48/50PD

To inspect blower wheel, open heat section door. Using a flashlight, look into the flue exhaust duct to inspect. If cleaning is required, remove motor and wheel assembly by removing the screws holding the flue box cover to the flue box. Remove the screws holding the inducer housing to the inlet plate. The wheel can then be removed from the motor shaft and cleaned with a detergent or solvent. Replace the wheel onto the motor shaft in the correct position and reassemble the flue cover onto the flue box.

Lubrication

Compressors

Each compressor is charged with the correct amount of oil at the factory.

!CAUTION

UNIT DAMAGE HAZARD

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

The compressor is in a Puron refrigerant system and uses a polyolester (POE) oil. This oil is extremely hygroscopic, meaning it absorbs water readily. POE oils can absorb 15 times as much water as other oils designed for HCFC and CFC refrigerants. Avoid exposure of the oil to the atmosphere.

Polyolester (POE) compressor lubricants are known to cause long term damage to some synthetic roofing materials. Exposure, even if immediately cleaned up, may cause roofing materials to become brittle (leading to cracking) within a year. When performing any service which may risk exposure of compressor oil to the roof, take appropriate precautions to protect roofing. Procedures which risk oil leakage include compressor replacement, repairing refrigerant leaks, and replacing refrigerant components. To prepare rooftop:

1.Cover extended roof work area with an impermeable plastic dropcloth or tarp. Make sure a 10 x 10 ft area around the work area is covered.

2.Cover area in front of the unit service panel with a terry cloth shop towel to absorb lubricant spills and prevent run-offs. Towel will also protect dropcloth from tears caused by tools or components.

3.Place terry cloth shop towel inside the unit directly under components to be serviced to prevent spills through the bottom of the unit.

4.Perform the required service.

5.Remove an dispose of any oil contaminated material per local codes.

Indoor Fan Shaft Bearings

The indoor fan has permanently sealed bearings. No field lubrication is necessary.

Condenser and Evaporator-Fan Motor Bearings

The condenser-fan and evaporator-fan motors have permanently sealed bearings, so no field lubrication is necessary.

Economizer or Manual Outside Air Damper

If blade adjustment is required, refer to unit or accessory installation instructions.

Evaporator Fan Service and Replacement

The units feature a slide-out fan deck for easy servicing of the indoor-fan motor, pulleys, belt, bearings and VFD. To service components in this section, perform the following procedure:

1.Turn off unit power.

2.Open the fan section access door.

3.Remove two no. 10 screws at front of slide-out fan deck. Save screws. (See Fig. 30.)

4.Disconnect the electrical wires connected to the slide-out fan deck (supply air thermistor and fan status switch if installed). Wires may be damaged if not disconnected.

5.Fan deck can now be slid out to access serviceable components.

!CAUTION

UNIT DAMAGE HAZARD

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

DO NOT SLIDE FAN DECK OUT PAST THE FAN DECK STOP. If further access is required, the fan deck must be supported. Make sure plugs and wiring are not pinched between fan housing and unit sheet metal post.

6.To replace fan deck to operating position, slide fan deck back into the unit. Secure with the two no. 10 screws removed in Step 3.

7.Re-attach electrical wires.

8.Close fan section access door.

9.Restore power to unit.

C08661

Fig. 30 - Evaporator-Fan Motor Adjustment

Evaporator Fan Performance Adjustment

Fan motor pulleys are factory set for speed shown in Appendix D. To change fan speeds:

1.Shut off unit power supply.

2.Loosen nuts on the 4 carriage bolts in the mounting base. Using adjusting bolts and plate, slide motor and remove belt.

3.Loosen movable-pulley flange setscrew. (See Fig. 31.)

4.Screw movable flange toward fixed flange to increase speed and away from fixed flange to decrease speed. Increasing fan speed increases load on motor. Do not exceed maximum speed specified in Appendix D.

See Appendix D for air quantity limits.

5.Set movable flange at nearest keyway of pulley hub and tighten setscrew. (See Appendix D for speed change for each full turn of pulley flange.)

6.Replace belts.

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Carrier 48/50PD05 manual Lubrication, Evaporator Fan Service and Replacement, Evaporator Fan Performance Adjustment
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48/50PD05 specifications

The Carrier 48/50PD05 is a remarkable addition to Carrier's lineup of rooftop units, offering advanced cooling and heating solutions for commercial applications. Designed for medium-sized buildings, this unit is well-suited for both new installations and as a replacement for older systems, thanks to its versatile features and efficient performance.

One of the standout features of the 48/50PD05 is its energy efficiency. It incorporates state-of-the-art technology to achieve high Seasonal Energy Efficiency Ratios (SEER) and EER ratings, reducing operational costs while delivering superior comfort. The unit is also compliant with the latest energy regulations, making it an environmentally friendly choice for building owners concerned about sustainability.

The 48/50PD05 is equipped with a highly efficient scroll compressor, which not only enhances performance but also contributes to quiet operation. This is a significant advantage in commercial spaces where noise levels need to be kept in check for comfort and productivity. Additionally, the unit includes advanced airflow design, ensuring even distribution of conditioned air throughout the space.

Technologically, the Carrier 48/50PD05 features Carrier's Infinity Control system, which allows for precise control of indoor climate. This intelligent control mechanism can be integrated with smart building management systems, enabling users to monitor and manage energy use effectively. Wi-Fi connectivity is also available, providing remote access for real-time adjustments and diagnostics.

Durability is another characteristic of the 48/50PD05. Constructed with high-quality materials, the unit withstands various environmental conditions, ensuring longevity and reliability. Moreover, the modular design facilitates easy maintenance, making service procedures efficient and cost-effective.

In addition to cooling, the Carrier 48/50PD05 offers heating capabilities, often utilizing gas or electric heating options that can be tailored to the specific needs of a building. The unit can also be equipped with integrated economizers, allowing for free cooling during suitable outdoor conditions, further enhancing energy savings.

Overall, the Carrier 48/50PD05 stands out as a high-performance HVAC solution that combines efficiency, technology, and durability. It provides building owners with a versatile tool to ensure comfort while minimizing their environmental footprint. With a strong emphasis on energy savings and advanced control features, this rooftop unit is a smart investment for any commercial property.
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