48EZ -- A

Servicing Systems on Roofs and with Synthetic materials

POE (polyolester) compressor lubricants are known to cause long term damage to some synthetic roofing materials.

Exposure, even if immediately cleaned up, may cause embrittlement (leading to cracking) to occur in one year or more. When performing any service that may risk exposure of compressor oil to the roof, take appropriate precautions to protect roofing. Procedures which risk oil leakage include, but are not limited to, compressor replacement, repairing refrigerant leaks, replacing refrigerant components such as filter drier, pressure switch, metering device, coil, accumulator, or reversing valve.

Synthetic Roof Precautionary Procedure

1.Cover extended roof working area with an impermeable polyethylene (plastic) drip cloth or tarp. Cover an approximate 10x10 ft (3x3 m) area.

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

3.Place terry cloth shop towel inside unit immediately under component(s) to be serviced and prevent lubricant run-offs through the louvered openings in the unit base.

4.Perform required service.

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

Liquid Line Filter Drier

This filter drier is specifically designed to operate with Puron. Use only factory-authorized components. Filter drier must be replaced whenever the refrigerant system is opened. When removing a filter drier, use a tubing cutter to cut the drier from the system. Do not unsweat a filter drier from the system. Heat from unsweating will release moisture and contaminants from drier into system.

Puron (R-410A) Refrigerant Charging

Refer to unit information plate and charging chart. Some R-410A refrigerant cylinders contain a dip tube to allow liquid refrigerant to flow from cylinder in upright position. For cylinders equipped with a dip tube, charge Puron units with cylinder in upright position and a commercial metering device in manifold hose. Charge refrigerant into suction-line.

TROUBLESHOOTING

Use the Troubleshooting Guides (See Tables 10-12) if problems occur with these units.

START-UP CHECKLIST

Use Start-Up checklist to ensure proper start-up procedures are followed.

PURONR (R-410A) QUICK REFERENCE GUIDE

SPuron refrigerant operates at 50-70 percent higher pressures than R-22. Be sure that servicing equipment and replacement components are designed to operate with Puron

SPuron refrigerant cylinders are rose colored.

SRecovery cylinder service pressure rating must be 400 psig, DOT 4BA400 or DOT BW400.

SPuron systems should be charged with liquid refrigerant. Use a commercial type metering device in the manifold hose when charging into suction line with compressor operating

SManifold sets should be minimum 700 psig high side and 180 psig low side with 550 psig low-side retard. S Use hoses with minimum 700 psig service pressure rating.

S Leak detectors should be designed to detect HFC refrigerant. S Puron, as with other HFCs, is only compatible with POE oils. S Vacuum pumps will not remove moisture from oil.

S Do not use liquid-line filter driers with rated working pressures less than 600 psig. S Do not leave Puron suction line filter driers in line longer than 72 hrs.

S Do not install a suction-line filter drier in liquid line.

S POE oils absorb moisture rapidly. Do not expose oil to atmosphere. S POE oils may cause damage to certain plastics and roofing materials. S Wrap all filter driers and service valves with wet cloth when brazing. S A factory approved liquid-line filter drier is required on every unit.

S Do NOT use an R-22 TXV.

S Never open system to atmosphere while it is under a vacuum.

S When system must be opened for service, recover refrigerant, evacuate then break vacuum with dry nitrogen and replace filter driers. Evacuate to 500 microns prior to recharging.

S Do not vent Puron into the atmosphere.

S Observe all warnings, cautions, and bold text.

S All indoor coils must be installed with a hard shutoff Puron TXV metering device.

34

Page 33 Page 35
Page 34
Image 34
Carrier 48EZ-A installation instructions Troubleshooting, START-UP Checklist, Puronr R-410A Quick Reference Guide
Page 33 Page 35

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.
Top Page Image Contents