Carrier 48TCA04---A12 appendix Available Cooling Stages

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48TC

SIf the PremierLink controller is in the occupied mode and ASHRAE 90.1 Supply Fan is configured for Yes when Linkage is active and the Linkage Coordinator device is sending an occupied mode flag

S When Temperature Compensated Start is active S When Free Cool is active

SWhen Pre-Occupancy Purge is active

SWhenever there is a demand for cooling or heating in the unoccupied mode

S Whenever the Remote Contact input is configured for Remote Contact (RC_DC=1 in SERVICE table) and it is closed or the point is forced Closed via communications in the STATUS01 points display table (remote contact closed = occupied, remote contact open = unoccupied)

S Whenever the H3_EX_RV point is configured for Dehumidification (AUXOUT=5 in CONFIG table) and it is in the unoccupied mode and the indoor RH exceeds the unoccupied humidity setpoint

SWhenever the Supply Fan Relay point is forced On in the STATUS01 points display table

The fan will also continue to run as long as compressors are on when transitioning from occupied to unoccupied with the exception of Fire Shutdown mode. If the Fire Shutdown input point is closed or forced in the STATUS01 points display table, the fan will be shutdown immediately regardless of the occupancy state or demand.

The PremierLink controller has an optional Supply Fan Status input to provide proof of airflow. If this is enabled, the point will look for a contact closure whenever the Supply Fan Relay is on. If the input is not enabled, then it will always be the same state as the Supply Fan Relay. The cooling, economizer and heating routines will use this input point for fan status.

Cooling — The compressors are controlled by the Cooling Control Loop that is used to calculate the desired SAT needed to satisfy the space. It will compare the SPT to the Occupied Cool Setpoint (OCSP) + the T56 slider offset (STO) when occupied and the Unoccupied Cool Setpoint (UCSP + Unoccupied Cooling Deadband) if unoccupied to calculate a Cooling Submaster Reference (CCSR) that is then used by the staging algorithm (Cooling submaster loop) to calculate the required number of cooling stages. The economizer, if available, will be used as the first stage of cooling in addition to the compressors. This loop runs every minute. The following conditions must be met in order for this algorithm to run:

S indoor fan has been ON for at least 30 seconds

S heat mode is not active and the time guard between modes equals zero.

S mode is occupied or the Temperature Compensated Start or Cool mode is active

S SPT reading is available and > (OCSP + STO)

S If mode is unoccupied and the SPT > (UCSP + Unoccupied Cooling Deadband). The indoor fan will be turned on by the staging algorithm.

S OAT > DXLOCK or OAT DX Lockout is disabled

If all of the above conditions are met, the CCSR will be calculated, otherwise it is set to its maximum value and DX stages is set to 0. If only the last condition is not true and an economizer is available, it will be used to cool the space.

The submaster loop uses the CCSR compared to the actual SAT to determine the required number of capacity stages to satisfy the load. There is a programmable minimum internal time delay of 3 to 5 minutes on and 2 to 5 minutes off for the compressors to prevent short cycling. There is also a 3-minute time delay before bringing on the second stage compressor. If the PremierLink controller is configured for Heat Pump and AUXOUT is configured for Reversing Valve Cool, the H3_EX_RV output will energize 2 seconds after the first compressor is energized and stay energized until there is a demand for heat. If AUXOUT is configured for Reversing Valve Heat, then the H3_EX_RV contact will be deenergized when there is

ademand for cooling. An internal 5 to 10-minute user-programmable time guard between modes prevents rapid cycling between modes when used in a single zone application. The Time Guard is lowered to 3 minutes when Linkage is active to allow the 3Vt linkage coordinator to have better control of the PremierLink controller when used as the air source for the 3V control system.

Table 29 indicates the number of stages available. The staging algorithm looks at the number of stages available based the number of cool stages configured in the SERVICE configuration table. The algorithm will skip the economizer if it is not available and turn on a compressor.

Table 29 – Available Cooling Stages

NUMBER OF

0

1

2

3

STAGES

(ECONOMIZER*)

 

 

 

 

 

 

 

 

Compressor 1

Off

Off

On

On

Compressor 2

Off

Off

Off

On

* If conditions are suitable for economizer operation.

Any time the compressors are running, the PremierLink controller will lockout the compressors if the SAT becomes too low. These user configurable settings are found in the SERVICE configuration table:

Compressor 1 Lockout at SAT < SATLO1 (50 to 65_F) (default is 55_F)

Compressor 2 Lockout at SAT < SATLO2 (45 to 55_F) (default is 50_F)

After a compressor is locked out, it may be started again after a normal time-guard period and the supply air temperature has increased at least 8_F above the lockout setpoint.

Dehumidification — The PremierLink controller will provide occupied and unoccupied dehumidification control when AUXOUT = 5 in the CONFIG table and is installed on HVAC units that are equipped with additional controls and accessories to accomplish this function. This function also requires a space relative humidity sensor be installed on the OAQ/IRH input.

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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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