Carrier 48/50PD05 User Manual

16a. (Configuration→ECON→UEFC = 0) -- DisabledWhen UEFC = 0, unoccupied free cooling is disabled.Cooling will only occur if the space exceeds theunoccupied setpoints.b. (Configuration→ECON→UEFC = 1) -- UnoccupiedWhen UEFC is set to 1, unoccupied free cooling canoccur throughout the entire unoccupied period. Thespace temperature must be higher then the mid--pointbetween the occupied cooling and heating set points.c. (Configuration→ECON→UEFC = 2) -- PreoccupancyWhen UEFC is set to 2, unoccupied free cooling canonly occur when the time until the next occupied periodis less than the Free Cool PreOcc Time (FC.TM) inminutes.2. Free Cool PreOcc Time(Configuration→ECON→FC.TM)FC.TM is the configuration that determines how manyminutes before occupancy that free cooling can occur whenset for Preoccupancy (UEFC = 2).3. 1.Free Cool Low Temp Limit(Configuration→ECON→FC.LO)Unoccupied free cooling cannot occur if the Outdoor AirTemperature (Temperature→ AIR.T→ OAT) is less thanFC.LO.Power ExhaustTo enable power exhaust set Power Exhaust Installed(Configuration→ECON→PE.EN) to YES. On the 48/50PD--05and 06 size units both power exhaust fans are wired together andare controlled by the configuration Power Exhaust Stage1 CFM(Configuration→ECON→PE1.C). When the Indoor Fan MaxSpeed CFM (Configuration→ECON→IDF.C) is set to the correctsupply duct CFM (either by fan tables or air balance report) thecontrol will calculate the outside air CFM based on outside airdamper position and Commanded Fan Speed(Outputs→FANS→F.SPD) to turn on the power exhaust when thecalculated outside air CFM reaches Power Exhaust Stage1 CFM(Configuration→ECON→PE1.C). The power exhaust will turnoff when the calculated outside air CFM falls below PowerExhaust Stage1 CFM (Configuration→ECON→PE1.C). ThePower Exhaust Stage2 CFM (Configuration→ECON→PE2.C) isnot currently used on the 48/50PD--05 and 06 units.Indoor Air Quality (IAQ)The ComfortLink TM control has the capability for severalmethods of demand ventilation control. Indoor air quality istypically measured using a CO2 sensor whose measurements aredisplayed in parts per million (ppm). Outdoor air quality may bemeasured with a CO2 sensor for indoor--outdoor differentialdemand ventilation control, or with other sensor types for theoutdoor air lockout function. The factory--installed indoor airquality CO2 sensor is mounted in the return section. Afield--installed indoor air quality CO2 sensor may be mounted inthe return or directly in the occupied space, per job requirements.The indoor air quality modes of operation can be affected by theIAQ Analog Input Config (Configuration→ AIR.Q→ IA.CF),IAQ Switch Input Config (Configuration→ AIR.Q→ IA.CF),OAQ Analog Input Config (Configuration→ AIR.Q→ OA.CF)and other related fan and limit configurations as described below.IAQ (Analog Input)The ComfortLink TM control is configured for indoor air qualitysensors which provide 4 to 20 mA signal for 0 to 2000 ppm CO2.If the sensor being used has a different range, the ppm displayrange must be reconfigured by entering new values for the IAQSensor Value at 4mA (Configuration→AIR.Q→I.4M) and IAQSensor Value at 20mA (Configuration→AIR.Q→I.20M).IA.CF = 0 (No IAQ)IA.CF = 0 signifies that there is no IAQ sensor installed. Thedamper will operate at the Econ Min at Max Fan Speed(Configuration→ECON→MP.MX) when the fan is at Supply FanMaximum Speed (Configuration→UNIT→FS.MX) and thedamper position will vary at other fan speeds as described in theCooling Mode with Economizer section below when the space isoccupied and the indoor fan is on.IA.CF = 1 (DCV)When IA.CF = 1 the IAQ algorithm is set for Demand ControlVentilation (DCV). During DCV, the damper modulates betweentwo user configurations depending upon the relationship betweenthe Indoor Air Quality (IAQ) and the Outdoor Air Quality (OAQ).The lower of these two positions is referred to as the Econo MinIAQ Position (Configuration→AIR.Q→AQ.MN) while the higheris referred to as the Econ Min at Max Fan Speed(Configuration→ECON→MP.MX). The Econo Min IAQPosition (Configuration→AIR.Q→AQ.MN) should be set to aneconomizer position that brings in enough fresh air to removecontaminates and CO2 generated by sources other than people.The Econ Min at Max Fan Speed(Configuration→ECON→MP.MX) should be set to aneconomizer position that brings in fresh air to remove contaminatesand CO2 generated by all sources including people when theindoor fan is operating at the Supply Fan Maximum Speed(Configuration→UNIT→FS.MX). The Econ Min at Max FanSpeed (Configuration→ECON→MP.MX) value is the designvalue for maximum occupancy.The ComfortLink TM control will begin to open the damper fromthe Econo Min IAQ Position (Configuration→AIR.Q→AQ.MN)position when the IAQ level begins to exceed the Outdoor AirQuality (OAQ) level by a configurable amount. This amount isreferred to as AQ Differential Low(Configuration→AIR.Q→AQD.L). When the differentialbetween IAQ and OAQ reaches AQ Differential High(Configuration→AIR.Q→AQD.H), the economizer position willbe at the Econ Min at Max Fan Speed(Configuration→ECON→MP.MX) when the indoor fan speed isat Supply Fan Maximum Speed(Configuration→UNIT→FS.MX). When the IAQ/OAQdifferential is between AQ Differential Low(Configuration→AIR.Q→AQD.L) and AQ Differential High(Configuration→AIR.Q→AQD.H), the control will modulate thedamper between Econ Min at Max Fan Speed(Configuration→ECON→MP.MX) and Econo Min IAQ Position(Configuration→AIR.Q→AQ.MN) in a linear manner as shownin Figure 3. At other fan speeds the economizer damper willoperate in the shaded area between the two economizer positioncurves but at the actual fan speed as indicated by Commanded FanSpeed (Outputs→FANS→F.SPD).IA.CF = 2 (Override IAQ)When IA.CF = 2, the IAQ algorithm maintains the damper at EconMin at Max Fan Speed (Configuration→ECON→MP.MX) whenthe indoor fan speed is at Supply Fan Maximum Speed(Configuration→UNIT→FS.MX) or in the shaded area of Figure3 when the indoor fan speed is at the Commanded Fan Speed(Outputs→FANS→F.SPD) until the override condition triggers.The override triggers when the IAQ/OAQ differential is greaterthan AQ Differential High (Configuration→AIR.Q→AQD.H).The IAQ Override Position (Configuration→AIR.Q→OVR.P).The economizer damper will return to the Econ Min at Max FanSpeed (Configuration→ECON→MP.MX) or MP.MX curve atother fan speeds when the IAQ/OAQ differential is less than theAQ Differential Low (Configuration→AIR.Q→AQD.L).The override algorithm will operate whenever the building isoccupied and the indoor fan is operating or whenever the IAQalgorithm has caused the indoor fan to operate. The IAQ AnalogFan Config (Configuration→AIR.Q→IA.FN) determines whetheror not the IAQ algorithm can turn on the indoor fan.If the indoor fan is not operating, the economizer position will bezero. If the override is not active and the building is unoccupied,the economizer position will be zero. The damper position may48/50PD