York Predator MagnaDRY DR090 Series Installation Manual

Also see for PREDATOR MagnaDRY DR090: Technical guide Installation manual

264276-XIM-B-1208Johnson Controls Unitary Products 25located between the condenser coil section and the main unitcabinet, if the unit has factory installed options. If fieldinstalled accessories are being installed all parts necessaryfor the installation comes in the accessory.ECONOMIZER AND POWER EXHAUST SET POINTADJUSTMENTS AND INFORMATIONRemove the top rear access panel from the unit. Locate theeconomizer control module, where the following adjustmentswill be made.MINIMUM POSITION ADJUSTMENT• Check that the damper blades move smoothly withoutbinding; carefully turn the Minimum Position Adjustscrew (found on the damper control module) fully clock-wise and then set the thermostat indoor fan switch to theON position and then OFF or energize and de-energizeterminals “R” to “G”.• With the thermostat set to the indoor fan ON position orterminals “R” to “G” energized, turn the Minimum Posi-tion Adjusting screw (located on the damper controlmodule) counterclockwise until the desired minimumdamper position has been attained.ENTHALPY SET POINT ADJUSTMENTThe enthalpy set point may now be set by selecting thedesired set point shown in the Enthalpy Set Point AdjustmentFigure 22. Adjust as follows:• For a single enthalpy operation carefully turn the setpoint adjusting screw (found on the damper controlmodule) to the "A", "B", "C" or "D" setting correspondingto the lettered curve of the Enthalpy Set Point Adjust-ment Figure 22.• For a dual enthalpy operation, carefully turn the set pointadjusting 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 AirAdjustment Screw fully clockwise. This will allow 2ndstage cooling to operate.• With power exhaust option, each building pressurizationrequirement will be different. The point at which thepower exhaust comes on is determined by the econo-mizer damper position (Percent Open). The Exhaust AirAdjustment Screw should be set at the Percent Open ofthe economizer damper at which the power exhaust isneeded. It can be set from 0 to 100% damper open.INDOOR AIR QUALITY AQIndoor Air Quality (indoor sensor input): Terminal AQ acceptsa +2 to +10 Vdc signal with respect to the (AQ1) terminal.When the signal is below it's set point, the actuator is allowedto modulate normally in accordance with the enthalpy andmixed air sensor inputs. When the AQ signal exceeds it's setpoint setting and there is no call for free cooling, the actuatoris proportionately modulated from the 2 to 10 Vdc signal, with2 Vdc corresponding to full closed and 10 Vdc correspondingto full open. When there is no call for free cooling, the damperposition 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 fullopen position based on the highest call from either the mixedair sensor input or the AQ voltage input.• Optional CO2 Space Sensor Kit Part # 2AQ04700324• Optional CO2 Sensor Kit Part # 2AQ04700424Replace the top rear access panel on the unit.Extreme care must be exercised in turning all setpoint, maximum and minimum damper positioningadjustment screws to prevent twisting them off.