Contents

Owners Information Manual
- A170030
- Fig. 1 Unit 48VL
  - Safety Considerations
  - Unit Introduction
    - Starting or Shutting Off Unit
      - 1. Set the temperature selector on room thermostat to the lowest temperature setting and set system switch to HEAT.
      - 2. Close the external manual gas shutoff valve.
      - 3. Turn off the electrical supply to the unit.
      - 4. Remove the control access panel with a 5/16-in. nut driver. (See Fig. 2.)
      - Fig. 2 Unit Access Panel
        
        5. Move the selector switch on the internal gas valve to the OFF position and wait 5 minutes.
        
        6. Move the selector switch on the internal gas valve to the ON position.
        
        7. Replace the control access panel.
        
        8. Turn on the electrical supply to unit.
        
        9. Open the external manual gas shutoff valve.
        
        10. Set the temperature selector on room thermostat slightly above room temperature to start unit. The induced-draft combustion air fan will start. Main gas valve will open and main burners should ignite within 5 seconds. If the burner does not light...
        
        11. Set the temperature selector on room thermostat to desired setting.
        
        1. If the main burners fail to light, or the blower fails to start, shut down gas heating section and call your dealer for service.
        
        2. Never attempt to manually light the main burners on unit with a match, lighter, or any other flame. If the electric sparking device fails to light the main burners, refer to the following shutdown procedures, then call your dealer as soon as possible
      - Fig. 3 Gas Heating/Electric Cooling Unit with Access Panel Removed
    - To shut off unit gas heat:
      - 1. Set the temperature selector on room thermostat to lowest temperature setting and set system SWITCH to OFF.
      - 2. Close the external manual shutoff valve.
      - 3. Turn off the electrical power supply to the unit.
      - 4. Remove the control access panel. (See Fig. 2.)
      - 5. Move the selector switch on the internal gas valve to the OFF position.
      - 6. Replace the control access panel.
    - To start unit electric cooling:
      - 1. Set the temperature selector on room thermostat to highest temperature setting and set system SWITCH to OFF.
      - 2. Close the external manual shutoff valve, if not already closed.
      - 3. Turn ON the electrical power supply to the unit.
      - 4. Set system switch to COOL.
      - 5. Set the temperature selector on room thermostat slightly below the room temperature to start unit.
    - To shut off unit electric cooling:
      - 1. Set the temperature selector on room thermostat to highest temperature setting and set system SWITCH to OFF.
      - 2. Close the external manual shutoff valve, if not already closed.
      - 3. Turn off the electrical power supply to the unit.
  - Operating Your Unit
    - Cooling Mode
    - Gas Heat Mode
  - Maintenance and Service
    - Routine Maintenance
  - A07662
- Fig. 4 To Start Unit Gas Heat
  - A07663
- Fig. 5 To Shut-off Unit Gas Heat
  - A09194
- Fig. 6 To Start Unit Electric Cooling
  - A07797
- Fig. 7 To Shut-off Unit Electric Cooling
  - Maintenance and Care for the Equipment Owner
    - 1. Turn off gas supply first, then all electrical power to your unit and install lock-out tag before servicing or performing maintenance.
    - 2. When removing access panels or performing maintenance functions inside your unit, be aware of sharp sheet metal parts and screws. Although special care is taken to reduce sharp edges to a minimum, be extremely careful when handling parts or reachi...
  - Air Filters
    - 1. Remove the filter access panel using a 5/16-in. nut driver.
    - 2. Remove the filter(s) by pulling it out of the unit. If the filter(s) is dirty, clean or replace with a new one.
    - 3. Reinstall filter access panel ensuring opening is air and water tight.
    - Table 1 Replacement Filter Sizes
  - Replacing or inspecting filters in units with economizers
    - 1. Remove return air duct cover at rear of unit using a 5/16-in. nut driver.
    - 2. Remove the filter(s) by pulling it out and through the unit duct opening. If filter is dirty, replace both filters with new ones.
    - 3. Reinstall duct cover ensuring opening is air and watertight.
    - 1. Remove filter access door using a 5/16-in. nut driver.
    - 2. Remove the filter(s) by pulling it out and through the unit filter access door. If filter is dirty, replace both filters with new ones.
    - 3. Reinstall filter access door ensuring opening is air and water tight.
    - Fig. 8 Small Chassis Filter Access
    - Fig. 9 Large Chassis Filter Access
  - Fans and Fan Motors
  - Heat Exchanger
  - Indoor and Outdoor Coils
  - Condensate Drain
  - Compressor
  - Condenser (Outdoor) Fan
  - Electrical Controls and Wiring
  - Refrigerant Circuit
  - Unit Panels
  - Combustion Area and Vent System
  - Regular Dealer Maintenance (Also refer to Table 2)
    - 1. Inspection of all flue product passages-including the burners, heat exchanger, and flue collector box, Mare sure the burner flames are blue in color and in proper adjustment. Refer to Fig. 10 for burner flame.
    - 2. Inspection of all combustion-and ventilation-air passages and openings.
    - 3. Close inspection of all gas pipes leading to and inside of your unit.
    - 4. Inspection and, if required, cleaning of the outdoor and indoor coils.
    - 5. Inspection and, if required, cleaning of the indoor coil condensate drain pan.
    - Fig. 10 Monoport Burner
      - 6. Inspection and cleaning of blower wheel housing and motor.
      - 7. Inspection of all supply-air and return-air ducts for leaks, obstructions, and insulation integrity. Any problems found should be resolved at this time.
      - 8. Inspection of the unit base to ensure that no cracks, gaps, etc., exist which may cause a hazardous condition.
      - 9. Inspection of the unit casing for signs of deterioration.
      - 10. Inspection of all electrical wiring and components to assure proper connection.
      - 11. Inspection for leaks in the refrigerant circuit. Pressure check to determine appropriate refrigerant charge.
      - 12. Operational check of the unit to determine working conditions. Repair or adjustment should be made at this time.
  - Warranty Certificate
  - Before you call for service...
  - In Case of Trouble
    - Table 2 Maintenance Checklist

