Carrier 50TCQA Installation Instructions Manual

Also see for 48TC*D: Service and maintenance instructions Installation instructions

Contents

30enthalpy sensor and the (SR) terminal on the enthalpycontroller.NOTE: The enthalpy control must be set to the “D”setting for differential enthalpy control to work properly.Indoor Air Quality (CO2 sensor) — The indoor air qualitysensor accessory monitors space carbon dioxide (CO2 )levels. This information is used to monitor IAQ levels.Several types of sensors are available, for wall mountingin the space or in return duct, with and without LCDdisplay, and in combination with space temperaturesensors. Sensors use infrared technology to measure thelevels of CO2 present in the space air.The CO2 sensors are all factory set for a range of 0 to2000 ppm and a linear mA output of 4 to 20. Refer to theinstructions supplied with the CO2 sensor for electricalrequirements and terminal locations. See Fig. 38 fortypical CO2 sensor wiring schematic.To accurately monitor the quality of the air in theconditioned air space, locate the sensor near a return--airgrille (if present) so it senses the concentration of CO2leaving the space. The sensor should be mounted in alocation to avoid direct breath contact.Do not mount the IAQ sensor in drafty areas such as nearsupply ducts, open windows, fans, or over heat sources.Allow at least 3 ft (0.9 m) between the sensor and anycorner. Avoid mounting the sensor where it is influencedby the supply air; the sensor gives inaccurate readings ifthe supply air is blown directly onto the sensor or if thesupply air does not have a chance to mix with the room airbefore it is drawn into the return airstream.Wiring the Indoor Air Quality Sensor —For each sensor, use two 2--conductor 18 AWG (AmericanWire Gage) twisted--pair cables (unshielded) to connectthe separate isolated 24 vac power source to the sensorand to connect the sensor to the control board terminals.To connect the sensor to the control, identify the positive(4 to 20 mA) and ground (SIG COM) terminals on thesensor. See Fig. 38. Connect the 4--20 mA terminal toRTU--MP J4--2 and connect the SIG COM terminal toRTU--MP J4--3. See Fig. 53.SENCOMJ4-2J4-3IAQ Sensor24 VACC08462Fig. 53 -- RTU--MP / Indoor CO 2 Sensor(33ZCSENCO2) ConnectionsOutdoor Air Quality Sensor (PNO 33ZCSENCO2 plusweatherproof enclosure) — The outdoor air CO2 sensor isdesigned to monitor carbon dioxide (CO2 ) levels in theoutside ventilation air and interface with the ventilationdamper in an HVAC system. The OAQ sensor is packagedwith an outdoor cover. See Fig. 40. The outdoor air CO2sensor must be located in the economizer outside air hood.Wiring the Outdoor Air CO2 Sensor — A dedicated powersupply is required for this sensor. A two--wire cable isrequired to wire the dedicated power supply for the sensor.The two wires should be connected to the power supplyand terminals 1 and 2.To connect the sensor to the control, identify the positive(4 to 20 mA) and ground (SIG COM) terminals on theOAQ sensor. See Fig. 38. Connect the 4 to 20 mAterminal to RTU--MP J4--5. Connect the SIG COMterminal to RTU--MP J4--6.SENCOMJ4-5J4-6OAQ Sensor/RH Sensor24 VACC08463Fig. 54 -- RTU--MP / Outdoor CO 2 Sensor(33ZCSENCO2) ConnectionsOn 50TCQ units equipped with factory--installed SmokeDetector(s), the smoke detector controller implements theunit shutdown through its NC contact set connected to theunit’s CTB input. The FSD function is initiated via thesmoke detector’s Alarm NO contact set. The RTU--MPcontroller communicates the smoke detector’s trippedstatus to the BAS building control. See Fig. 30, thePremierLink wiring schematic.The Fire Shutdown Switch configuration,MENU→Config→Inputs→input 5, identifies thenormally open status of this input when there is no firealarm.Connecting Discrete InputsFilter StatusThe filter status accessory is a field--installed accessory.This accessory detects plugged filters. When installingthis accessory, the unit must be configured for filter statusby setting MENU→Config→Inputs→input 3, 5, 8, or 9to Filter Status and normally open (N/O) or normallyclosed (N/C). Input 8 or 9 is recommended for easy ofinstallation. Refer to Fig. 47 and Fig. 49 for wireterminations at J5.Fan StatusThe fan status accessory is a field--installed accessory.This accessory detects when the indoor fan is blowing air.When installing this accessory, the unit must beconfigured for fan status by settingMENU→Config→Inputs→input 3, 5, 8, or 9 to FanStatus and normally open (N/O) or normally closed (N/C).Input 8 or 9 is recommended for easy of installation. Referto Fig. 47 and Fig. 49 for wire terminations at J5.50TCQA