.
• For a dual enthalpy operation, carefully turn the
setpoint adjusting screw fully clockwise past the
"D" setting.
POWER EXHAUST DAMPER SETPOINT (WITH OR WITH-
OUT POWER EXHAUST)
• With no power exhaust option, adjust the Exhaust
Air Adjustment Screw fully clockwise. This will
allow 2nd stage cooling to operate.
• With power exhaust option, each building pressur-
ization requirement will be different. The point at
which the power exhaust comes on is determined
by the economizer damper position (Percent
Open). The Exhaust Air Adjustment Screw should
be set at the Percent Open of the economizer
damper at which the power exhaust is needed. It
can be set from 0 to 100% damper open.
INDOOR AIR QUALITY
Indoor Air quality (indoor sensor input): Terminal AQ
accepts a +2 to +10 Vdc signal with respect to the
(AQ1) terminal. When the signal is below it's setpoint,
the actuator is allowed to modulate normally in accor-
dance with the enthalpy and mixed air sensor inputs.
When the AQ signal exceeds it's setpoint setting and
there is no call for free cooling, the actuator is propor-
tionately modulated from the 2 to 10 Vdc signal, with 2
Vdc corresponding to full closed and 10 Vdc corre-
sponding to full open. When there is no call for free
cooling, the damper position is limited by the IAQ Max
damper position setting. When the signal exceeds it's
setpoint (Demand Control Ventilation Setpoint) setting
and there is a call for free cooling, the actuator modu-
lates from the minimum position to the full open posi-
tion based on the highest call from either the mixed air
sensor input or the AQ voltage input.
• Optional CO
2
Space Sensor Kit Part #
2AQ04700224
• Optional CO
2
Sensor Kit Part # 2AQ04700124
Replace the economizer access panel.
Extreme care must be excercised in turning all
setpoint, maximum, and minimum damper
positioning adjustment screws to prevent twist-
ing them off.