Carrier 48TCA04---A12 appendix Supply FAN Blower Section, Supply Fan Belt-Drive

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C07156

 

Fig. 4 - Screens Installed on Outdoor-Air Hood

 

(Sizes 7-1/2 to 12-1/2 Tons Shown)

48TC

To remove the screen, loosen the screws in the top retainer

 

 

and slip the retainer up until the filter can be removed.

 

Re-install by placing the frame in its track, rotating the

 

retainer back down and tighten all screws.

 

SUPPLY FAN (BLOWER) SECTION

! WARNING

ELECTRICAL SHOCK HAZARD

Failure to follow this warning could cause personal injury or death.

Before performing service or maintenance operations on the fan system, shut off all unit power and tag-out the unit disconnect switch. Do not reach into the fan section with power still applied to unit.

Supply Fan (Belt-Drive)

The supply fan system consists of a forward-curved centrifugal blower wheel on a solid shaft with two concentric type bearings, one on each side of the blower housing. A fixed-pitch driven pulley is attached to the fan shaft and an adjustable-pitch driver pulley is on the motor. The pulleys are connected using a “V” type belt. (See Fig. 5.)

C07087

Fig. 5 - Belt Drive Motor Mounting

Belt

Check the belt condition and tension quarterly. Inspect the belt for signs of cracking, fraying or glazing along the

inside surfaces. Check belt tension by using a spring-force tool (such as Browning’s Part Number “Belt Tension Checker” or equivalent tool); tension should be 6-lbs at a 5/8-in. deflection when measured at the centerline of the belt span. This point is at the center of the belt when measuring the distance between the motor shaft and the blower shaft.

NOTE: Without the spring-tension tool, place a straight edge across the belt surface at the pulleys, then deflect the belt at mid-span using one finger to a 1/2-in. deflection.

Adjust belt tension by loosening the motor mounting plate front bolts and rear bolt and sliding the plate toward the fan (to reduce tension) or away from fan (to increase tension). Ensure the blower shaft and the motor shaft are parallel to each other (pulleys aligned). Tighten all bolts when finished.

To replace the belt:

1.Use a belt with same section type or similar size. Do not substitute a “FHP” type belt. When installing the new belt, do not use a tool (screwdriver or pry-bar) to force the belt over the pulley flanges, this will stress the belt and cause a reduction in belt life.

2.Loosen the motor mounting plate front bolts and rear bolts.

3.Push the motor and its mounting plate towards the blower housing as close as possible to reduce the cen- ter distance between fan shaft and motor shaft.

4.Remove the belt by gently lifting the old belt over one of the pulleys.

5.Install the new belt by gently sliding the belt over both pulleys and then sliding the motor and plate away from the fan housing until proper tension is achieved.

6.Check the alignment of the pulleys, adjust if neces- sary.

7.Tighten all bolts.

8.Check the tension after a few hours of runtime and re-adjust as required.

Adjustable-Pitch Pulley on Motor

The motor pulley is an adjustable-pitch type that allows a servicer to implement changes in the fan wheel speed to match as-installed ductwork systems. The pulley consists of a fixed flange side that faces the motor (secured to the motor shaft) and a movable flange side that can be rotated around the fixed flange side that increases or reduces the pitch diameter of this driver pulley. (See Fig. 6.)

As the pitch diameter is changed by adjusting the position of the movable flange, the centerline on this pulley shifts laterally (along the motor shaft). This creates a requirement for a realignment of the pulleys after any adjustment of the movable flange. Also reset the belt tension after each realignment.

Check the condition of the motor pulley for signs of wear. Glazing of the belt contact surfaces and erosion on these surfaces are signs of improper belt tension and/or belt slippage. Pulley replacement may be necessary.

