Carrier WeatherMaster 48HC07-12 Installation Instructions Manual

47Fig. 58 — Space Thermostat ConnectionsIf the 48HC unit has an economizer system and free-coolingoperation is required, a sensor representing Return Air Tem-perature must also be connected (field-supplied and installed).This sensor may be a T-55 Space Sensor (see Fig. 54) installedin the space or in the return duct, or it may be sensor P/N33ZCSENSAT, installed in the return duct. Connect this sensorto TB1-1 and TB1-3 per Fig. 55.CONFIGURE THE UNIT FOR THERMOSTATMODE — Connect to the CCN bus using a CCN service tooland navigate to PremierLink Configuration screen for Operat-ing Mode. Default setting is Sensor Mode (value 1). Changethe value to 0 to reconfigure the controller for ThermostatMode.When the PremierLink controller is configured for Thermo-stat Mode, these functions are not available: Fire Shutdown(FSD), Remote Occupied (RMTOCC), Compressor Safety(CMPSAFE), Supply Fan Status (SFS), and Filter PressureSwitch (FILTER).Economizer ControlsINDOOR AIR QUALITY (CO 2 ) SENSOR — The indoorair quality sensor accessory monitors space carbon dioxide(CO2) levels. This information is used to monitor IAQ levels.Several types of sensors are available, for wall mounting in thespace or in return duct, with and without LCD display, and incombination with space temperature sensors. Sensors use infra-red technology to measure the levels of CO2 present in thespace air.The CO2 sensors are all factory set for a range of 0 to 2000ppm and a linear mA output of 4 to 20. Refer to the instructionssupplied with the CO2 sensor for electrical requirements andterminal locations. See Fig. 59 for typical CO2 sensor wiringschematic.Fig. 59 — Indoor/Outdoor Air Quality (CO2) Sensor(33ZCSENCO2) — Typical Wiring DiagramTo accurately monitor the quality of the air in the condi-tioned air space, locate the sensor near a return-air grille (ifpresent) so it senses the concentration of CO2 leaving thespace. The sensor should be mounted in a location to avoid di-rect breath contact.Do not mount the IAQ sensor in drafty areas such as nearsupply ducts, open windows, fans, or over heat sources. Allowat least 3 ft (0.9 m) between the sensor and any corner. Avoidmounting the sensor where it is influenced by the supply air;the sensor gives inaccurate readings if the supply air is blowndirectly onto the sensor or if the supply air does not have achance to mix with the room air before it is drawn into the re-turn airstream.Wiring the Indoor Air Quality Sensor — For each sensor, usetwo 2-conductor 18 AWG (American Wire Gage) twisted-paircables (unshielded) to connect the separate isolated 24 vacpower source to the sensor and to connect the sensor to the con-trol board terminals.To connect the sensor to the control, identify the positive (4to 20 mA) and ground (SIG COM) terminals on the sensor. SeeFig. 59. Connect the 4-20 mA terminal to terminal TB1-9 andconnect the SIG COM terminal to terminal TB1-11. SeeFig. 60.Fig. 60 — Indoor CO 2 Sensor (33ZCSENCO2)ConnectionsRefer to PremierLink Controller Installation, Start-up, andConfiguration Instructions, for detailed configuration informa-tion.OUTDOOR AIR QUALITY SENSOR (P/N 33ZCSENCO2PLUS WEATHERPROOF ENCLOSURE) — The outdoorair CO2 sensor is designed to monitor carbon dioxide (CO2)levels in the outside ventilation air and interface with theJG 4-12J4-10J4-8Y1Y22R R46J4-6J4-4W2C810CSPACETHERMOSTATPLCTBTHERMOSTATW1TB1CTBTHERMOSTAT 8 7 6 5 4 3 2 12 1H G 24 VACOR24 VDCNC ALARMRELAYCONTACTSCOMNO }0-10VDCSIG COM4-20mA++-+ -J3 J4SEN J5-5J5-3COM911TB1TB1IAQ SensorPL24 VAC