Carrier 48TCA04---A12 appendix IAQ Sensor SEN J4-2 COM J4-3 24 VAC

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return air sensor is wired to the enthalpy controller (HH57AC077). See Fig. 49.

To wire the return air enthalpy sensor, perform the following:

1.Use a 2-conductor, 18 or 20 AWG, twisted pair cable to connect the return air enthalpy sensor to the enthal- py controller.

2.At the enthalpy control remove the factory-installed resistor from the (SR) and (+) terminals.

3.Connect the field-supplied RED wire to (+) spade connector on the return air enthalpy sensor and the (SR+) terminal on the enthalpy controller. Connect the BLK wire to (S) spade connector on the return air enthalpy sensor and the (SR) terminal on the enthalpy controller.

NOTE: The enthalpy control must be set to the “D” setting for differential enthalpy control to work properly.

The enthalpy control receives the indoor and return enthalpy from the outdoor and return air enthalpy sensors and provides a dry contact switch input to the RTU-MP controller. A closed contact indicates that outside air is preferred to the return air. An open contact indicates that the economizer should remain at minimum position.

Indoor Air Quality (CO2 sensor) — The indoor air 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 the space or in return duct, with and without LCD display, and in combination with space temperature sensors. Sensors use infrared technology to measure the levels of CO2 present in the space air.

The CO2 sensors are all factory set for a range of 0 to 2000 ppm and a linear mA output of 4 to 20. Refer to the instructions supplied with the CO2 sensor for electrical requirements and terminal locations. See Fig. 50 for typical CO2 sensor wiring schematic.

To accurately monitor the quality of the air in the conditioned air space, locate the sensor near a return-air grille (if present) so it senses the concentration of CO2 leaving the space. The sensor should be mounted in a location to avoid direct breath contact.

Do not mount the IAQ sensor in drafty areas such as near supply ducts, open windows, fans, or over heat sources. Allow at least 3 ft (0.9 m) between the sensor and any corner. Avoid mounting the sensor where it is influenced by the supply air; the sensor gives inaccurate readings if the supply air is blown directly onto the sensor or if the supply air does not have a chance to mix with the room air before 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 separate isolated 24 vac power source to the sensor and 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 the sensor. See Fig. 50. Connect the 4-20 mA terminal to terminal TB1-9 and connect the SIG COM terminal to terminal TB1-7. See Fig. 64.

IAQ Sensor

SEN J4-2

COM J4-3 24 VAC

C08462

Fig. 64 - RTU-MP / Indoor CO2 Sensor

(33ZCSENCO2) Connections

Outdoor Air Quality Sensor (PNO 33ZCSENCO2 plus weatherproof enclosure) — The outdoor air CO2 sensor is designed to monitor carbon dioxide (CO2) levels in the outside ventilation air and interface with the ventilation damper in an HVAC system. The OAQ sensor is packaged with an outdoor cover. See Fig. 52. The outdoor air CO2 sensor must be located in the economizer outside air hood.

Wiring the Outdoor Air CO2 Sensor — A dedicated power supply is required for this sensor. A two-wire cable is required to wire the dedicated power supply for the sensor. The two wires should be connected to the power supply and terminals 1 and 2.

To connect the sensor to the control, identify the positive (4 to 20 mA) and ground (SIG COM) terminals on the OAQ sensor. See Fig. 50. Connect the 4 to 20 mA terminal to 48TC’s terminal TB1-11. Connect the SIG COM terminal to 48TC’s terminal TB1-13. See Fig. 65.

OAQ Sensor/RH Sensor

SEN J4-5

COM J4-6

24 VAC

C08463

Fig. 65 - RTU-MP / Outdoor CO2 Sensor

(33ZCSENCO2) Connections

On 48TC units equipped with factory-installed Smoke Detector(s), the smoke detector controller implements the unit shutdown through its NC contact set connected to the unit’s LCTB input. The FSD function is initiated via the smoke detector’s Alarm NO contact set. The PremierLink communicates the smoke detector’s tripped status to the CCN building control. See Fig. 23 for unit smoke detector wiring.

The Fire Shutdown Switch configuration, MENU→Config→Inputs→input 5, identifies the normally open status of this input when there is no fire alarm.

