Determine Type of Unit Control

48PD, 48PG

Always keep the unit’s area clear of combustible materials. Do not obstruct the air openings to the unit. Air is required for combustion and ventilation proper operation. Follow the instruction provided in this book for lighting and shutting down the unit. Should the gas supply fail to shut off or if overheating occurs, shut off the gas valve to the unit before shutting off the electrical supply. The following inspections must be completed post unit installation. The detailed routine maintenance inspections are in the Maintaining Your Unit section.

Post Unit Installation Inspection:

1.All flue and vent connections are clear and free of obstructions, are leak free, and not damaged.

2.Duct connections are leak free and physically sound.

3.The unit base support is free of cracks, gaps, etc.

4.There are no signs of furnace deterioration.

5.Burners are aligned correctly.

6.Follow routine maintenance inspection.

!WARNING

FIRE, EXPLOSION HAZARD

Failure to follow this warning could result in personal injury and/or death.

Improper installation, adjustment, alteration, service or maintenance can cause injury or property damage. Refer to this manual. For assistance or additional information, consult a qualified installer, service agency or the gas supplier.

!WARNING

FIRE, EXPLOSION HAZARD

Failure to follow this warning could result in personal injury, death and/or property damage.

Burners will light automatically. Do not attempt to light by hand.

Your combination heating/cooling unit is equipped with direct spark ignition and induced draft power combustion blower.

!WARNING

FIRE, EXPLOSION HAZARD

Failure to follow this warning could result in personal injury, death and/or property damage.

Burners will light automatically. Do not attempt to light by hand.

!WARNING

ELECTRICAL OPERATION HAZARD

Failure to follow this warning could result in personal injury, death and/or property damage.

Do not use this unit if any part has been under water. A flood-damaged unit is extremely dangerous. Attempts to use the unit can result in fire or explosion. A qualified service agency should be contacted to inspect the unit and replace any parts that have been wet or the unit, if deemed necessary.

The procedures used to light or shut off the unit depend on the type of unit control. This section will help determine the control type of the unit.

Electro-Mechanical Control

These units may be controlled directly by a thermostat, or indirectly by a third-party control that connects to the thermostat inputs. For direct thermostat control, use the Electro-Mechanical Control procedures in this book. For units with third-party controls connected to the thermostat inputs, refer to the third-party control instructions for procedures to ensure complete unit shut off.

ComfortLinkt Control

These units have a factoryinstalled Carrier ComfortLink control. A Scrolling Marquee display is located on the front of the unit control box behind the control box and compressor access door. These units may be controlled directly by a thermostat, directly by a space temperature sensor, or indirectly through other Carrier Comfort Networkr (CCN) communication devices. To ensure complete unit shut off, use the ComfortLink Control procedures in this book.

TO LIGHT UNIT

(UNITS WITH ELECTRO-MECHANICAL

CONTROL)

!DANGER

FIRE, EXPLOSION HAZARD

Failure to follow this warning could result in personal injury or death.

1.Do not turn off the electrical power to unit without first turning off the gas supply and applying lockout tags.

2.Before attempting to start the gas heating section, familiarize yourself with all the procedures that must be followed.

3.Never attempt to manually light the burners on the unit with a match, lighter, or any other flame. If the electric sparking device fails to light the burners, refer to the shutdown procedures, then call your dealer as soon as possible.

See Fig. 1. for location of gas valve. Refer to Fig. 2 while proceeding with the following steps:

Step 1 — Set room thermostat to the lowest temperature setting and set SYSTEM switch to OFF position.

Step 2 — Close the shutoff valve on the gas supply piping. Step 3 — Turn off the electrical supply to the unit and install lockout tag.

Step 4 — Open the heat section access panel.

Step 5 — Move ON/OFF switch on the internal main gas valve to the OFF position an

Step 6 — Move ON/OFF switch on internal main gas valve to ON position.

Step 7 — Close the heat section access panel.

Step 8 — Remove lockout tag and turn on the electrical supply to unit.

Step 9 — Open the shutoff valve on the external gas supply piping.

48PD05, 06 specifications

The Carrier 48PD05 and 48PD06 are highly efficient packaged rooftop units designed specifically for commercial applications. They are known for their reliability, advanced technologies, and exceptional performance in diverse weather conditions. Both units leverage Carrier's decades of experience in HVAC technology to deliver optimal indoor comfort with minimal energy consumption.

One of the standout features of the 48PD series is their advanced cooling capabilities. These units utilize scroll compressors, which are renowned for their efficiency and quiet operation. This results in reduced noise levels, making them suitable for a variety of commercial environments, including restaurants, offices, and retail spaces. The units also come equipped with multiple cooling capacities, allowing for precise matching to the specific thermal requirements of the building.

Energy efficiency is a key characteristic of the 48PD05 and 48PD06. Both units feature high SEER (Seasonal Energy Efficiency Ratio) ratings, ensuring that they consume less electricity while delivering superior cooling performance. The use of microchannel coil technology further enhances efficiency. This innovation reduces refrigerant charge requirements and improves heat transfer, allowing the units to operate effectively in various climatic conditions.

In addition to cooling, these units also provide heating functionality, making them an all-in-one solution for year-round climate control. They incorporate electric heating elements as well as optional gas heat capabilities, providing flexibility based on user preference and fuel availability. This versatility ensures that facilities can maintain comfort regardless of seasonal changes.

The Carrier 48PD series is also designed with ease of installation and maintenance in mind. The compact rooftop design allows for straightforward placement on a building’s roof, reducing installation costs and time. Furthermore, serviceability is enhanced through features like removable access panels, which provide easy access to critical components.

Safety and reliability are paramount in Carrier's design philosophy. Both units include a variety of safety features such as high-pressure and low-pressure switches, ensuring the longevity and protection of the system. Additionally, the intelligent controls available with the 48PD models facilitate precise temperature management, enhancing occupant comfort while optimizing energy use.

In conclusion, the Carrier 48PD05 and 48PD06 packaged rooftop units stand out due to their efficient cooling and heating capabilities, innovative technologies, and user-friendly design. Their combination of performance, energy efficiency, and advanced features makes them a reliable choice for commercial heating and cooling needs, assuring users of comfort and cost-effectiveness throughout their operation.