Carrier 48TCA04---A12 appendix Damper Movement, Thermostats, Occupancy Control

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To determine the minimum position setting, perform the following procedure:

1.Calculate the appropriate mixed air temperature using the following formula:

(TO x 100OA ) + (TR x 100RA ) =TM

TO = Outdoor-Air Temperature

OA = Percent of Outdoor Air

TR = Return-Air Temperature

RA = Percent of Return Air

TM = Mixed-Air Temperature

As an example, if local codes require 10% outdoor air during occupied conditions, outdoor-air temperature is 60_F, and return-air temperature is 75_F.

(60 x .10) + (75 x .90) = 73.5_F

2.Disconnect the supply air sensor from terminals T and T1.

3.Ensure that the factory-installed jumper is in place across terminals P and P1. If remote damper positioning is being used, make sure that the terminals are wired according to Fig. 59 and that the minimum position potentiometer is turned fully clockwise.

4.Connect 24 vac across terminals TR and TR1.

5.Carefully adjust the minimum position potentiometer until the measured mixed air temperature matches the calculated value.

6.Reconnect the supply air sensor to terminals T and T1.

Remote control of the EconoMi$er IV damper is desirable when requiring additional temporary ventilation. If a field-supplied remote potentiometer (Honeywell part number S963B1128) is wired to the EconoMi$er IV controller, the minimum position of the damper can be controlled from a remote location.

To control the minimum damper position remotely, remove the factory-installed jumper on the P and P1 terminals on the EconoMi$er IV controller. Wire the field-supplied potentiometer to the P and P1 terminals on the EconoMi$er IV controller. (See Fig. 81.)

Damper Movement

Damper movement from full open to full closed (or vice versa) takes 21/2 minutes.

Thermostats

The EconoMi$er IV control works with conventional thermostats that have a Y1 (cool stage 1), Y2 (cool stage 2), W1 (heat stage 1), W2 (heat stage 2), and G (fan). The EconoMi$er IV control does not support space temperature sensors. Connections are made at the thermostat terminal connection board located in the main control box.

Occupancy Control

The factory default configuration for the EconoMi$er IV control is occupied mode. Occupied status is provided by the black jumper from terminal TR to terminal N. When unoccupied mode is desired, install a field-supplied

timeclock function in place of the jumper between TR and N. When the timeclock contacts are closed, the EconoMi$er IV control will be in occupied mode. When the timeclock contacts are open (removing the 24-v signal from terminal N), the EconoMi$er IV will be in unoccupied mode.

Demand Control Ventilation (DCV)

When using the EconoMi$er IV for demand controlled ventilation, there are some equipment selection criteria which should be considered. When selecting the heat capacity and cool capacity of the equipment, the maximum ventilation rate must be evaluated for design conditions. The maximum damper position must be calculated to provide the desired fresh air.

Typically the maximum ventilation rate will be about 5 to 10% more than the typical cfm required per person, using normal outside air design criteria.

A proportional anticipatory strategy should be taken with the following conditions: a zone with a large area, varied occupancy, and equipment that cannot exceed the required ventilation rate at design conditions. Exceeding the required ventilation rate means the equipment can condition air at a maximum ventilation rate that is greater than the required ventilation rate for maximum occupancy. A proportional-anticipatory strategy will cause the fresh air supplied to increase as the room CO2 level increases even though the CO2 setpoint has not been reached. By the time the CO2 level reaches the setpoint, the damper will be at maximum ventilation and should maintain the setpoint.

In order to have the CO2 sensor control the economizer damper in this manner, first determine the damper voltage output for minimum or base ventilation. Base ventilation is the ventilation required to remove contaminants during unoccupied periods. The following equation may be used to determine the percent of outside air entering the building for a given damper position. For best results there should be at least a 10 degree difference in outside and return-air temperatures.

(TO x 100OA ) + (TR x 100RA ) =TM

TO = Outdoor-Air Temperature

OA = Percent of Outdoor Air

TR = Return-Air Temperature

RA = Percent of Return Air

TM = Mixed-Air Temperature

Once base ventilation has been determined, set the minimum damper position potentiometer to the correct position.

The same equation can be used to determine the occupied or maximum ventilation rate to the building. For example, an output of 3.6 volts to the actuator provides a base ventilation rate of 5% and an output of 6.7 volts provides the maximum ventilation rate of 20% (or base plus 15 cfm per person). Use Fig. 82 to determine the maximum setting of the CO2 sensor. For example, an 1100 ppm setpoint relates to a 15 cfm per person design. Use the 1100 ppm curve on Fig. 82 to find the point when the CO2 sensor output will be 6.7 volts. Line up the point on the