48TC

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Contents Safety Considerations Table of ContentsWhat to do if you smell gas Unit Arrangement and AccessRoutine Maintenance GeneralSeasonal Maintenance Supply Fan Belt-Drive Supply FAN Blower SectionCondenser Coil Condenser Coil Maintenance and Cleaning RecommendationCooling One-Row Coil Periodic Clean Water RinseRoutine Cleaning of Coil Surfaces Remove Surface Loaded FibersEvaporator Coil Metering Devices Refrigerant System Pressure Access PortsCleaning the Evaporator Coil Evaporator CoilNo Charge To Use Cooling Charging ChartsPuronr R-410A Refrigerant Refrigerant ChargeSize Designation Nominal Tons Reference Cooling Charging ChartsCooling Charging Charts C08229 C08437 C08438 C08439 Problem Cause Remedy Cooling Service AnalysisCompressor Condenser-Fan AdjustmentTroubleshooting Cooling System Convenience OutletsUnit Connect Primary Transformer Smoke DetectorsSystem ControllerSmoke Detector Locations SensorFiop Smoke Detector Wiring and Response Completing Installation of Return Air Smoke SensorSensor and Controller Tests Sensor Alarm TestSensor Alarm Test Procedure Controller Alarm TestTo Configure the Dirty Sensor Test Operation Controller Alarm Test ProcedureDirty Controller Test Procedure Dirty Sensor Test ProcedureDetector Cleaning Troubleshooting Relief Device Protective DevicesGAS Heating System Compressor ProtectionLiquid Propane Supply Line Pressure Ranges Fuel Types and PressuresNatural Gas Supply Line Pressure Ranges Natural Gas Manifold Pressure RangesCombustion-Air Blower Flue Gas PassagewaysMain Burners Cleaning and AdjustmentCheck Unit Operation and Make Necessary Adjust- ments Burners and IgnitersBurner Ignition Limit SwitchLED Indication Error Code Description Orifice ReplacementLED Error Code Description Red LED-Status Orifice Sizes IGC ConnectionsLP Orifice Altitude Compensation* A04-A07Cont. Altitude Compensation* A08-A12 Altitude Compensation* A04-A06 Low NOx Units Troubleshooting Heating SystemMinimum heating entering air temperature Problem Cause Remedy Heating Service AnalysisIGC IGC Board LED Alarm CodesPremierLink Controller Premierlinkt ControlPremierLink Wiring Schematic 55 Space Temperature Sensor Wiring PremierLink Sensor Usage Space Sensor Mode56 Internal Connections Thermostat ModeLctb Indoor CO2 Sensor 33ZCSENCO2 Connections PremierLink Filter Switch Connection Color Code Recommendations RTU-MP Control SystemRecommended Cables RTU-MP Multi-Protocol Control Board RTU-MP System Control Wiring Diagram Outputs RTU-MP Controller Inputs and OutputsRTU-MP T-55 Sensor Connections Space Temperature SPT SensorsIAQ Sensor SEN J4-2 COM J4-3 24 VAC Communication Wiring Protocols Connecting Discrete InputsPower Exhaust output RTU-MP Troubleshooting LEDs on the RTU-MP show the status of certain functions LEDsTroubleshooting Alarms BACnet MS/TP AlarmsRTU-MP Driver Code Name Meaning Basic Protocol TroubleshootingModbus Manufacture DateEconoMi$er IV Component Locations Economizer SystemsEconoMi$er IV Wiring EconoMi$er IV Input/Output Logic EconoMi$erOutdoor Dry Bulb Changeover Supply Air Temperature SAT SensorOutdoor Air Lockout Sensor EconoMi$er IV Control ModesOutdoor Enthalpy Changeover Return Air Temperature or Enthalpy Sensor Mounting LocationMinimum Position Control Exhaust Setpoint AdjustmentIndoor Air Quality IAQ Sensor Input Demand Control Ventilation DCV Damper MovementThermostats Occupancy ControlDifferential Enthalpy CO2 Sensor ConfigurationEconoMi$er IV Sensor Usage EconoMi$er IV PreparationWiring Diagrams 48TC Typical Unit Wiring Diagram Power A06, 208/230-3-60 48TC Unit Wiring Diagram Control A06 START-UP, General PRE-START-UPVentilation Continuous Fan CoolingMain Burners HeatingPerform System Check-Out Field Service TestSTART-UP, Premierlink Controls START-UP, RTU-MP ControlConfiguration Input 1 Function InputsInput Space Sensor TypeCooling, Unit With EconoMi$er Operating SequencesBase Unit Controls Cooling, Units Without Economizer Heating, Units Without EconomizerPremierLink Control Heating With EconoMi$er48TC Available Cooling Stages OAT ≤ SPT 48TC 48TC Scheduling Loadshed Command Gas and Electric Heat UnitsRTU-MP Sequence of Operation Linkage ModesBAS On/Off Always Occupied Default OccupancyLocal Schedule BACnet ScheduleIndoor Air Quality Power ExhaustEconomizer Torque Values Fastener Torque ValuesDemand Limit Position Number Appendix I. Model Number SignificanceModel Number Nomenclature Serial Number FormatPhysical Data Cooling Tons Appendix II. Physical Data48TC*A08 48TC*A09 48TC*A12 Physical Data CoolingPhysical Data Heating LOW General Fan Performance Notes Appendix III. FAN PerformanceCFM RPM BHP Ton Horizontal SupplyTon Vertical Supply Medium Static Option High Static Option 48TC**05 48TC**05 Phase Ton Horizontal Supply1486 48TC**05 Phase Ton Vertical Supply1493 15061482 48TC**0648TC**06 Phase Ton Vertical Supply 48TC**06 Phase Ton Horizontal Supply48TC**07 Phase Ton Horizontal Supply1122 1162 11071124 1103 11431093 1133 4971099 11161273 5791263 1247Unit MOTOR/DRIVE Motor Pulley Turns Open Combo Pulley AdjustmentType Appendix IV. Electrical DataIFM Range RLA LRAFLA Appendix IV. Electrical DataFull IFM RangeEFF at RLA LRAType DISC. Size Combustion PowerNOM IFM No P.E FAN Motor ExhaustNOM Unbalanced 3-Phase Supply VoltageWiring Diagrams Appendix V. Wiring Diagram List48TC*A04 Outdoor Circuiting Appendix VI. Motormaster Sensor LocationsCatalog No 48TC---2SM 48TC*A09/12 Outdoor CircuitingPreliminary Information Unit START-UP Checklist

