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York PREDATOR BP120 User Manual

Page 21

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66307-YIM-B-0606

Unitary Products Group

21

For a dual enthalpy operation, carefully turn the set point
adjusting screw fully clockwise past the "D" setting.

POWER EXHAUST DAMPER SET POINT (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 pressurization
requirement will be different. The point at which the
power exhaust comes on is determined by the econo-
mizer 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 set point, the actuator is allowed
to modulate normally in accordance with the enthalpy and
mixed air sensor inputs. When the AQ signal exceeds it's set
point 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 set point (Demand Control Ven-
tilation Set Point) 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

Sensor Kit Part # 2AQ04700424

Replace the top rear access panel on the unit.

FIGURE 20 - ENTHALPY SET POINT CHART