Carrier 48EZ-A Outdoor Fan, Electrical Controls and Wiring, Refrigerant Circuit

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48EZ -- A

BLOWER

HOUSING

2 SETSCREWS

(HIDDEN)

C99085

Fig. 20 - Removal of Motor and Blower Wheel

A07680

Fig. 21 - Burner Rack Removed

FEEDER TUBE

STUB TUBE

DEFROST

THERMOSTAT

C99029

Fig. 22 - Defrost Thermostat Location

A07680

Fig. 23 - Burner Rack Removed

Outdoor Fan

!CAUTION

UNIT OPERATION HAZARD

Failure to follow this caution may result in damage to unit components.

Keep the outdoor fan free from all obstructions to ensure proper cooling operation. Never place articles on top of the unit.

1.Remove 6 screws holding outdoor grille and motor to top cover.

2.Turn motor/grille assembly upside down on top cover to expose the fan blade.

3.Inspect the fan blades for cracks or bends.

4.If fan needs to be removed, loosen the setscrew and slide the fan off the motor shaft.

5.When replacing fan blade, position blade back to the same position as before.

6.Ensure that setscrew engages the flat area on the motor shaft when tightening.

7.Replace grille.

Electrical Controls and Wiring

Inspect and check the electrical controls and wiring annually. Be sure to turn off the gas supply, and then the electrical power to the unit.

Remove access panels (see Fig. 19) to locate all the electrical controls and wiring. Check all electrical connections for tightness. Tighten all screw connections. If any discolored or burned connections are noticed, disassemble the connection, clean all the parts, re-strip the wire end and reassemble the connection properly and securely.

After inspecting the electrical controls and wiring, replace the access panels (see Fig. 19). Start the unit, and observe at least one complete heating cycle and one complete cooling cycle to ensure proper operation. If discrepancies are observed in any operating cycle, or if a suspected malfunction has occurred, check each electrical component with the proper electrical instrumentation. Refer to the unit wiring label when making these checkouts.

NOTE: Refer to the heating and/or cooling sequence of operation in this publication as an aid in determining proper control operation.

Refrigerant Circuit

Annually inspect all refrigerant tubing connections and the unit base for oil accumulations. Detecting oil generally indicates a refrigerant leak.

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Contents Table of Contents Safety ConsiderationsCheck Equipment Receiving and InstallationIntroduction Provide Unit Support48EZ-A24-36 Unit Dimensions 48EZ-A42-60 Unit Dimensions Small Curb Personal Injury or Property Damage Rig and Place UnitProvide Clearances HazardConnect Condensate Drain Install Flue HoodInstall Gas Piping InspectionFire or Explosion Hazard Sediment TrapPhysical Data Unit 48EZ-A Unit Size 48EZPhysical Data Unit 48EZ-A Cont’d Maximum Gas Flow CapacityHeating Inputs Alternate Method Install Duct ConnectionsConfiguring Units for Downflow Vertical Discharge Unit Component Damage HazardSupply Duct Panels High-Voltage Connections Install Electrical ConnectionsSpecial Procedures for 208-V Operation Control Voltage ConnectionsTransformer Protection Balance Point Setting-Thermidistat or Hybrid ThermostatPRE-START-UP FIRE, EXPLOSION, Electrical Shock HazardCheck for Refrigerant Leaks Start-up Heating and Make Adjust- mentsSTART-UP Unit Sequence of OperationCheck Gas Input Adjust Gas InputCheck Heating Control Unit Damage HazardRollout Switch Airflow and Temperature RiseLimit Switches Check Burner FlameIndoor Airflow and Airflow Adjustments Start-up Cooling and Make Adjust- mentsChecking and Adjusting Refrigerant Charge Checking Cooling Control OperationContinuous Fan Operation Two Cooling Fan Speeds Set-up Dehumidification feature usedGas Heating Fan Speed Set-up Color Coding for Indoor Fan Motor LeadsFilter Pressure Drop Table IN. W.C 48EZ-A Wet Coil Pressure Drop IN. W.C741 638 547 415 Heating Low Blue 1234 1168 1093 1021 961 894 825 759 687 Heating Low Blue 1736 1695 1642 1601 1553 1512 1465 1427 1381 65oF Heating 1927 1893 1858 1824 1791 1759 1720 1689 1640 65oF Heating 48EZ a 208/230-3-60 Wiring Diagram, Unit 48EZ-A Cooling Charging Table-Subcooling Air Filter MaintenanceCleaning the Blower Motor and Wheel Indoor Blower and MotorBurner Ignition Limit SwitchInduced Draft combustion air Blower Assembly Main BurnersElectrical Controls and Wiring Outdoor FanRefrigerant Circuit Gas Input Pressure SwitchesLoss of Charge Switch Indoor AirflowHigh-Pressure Switch Copeland Scroll Compressor Puron RefrigerantExplosion Hazard Unit Operation and Safety Hazard Refrigerant SystemCompressor Oil Troubleshooting START-UP ChecklistPuronr R-410A Quick Reference Guide Troubleshooting Guide Cooling or Heat Pump Heating Mode Symptom Cause RemedyTroubleshooting Guide-Heating Troubleshooting Guide-LED Error CodesPreliminary Information Model no TemperaturesRemove and Store in Job Files III. START-UP Electrical Supply Voltage Compressor AmpsCatalog No 48EZ---06SI
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48EZ-A specifications

The Carrier 48EZ-A and 48VT-A are two advanced rooftop unit air conditioners that exemplify innovation and efficiency in HVAC technology. Designed for commercial applications, these units provide optimal comfort while ensuring energy conservation and reliability.

One of the standout features of the Carrier 48EZ-A is its high-efficiency cooling system. With SEER ratings reaching up to 16, this model uses advanced compressor technology to ensure that energy consumption stays low while maximizing cooling output. The 48EZ-A incorporates a two-stage scroll compressor that enhances performance during partial load conditions, making it ideal for varying temperature demands throughout the day.

Meanwhile, the Carrier 48VT-A is designed with variable speed technology that allows for precise modulation of airflow and cooling capacity, adapting seamlessly to real-time building conditions. This technology not only improves comfort but also significantly reduces energy usage by optimizing operational efficiency.

Both units are equipped with advanced microprocessor controls that facilitate superior management of the HVAC system. The controls offer programmable options allowing for enhanced control over system operation, scheduling, and diagnostics. This promotes easy maintenance and ensures long-term reliability.

In terms of construction, the Carrier 48EZ-A and 48VT-A units are built with corrosion-resistant materials, ensuring durability and longevity even in challenging environments. The cabinet is designed with insulated panels to minimize sound levels, making them suitable for installation in noise-sensitive locations.

Moreover, both models are equipped for easy installation and serviceability. The logical wiring design and access ports streamline maintenance, reducing downtime and optimizing overall performance. Additionally, they feature an energy-efficient fan design that maximizes airflow while minimizing energy use.

In summary, the Carrier 48EZ-A and 48VT-A rooftop units stand out in the HVAC market for their energy efficiency, advanced technology, and durable construction. These features make them ideal choices for various commercial applications where comfort, efficiency, and reliability are paramount. The combination of high-performance components and user-friendly features positions these models as leaders in modern HVAC solutions.
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