48TCA04---A12 specifications

The Carrier 48TCA04---A12 is a high-efficiency rooftop air conditioning unit designed for commercial and industrial applications. Known for its reliability and performance, this model features advanced technologies that cater to diverse climate control needs.

One of the standout features of the Carrier 48TCA04---A12 is its excellent energy efficiency, which adheres to the stringent standards set by the U.S. Environmental Protection Agency. The unit utilizes a highly efficient scroll compressor combined with state-of-the-art heat exchanger technology, allowing it to operate with minimal energy consumption while providing powerful cooling capabilities.

The unit comes equipped with a robust and durable design, built to withstand various environmental conditions. Its weather-resistant cabinet is constructed from high-quality materials, ensuring long-lasting performance even in harsh climates. Additionally, the unit features a galvanized steel structure with a powder-coated finish, further enhancing its resistance to corrosion and wear.

In terms of technologies, the Carrier 48TCA04---A12 incorporates advanced controls that promote optimal performance. The unit supports Carrier's smart connectivity options, facilitating remote monitoring and adjustments via smart devices. This feature ensures convenient energy management and allows maintenance teams to access performance data, leading to proactive service interventions.

Another important characteristic of this unit is its quiet operation. The design includes sound-reducing insulation and a well-engineered airflow system, minimizing noise levels to create a more comfortable indoor environment. This is particularly important for commercial spaces such as offices and retail environments, where a tranquil atmosphere is critical for customer satisfaction and productivity.

The Carrier 48TCA04---A12 also offers diverse application flexibility, making it suitable for various locations, from small retail stores to large warehouses. With several tonnage options available, users can select a model that perfectly aligns with their specific cooling needs. Additionally, the unit can be easily integrated with existing HVAC systems, providing a seamless solution for upgrading or retrofitting older installations.

To sum up, the Carrier 48TCA04---A12 rooftop air conditioning unit stands out due to its exceptional energy efficiency, durable construction, advanced technology, and quiet operation, making it a reliable choice for commercial and industrial cooling solutions. Its flexibility and smart technology integrations ensure that it meets a wide range of climate control requirements effectively.
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