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Contents Table of Contents Safety ConsiderationsUnit Arrangement and Access Routine MaintenanceGeneral What to do if you smell gasSeasonal Maintenance Supply FAN Blower Section Supply Fan Belt-DriveCooling Condenser Coil Maintenance and Cleaning RecommendationCondenser Coil Periodic Clean Water Rinse Routine Cleaning of Coil SurfacesRemove Surface Loaded Fibers One-Row CoilRefrigerant System Pressure Access Ports Cleaning the Evaporator CoilEvaporator Coil Evaporator Coil Metering DevicesTo Use Cooling Charging Charts Puronr R-410A RefrigerantRefrigerant Charge No ChargeCooling Charging Charts Size Designation Nominal Tons ReferenceCooling Charging Charts C08229 C08437 C08438 C08439 Cooling Service Analysis Problem Cause RemedyCondenser-Fan Adjustment Troubleshooting Cooling SystemConvenience Outlets CompressorSmoke Detectors SystemController Unit Connect Primary TransformerSensor Smoke Detector LocationsCompleting Installation of Return Air Smoke Sensor Fiop Smoke Detector Wiring and ResponseSensor Alarm Test Sensor Alarm Test ProcedureController Alarm Test Sensor and Controller TestsController Alarm Test Procedure Dirty Controller Test ProcedureDirty Sensor Test Procedure To Configure the Dirty Sensor Test OperationDetector Cleaning Troubleshooting Protective Devices GAS Heating SystemCompressor Protection Relief DeviceFuel Types and Pressures Natural Gas Supply Line Pressure RangesNatural Gas Manifold Pressure Ranges Liquid Propane Supply Line Pressure RangesFlue Gas Passageways Combustion-Air BlowerCleaning and Adjustment Check Unit Operation and Make Necessary Adjust- mentsBurners and Igniters Main BurnersLimit Switch Burner IgnitionLED Error Code Description Orifice ReplacementLED Indication Error Code Description Red LED-Status IGC Connections Orifice SizesCont. Altitude Compensation* A08-A12 Altitude Compensation* A04-A07LP Orifice Minimum heating entering air temperature Troubleshooting Heating SystemAltitude Compensation* A04-A06 Low NOx Units 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 Recommended Cables RTU-MP Control SystemColor Code Recommendations 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 Power Exhaust output Connecting Discrete InputsCommunication Wiring Protocols RTU-MP Troubleshooting LEDs LEDs on the RTU-MP show the status of certain functionsTroubleshooting Alarms Alarms BACnet MS/TPRTU-MP Driver Basic Protocol Troubleshooting ModbusManufacture Date Code Name MeaningEconomizer Systems EconoMi$er IV Component LocationsEconoMi$er IV Wiring EconoMi$er EconoMi$er IV Input/Output LogicSupply Air Temperature SAT Sensor Outdoor Air Lockout SensorEconoMi$er IV Control Modes Outdoor Dry Bulb ChangeoverReturn Air Temperature or Enthalpy Sensor Mounting Location Outdoor Enthalpy ChangeoverIndoor Air Quality IAQ Sensor Input Exhaust Setpoint AdjustmentMinimum Position Control Damper Movement ThermostatsOccupancy Control Demand Control Ventilation DCVCO2 Sensor Configuration EconoMi$er IV Sensor UsageEconoMi$er IV Preparation Differential EnthalpyWiring Diagrams 48TC Typical Unit Wiring Diagram Power A06, 208/230-3-60 48TC Unit Wiring Diagram Control A06 PRE-START-UP START-UP, GeneralCooling Main BurnersHeating Ventilation Continuous FanField Service Test START-UP, Premierlink ControlsSTART-UP, RTU-MP Control Perform System Check-OutConfiguration Inputs InputSpace Sensor Type Input 1 FunctionOperating Sequences Base Unit Controls Cooling, Units Without EconomizerHeating, Units Without Economizer Cooling, Unit With EconoMi$erHeating With EconoMi$er PremierLink Control48TC Available Cooling Stages OAT ≤ SPT 48TC 48TC Loadshed Command Gas and Electric Heat Units RTU-MP Sequence of OperationLinkage Modes SchedulingAlways Occupied Default Occupancy Local ScheduleBACnet Schedule BAS On/OffEconomizer Power ExhaustIndoor Air Quality Demand Limit Fastener Torque ValuesTorque Values Appendix I. Model Number Significance Model Number NomenclatureSerial Number Format 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 NotesTon Vertical Supply Ton Horizontal SupplyCFM RPM BHP Medium Static Option High Static Option 48TC**05 Phase Ton Horizontal Supply 48TC**0548TC**05 Phase Ton Vertical Supply 14931506 148648TC**06 148248TC**06 Phase Ton Horizontal Supply 48TC**06 Phase Ton Vertical SupplyPhase Ton Horizontal Supply 48TC**071107 11241103 1143 1122 1162497 10991116 1093 1133579 12631247 1273Pulley Adjustment Unit MOTOR/DRIVE Motor Pulley Turns Open ComboAppendix IV. Electrical Data IFMRange RLA LRA TypeAppendix IV. Electrical Data FLAIFM Range EFF atRLA LRA FullCombustion Power NOM IFM No P.EFAN Motor Exhaust 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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