Carrier 48TCA04---A12 appendix Burner Ignition, Limit Switch

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48TC

1.Remove manifold pressure tap plug from manifold and connect pressure gauge or manometer. (See Fig. 33.)

2.Turn on electrical supply.

3.Turn on unit main gas valve.

4.Set room thermostat to call for heat. If unit has two- stage gas valve, verify high-stage heat operation be- fore attempting to adjust manifold pressure.

5.When main burners ignite, check all fittings, mani- fold, and orifices for leaks.

6.Adjust high-stage pressure to specified setting by turning the plastic adjustment screw clockwise to in- crease pressure, counter-clockwise to decrease pres- sure.

7.For Two-Stage Gas Valves set room thermostat to call for low-stage heat. Adjust low-stage pressure to specified setting.

8.Replace regulator cover screw(s) when finished.

9.With burner access panel removed, observe unit heat- ing operation in both high stage and low stage opera- tion if so equipped. Observe burner flames to see if they are blue in appearance, and that the flames are approximately the same for each burner.

10.Turn off unit, remove pressure manometer and re- place the 1/8 in. pipe fitting on the gas manifold. (See Fig. 32.)

Limit Switch

Remove blower access panel. Limit switch is located on the fan deck. See Fig. 28.

Burner Ignition

Unit is equipped with a direct spark ignition 100% lockout system. Integrated Gas Unit Controller (IGC) is located in the control box. See Fig. 34. The IGC contains a self-diagnostic LED (light-emitting diode). A single LED (see Fig. 38) on the IGC provides a visual display of operational or sequential problems when the power supply is uninterrupted. When a break in power occurs, the IGC will be reset (resulting in a loss of fault history) and the indoor (evaporator) fan ON/OFF times will be reset. The LED error code can be observed through the viewport. During servicing refer to the label on the control box cover or Table 8 for an explanation of LED error code descriptions.

If lockout occurs, unit may be reset by interrupting power supply to unit for at least 5 seconds.

LOW HEAT

72,000 BTUH INPUT AND 60,000 BTUH INPUT

MEDIUM AND HIGH HEAT

115,000 BTUH INPUT,

150,000 BTUH INPUT, 90,000BTUH INPUT AND 120,000 BTUH INPUT

C06154

Fig. 35 - Spark Adjustment (04-07)