Carrier 48VL Owner's Manual

Pages 10

Year 2020

Language(s)

of 10

Carrier 48VL Specification

The Carrier 48VL is a versatile rooftop unit designed for commercial applications, providing efficient heating, cooling, and ventilation solutions. It integrates advanced technology with robust engineering to deliver optimal performance and energy efficiency. The unit is available in various capacities, allowing it to cater to different building sizes and requirements.

The 48VL features a high-efficiency scroll compressor that ensures reliable operation and reduced energy consumption. It is equipped with a multi-speed ECM motor, which offers improved airflow control and enhances the unit's overall efficiency. The use of a dual-fuel capability allows for seamless switching between gas and electric heating, optimizing energy use based on the prevailing conditions.

This rooftop unit boasts a durable construction, with a corrosion-resistant casing that ensures longevity and withstands harsh environmental conditions. It includes an advanced control system that provides precise temperature management and easy integration with building management systems. The Carrier 48VL also supports optional accessories such as economizers and CO2 sensors, which further enhance its energy-saving capabilities.

The unit is designed for easy installation and maintenance, featuring hinged access panels and simplified electrical connections. Its compact footprint allows for flexible placement on rooftops, making it suitable for various architectural layouts. With adherence to stringent industry standards, the Carrier 48VL ensures compliance with energy efficiency regulations and environmental guidelines, making it an ideal choice for sustainable building projects.

Carrier 48VL F.A.Q.

How do I reset the Carrier 48VL unit after a power outage?

To reset your Carrier 48VL unit after a power outage, turn off the thermostat, then turn off the power to the unit at the main breaker. Wait approximately 5 minutes before turning the power back on and resetting the thermostat to your desired settings.

What should I do if the Carrier 48VL is not heating properly?

First, check the thermostat settings and ensure they are correct. Inspect the air filters and replace them if they are dirty. If the problem persists, examine the pilot light or ignition system for issues or contact a professional technician.

How often should I perform maintenance on the Carrier 48VL unit?

It is recommended to perform maintenance on your Carrier 48VL unit twice a year, ideally in spring and fall. This includes cleaning or replacing air filters, inspecting ductwork, and checking refrigerant levels.

What are the common error codes for Carrier 48VL and what do they mean?

Common error codes include E1 (communication fault), E2 (indoor coil freeze protection), and E3 (outdoor unit fault). Refer to the user manual for a comprehensive list and specific troubleshooting steps.

How do I improve the energy efficiency of my Carrier 48VL unit?

Ensure regular maintenance is performed, including cleaning filters and coils. Seal any leaks in ductwork and consider upgrading to a programmable thermostat to optimize energy use.

Why is my Carrier 48VL unit making unusual noises?

Unusual noises may indicate loose components, debris in the blower, or issues with the fan motor. Inspect the unit for visible issues and tighten any loose parts. If the noise persists, contact a professional technician.

Can I install the Carrier 48VL unit myself?

Installation of the Carrier 48VL unit should be performed by a qualified HVAC professional to ensure safety, proper setup, and to maintain warranty validity.

What should I do if the Carrier 48VL is leaking water?

Check the condensate drain line for clogs and ensure it is properly connected. If the issue persists, inspect the evaporator coil for ice build-up, which may indicate a refrigerant issue. Contact a professional if needed.

How can I switch my Carrier 48VL from cooling to heating mode?

To switch modes, adjust the thermostat settings from 'cool' to 'heat'. If the unit does not respond, check the thermostat manual for specific instructions or reset the system as needed.

What maintenance tasks can I perform myself on the Carrier 48VL?

Homeowners can regularly replace or clean air filters, check the thermostat settings, and visually inspect the unit for any obvious signs of wear or damage. Always turn off power before performing maintenance.