Carrier 50TCQA04 Installation Instructions Manual

Also see for WeatherMaker 50TCQA07: Installation instructions Installation instructions Service and maintenance instructions

52Space Temperature (SPT) Sensors —There are two types of SPT sensors available from Carrier,resistive input non-communicating (T55, T56, and T59)and Rnet communicating (SPS, SPPL, SPP, and SPPF)sensors. Each type has a variety of options consisting of:timed override button, set point adjustment, a LCDscreen, and communication tie in. Space temperature canbe also be written to from a building network or zoningsystem. However, it is still recommended that return airduct sensor be installed to allow stand-alone operation forback-up. Refer to the configuration section for details oncontroller configurations associated with space sensors.S 33ZCT55SPT, space temperature sensor with overridebutton (T--55)S 33ZCT56SPT, space temperature sensor with overridebutton and setpoint adjustment (T--56)S 33ZCT59SPT, space temperature sensor with LCD(liquid crystal display) screen, override button, andsetpoint adjustment (T--59)Use 20 gauge wire to connect the sensor to the controller.The wire is suitable for distances of up to 500 ft. Use athree--conductor shielded cable for the sensor and setpointadjustment connections. If the setpoint adjustment(slidebar) is not required, then an unshielded, 18 or 20gauge, two--conductor, twisted pair cable may be used.Connect T--55: See Fig. 49 for typical T--55 internalconnections. Connect the T--55 SEN terminals to the RTUOpen controller at J20--1 and J20--2. See Fig. 65.SENSENJ20-1J20-2C08460Fig. 65 -- RTU Open Controller T--55 SensorConnectionsConnect T--56: See Fig. 51 for T--56 internal connections.Install a jumper between SEN and SET terminals asillustrated. Connect T--56 terminals to the RTU Opencontroller at J20--1, J20--2 and J20--3 per Fig. 66.SEN J20-1J20-2SENSETJumperJ20-3SETC08461Fig. 66 -- RTU Open Controller T--56 SensorConnectionsConnect T--59: The T--59 space sensor requires aseparate, isolated power supply of 24 VAC. See Fig. 67for internal connections at the T--59. Connect the SENterminal (BLU) to the RTU Open controller at J20--1.Connect the COM terminal (BRN) to J20--2. Connect theSET terminal (STO or BLK) to J20--3.OR SET SENOPB COM- PWR+BLU (SPT)BLK (STO)24 VACSENSORWIRINGPOWERWIRINGBRN (COM)NOTE: Must use a separate isolated transformer.J20-3J20-2J20-1C10291Fig. 67 -- Space Temperature Sensor Typical Wiring(33ZCT59SPT)Indoor Air Quality (CO 2) Sensor —The indoor air quality sensor accessory monitors spacecarbon dioxide (CO2 ) levels. This information is used tomonitor IAQ levels. Several types of sensors are available,for wall mounting in the space or in return duct, with andwithout LCD display, and in combination with spacetemperature sensors. Sensors use infrared technology tomeasure the levels 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. 54 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 (American Wire Gage)twisted--pair cables (unshielded) to connect the separateisolated 24 vac power source to the sensor and to connectthe 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. 54. Connect the 4--20 mA terminal to theRTU Open controller at J4--2 and connect the SIG COMterminal to the RTU Open controller at J4--3. See Fig. 68.