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Contents Table of Contents Safety ConsiderationsGeneral Unit Arrangement and AccessRoutine Maintenance What to do if you smell gasSeasonal Maintenance Supply FAN Blower Section Supply Fan Belt-DriveCondenser Coil Condenser Coil Maintenance and Cleaning RecommendationCooling Remove Surface Loaded Fibers Periodic Clean Water RinseRoutine Cleaning of Coil Surfaces One-Row CoilEvaporator Coil Refrigerant System Pressure Access PortsCleaning the Evaporator Coil Evaporator Coil Metering DevicesRefrigerant Charge To Use Cooling Charging ChartsPuronr R-410A Refrigerant No ChargeCooling Charging Charts Size Designation Nominal Tons ReferenceCooling Charging Charts C08229 C08437 C08438 C08439 Cooling Service Analysis Problem Cause RemedyConvenience Outlets Condenser-Fan AdjustmentTroubleshooting Cooling System CompressorController Smoke DetectorsSystem Unit Connect Primary TransformerSensor Smoke Detector LocationsCompleting Installation of Return Air Smoke Sensor Fiop Smoke Detector Wiring and ResponseController Alarm Test Sensor Alarm TestSensor Alarm Test Procedure Sensor and Controller TestsDirty Sensor Test Procedure Controller Alarm Test ProcedureDirty Controller Test Procedure To Configure the Dirty Sensor Test OperationDetector Cleaning Troubleshooting Compressor Protection Protective DevicesGAS Heating System Relief DeviceNatural Gas Manifold Pressure Ranges Fuel Types and PressuresNatural Gas Supply Line Pressure Ranges Liquid Propane Supply Line Pressure RangesFlue Gas Passageways Combustion-Air BlowerBurners and Igniters Cleaning and AdjustmentCheck Unit Operation and Make Necessary Adjust- ments Main BurnersLimit Switch Burner IgnitionLED Indication Error Code Description Orifice ReplacementLED Error Code Description Red LED-Status IGC Connections Orifice SizesLP Orifice Altitude Compensation* A04-A07Cont. Altitude Compensation* A08-A12 Altitude Compensation* A04-A06 Low NOx Units Troubleshooting Heating SystemMinimum heating entering air temperature Heating Service Analysis Problem Cause RemedyIGC Board LED Alarm Codes IGCPremierlinkt Control PremierLink ControllerPremierLink Wiring Schematic 55 Space Temperature Sensor Wiring Space Sensor Mode PremierLink Sensor UsageThermostat Mode 56 Internal ConnectionsLctb 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 RTU-MP Controller Inputs and Outputs OutputsSpace Temperature SPT Sensors RTU-MP T-55 Sensor ConnectionsIAQ Sensor SEN J4-2 COM J4-3 24 VAC Communication Wiring Protocols Connecting Discrete InputsPower Exhaust output RTU-MP Troubleshooting LEDs LEDs on the RTU-MP show the status of certain functionsTroubleshooting Alarms Alarms BACnet MS/TPRTU-MP Driver Manufacture Date Basic Protocol TroubleshootingModbus Code Name MeaningEconomizer Systems EconoMi$er IV Component LocationsEconoMi$er IV Wiring EconoMi$er EconoMi$er IV Input/Output LogicEconoMi$er IV Control Modes Supply Air Temperature SAT SensorOutdoor Air Lockout Sensor Outdoor Dry Bulb ChangeoverReturn Air Temperature or Enthalpy Sensor Mounting Location Outdoor Enthalpy ChangeoverMinimum Position Control Exhaust Setpoint AdjustmentIndoor Air Quality IAQ Sensor Input Occupancy Control Damper MovementThermostats Demand Control Ventilation DCVEconoMi$er IV Preparation CO2 Sensor ConfigurationEconoMi$er IV Sensor Usage Differential EnthalpyWiring Diagrams 48TC Typical Unit Wiring Diagram Power A06, 208/230-3-60 48TC Unit Wiring Diagram Control A06 PRE-START-UP START-UP, GeneralHeating CoolingMain Burners Ventilation Continuous FanSTART-UP, RTU-MP Control Field Service TestSTART-UP, Premierlink Controls Perform System Check-OutConfiguration Space Sensor Type InputsInput Input 1 FunctionHeating, Units Without Economizer Operating SequencesBase Unit Controls Cooling, Units Without Economizer Cooling, Unit With EconoMi$erHeating With EconoMi$er PremierLink Control48TC Available Cooling Stages OAT ≤ SPT 48TC 48TC Linkage Modes Loadshed Command Gas and Electric Heat UnitsRTU-MP Sequence of Operation SchedulingBACnet Schedule Always Occupied Default OccupancyLocal Schedule BAS On/OffIndoor Air Quality Power ExhaustEconomizer Torque Values Fastener Torque ValuesDemand Limit Serial Number Format Appendix I. Model Number SignificanceModel Number Nomenclature Position NumberAppendix II. Physical Data Physical Data Cooling TonsPhysical Data Cooling 48TC*A08 48TC*A09 48TC*A12Physical Data Heating LOW Appendix III. FAN Performance General Fan Performance NotesCFM RPM BHP Ton Horizontal SupplyTon Vertical Supply Medium Static Option High Static Option 48TC**05 Phase Ton Horizontal Supply 48TC**051506 48TC**05 Phase Ton Vertical Supply1493 148648TC**06 148248TC**06 Phase Ton Horizontal Supply 48TC**06 Phase Ton Vertical SupplyPhase Ton Horizontal Supply 48TC**071103 1143 11071124 1122 11621116 4971099 1093 11331247 5791263 1273Pulley Adjustment Unit MOTOR/DRIVE Motor Pulley Turns Open ComboRange RLA LRA Appendix IV. Electrical DataIFM TypeAppendix IV. Electrical Data FLARLA LRA IFM RangeEFF at FullFAN Motor Exhaust Combustion PowerNOM IFM No P.E Type DISC. SizeUnbalanced 3-Phase Supply Voltage NOMAppendix V. Wiring Diagram List Wiring DiagramsAppendix VI. Motormaster Sensor Locations 48TC*A04 Outdoor Circuiting48TC*A09/12 Outdoor Circuiting Catalog No 48TC---2SMUnit START-UP Checklist Preliminary Information

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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