290699-YIM-B-0607
18
Unitary Products Group
Power exhaust is only available as a field installed
accessory.
ECONOMIZER AND POWER EXHAUST DAMPER
SET POINT 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 SET POINT ADJUSTMENT
The enthalpy set point may now be set by selecting the
desired setpoint shown in the Enthalpy Setpoint Adjust-
ment Figure 7. 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 7.
•
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.
•
With power exhaust option, each building pres-
surization 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.
Extreme care must be excercised in turning all
setpoint, maximium, and minimum damper
positioning adjustment screws to prevent twist-
ing them off.
