York ZF150 Installation Manual

Also see for Predator ZF078: Technical guide

518674-YIM-C-0610Johnson Controls Unitary Products 37Enthalpy Set Point Adjustment• The enthalpy set point may now be set by selecting thedesired set point shown in the Enthalpy Set PointAdjustment Figure 27. Adjust as follows:• For a single enthalpy operation carefully turn the set pointadjusting screw (found on the damper control module) tothe "A", "B", "C" or "D" setting corresponding to the letteredcurve of the Enthalpy Set Point Adjustment Figure 28.• For a dual enthalpy operation, carefully turn the set pointadjusting screw fully clockwise past the "D" setting.Power Exhaust Damper Set Point (With Or Without PowerExhaust)• 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 the powerexhaust comes on is determined by the economizerdamper 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 accepts a+2 to +10 Vdc signal with respect to the (AQ1) terminal. Whenthe signal is below it's set point, the actuator is allowed tomodulate normally in accordance with the enthalpy and mixedair sensor inputs. When the AQ signal exceeds it's set pointsetting and there is no call for free cooling, the actuator isproportionately modulated from the 2 to 10 Vdc signal, with 2Vdc corresponding to full closed and 10 Vdc corresponding tofull 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 ControlVentilation 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.Figure 27: Enthalpy Set Point Chart40(4)70(21)50(10)55(13)60(16)65(18)35(2)45(7)75(24)80(27)35(2)40(4)45(7)50(10)55(13)60(16)65(18)70(21)75(24)80(27)85(29)85(29)90(32)90(32)105(41)110(43)100(38)95(35)95(35)100(38)105(41)110(43)APPROXIMATE DRY BULB TEMPERATURE - 0F (0 C)DDCCBBAACONTROLCURVECONTROL POINTAPPROX. 0F (0C)AT 50% RHADCB63 (17)73 (23)70 (21)67 (19)