66396-YIM-C-1004
Unitary Products Group
13
OPTIONAL ECONOMIZER/MOTORIZED DAMPER RAIN
HOOD
The instruction for the optional economizer/motorized
damper rain hood can be found in form 035-19854-
000. Use these instructions when field assembling an
economizer rain hood onto a unit. The outdoor and
return air dampers, the damper actuator, the damper
linkage, the outdoor and return air divider baffles, and
all the control sensors are factory mounted as part of
the "Factory installed" economizer option.
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
accessory.
OPTIONAL ECONOMIZER AND POWER EXHAUST
DAMPER SET POINT ADJUSTMENTS AND INFORMA-
TION
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
terminals "R" to "G" energized, turn the Minimum
Position Adjusting screw (located on the damper
control module) counterclockwise until the desired
minimum damper position has been attained.
ENTHALPY SET POINT ADJUSTMENT
The enthalpy set point may now be set by selecting the
desired setpoint shown in the Enthalpy Setpoint Adjust-
ment Figure 6. Adjust as follows:
•
For a single enthalpy operation carefully turn the
set point 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 6.
•
For a dual enthalpy operation, carefully turn the set
point 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 AQ
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
accordance 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 proportionately modulated from the 2 to 10 Vdc
signal, with 2 Vdc corresponding to full closed and 10
Vdc corresponding 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 modulates from the minimum position to the
full open position based on the highest call from either
the mixed air sensor input or the AQ voltage input.
•
Optional CO
2
Space Sensor Kit Part #
2AQ04700324
•
Optional CO
2
Unit Sensor Kit Part # 2AQ04700424
Replace the economizer access panel.
Extreme care must be exercised in turning all
setpoint, maximum, and minimum damper
positioning adjustment screws to prevent twist-
ing them off.