48TC

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Contents Safety Considerations Table of ContentsRoutine Maintenance Unit Arrangement and AccessGeneral What to do if you smell gasSeasonal Maintenance Supply Fan Belt-Drive Supply FAN Blower SectionCooling Condenser Coil Maintenance and Cleaning RecommendationCondenser Coil Routine Cleaning of Coil Surfaces Periodic Clean Water RinseRemove Surface Loaded Fibers One-Row CoilCleaning the Evaporator Coil Refrigerant System Pressure Access PortsEvaporator Coil Evaporator Coil Metering DevicesPuronr R-410A Refrigerant To Use Cooling Charging ChartsRefrigerant Charge No ChargeSize Designation Nominal Tons Reference Cooling Charging ChartsCooling Charging Charts C08229 C08437 C08438 C08439 Problem Cause Remedy Cooling Service AnalysisTroubleshooting Cooling System Condenser-Fan AdjustmentConvenience Outlets CompressorSystem Smoke DetectorsController Unit Connect Primary TransformerSmoke Detector Locations SensorFiop Smoke Detector Wiring and Response Completing Installation of Return Air Smoke SensorSensor Alarm Test Procedure Sensor Alarm TestController Alarm Test Sensor and Controller TestsDirty Controller Test Procedure Controller Alarm Test ProcedureDirty Sensor Test Procedure To Configure the Dirty Sensor Test OperationDetector Cleaning Troubleshooting GAS Heating System Protective DevicesCompressor Protection Relief DeviceNatural Gas Supply Line Pressure Ranges Fuel Types and PressuresNatural Gas Manifold Pressure Ranges Liquid Propane Supply Line Pressure RangesCombustion-Air Blower Flue Gas PassagewaysCheck Unit Operation and Make Necessary Adjust- ments Cleaning and AdjustmentBurners and Igniters Main BurnersBurner Ignition Limit SwitchLED Error Code Description Orifice ReplacementLED Indication Error Code Description Red LED-Status Orifice Sizes IGC ConnectionsCont. Altitude Compensation* A08-A12 Altitude Compensation* A04-A07LP Orifice Minimum heating entering air temperature Troubleshooting Heating SystemAltitude Compensation* A04-A06 Low NOx Units 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 Recommended Cables RTU-MP Control SystemColor Code Recommendations 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 Power Exhaust output Connecting Discrete InputsCommunication Wiring Protocols RTU-MP Troubleshooting LEDs on the RTU-MP show the status of certain functions LEDsTroubleshooting Alarms BACnet MS/TP AlarmsRTU-MP Driver Modbus Basic Protocol TroubleshootingManufacture Date Code Name MeaningEconoMi$er IV Component Locations Economizer SystemsEconoMi$er IV Wiring EconoMi$er IV Input/Output Logic EconoMi$erOutdoor Air Lockout Sensor Supply Air Temperature SAT SensorEconoMi$er IV Control Modes Outdoor Dry Bulb ChangeoverOutdoor Enthalpy Changeover Return Air Temperature or Enthalpy Sensor Mounting LocationIndoor Air Quality IAQ Sensor Input Exhaust Setpoint AdjustmentMinimum Position Control Thermostats Damper MovementOccupancy Control Demand Control Ventilation DCVEconoMi$er IV Sensor Usage CO2 Sensor ConfigurationEconoMi$er IV Preparation Differential EnthalpyWiring Diagrams 48TC Typical Unit Wiring Diagram Power A06, 208/230-3-60 48TC Unit Wiring Diagram Control A06 START-UP, General PRE-START-UPMain Burners CoolingHeating Ventilation Continuous FanSTART-UP, Premierlink Controls Field Service TestSTART-UP, RTU-MP Control Perform System Check-OutConfiguration Input InputsSpace Sensor Type Input 1 FunctionBase Unit Controls Cooling, Units Without Economizer Operating SequencesHeating, Units Without Economizer Cooling, Unit With EconoMi$erPremierLink Control Heating With EconoMi$er48TC Available Cooling Stages OAT ≤ SPT 48TC 48TC RTU-MP Sequence of Operation Loadshed Command Gas and Electric Heat UnitsLinkage Modes SchedulingLocal Schedule Always Occupied Default OccupancyBACnet Schedule BAS On/OffEconomizer Power ExhaustIndoor Air Quality Demand Limit Fastener Torque ValuesTorque Values Model Number Nomenclature Appendix I. Model Number SignificanceSerial Number Format Position NumberPhysical 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 PerformanceTon Vertical Supply Ton Horizontal SupplyCFM RPM BHP Medium Static Option High Static Option 48TC**05 48TC**05 Phase Ton Horizontal Supply1493 48TC**05 Phase Ton Vertical Supply1506 14861482 48TC**0648TC**06 Phase Ton Vertical Supply 48TC**06 Phase Ton Horizontal Supply48TC**07 Phase Ton Horizontal Supply1124 11071103 1143 1122 11621099 4971116 1093 11331263 5791247 1273Unit MOTOR/DRIVE Motor Pulley Turns Open Combo Pulley AdjustmentIFM Appendix IV. Electrical DataRange RLA LRA TypeFLA Appendix IV. Electrical DataEFF at IFM RangeRLA LRA FullNOM IFM No P.E Combustion PowerFAN Motor Exhaust Type DISC. SizeNOM 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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