Inspection

Prior to initial use, and at monthly intervals, all rigging shackles, clevis pins, and straps should be visually inspected for any damage, evidence of wear, structural deformation, or cracks. Particular attention should be paid to excessive wear at hoist hooking points and load support areas. Materials showing any kind of wear in these areas must not be used and should be discarded.

!WARNING

UNIT FALLING HAZARD

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

Never stand beneath rigged units or lift over people.

!WARNING

PROPERTY DAMAGE HAZARD

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

When straps are taut, the clevis should be a minimum of 36 in. (914 mm) above the unit top cover.

Rigging/Lifting of Unit (See Fig. 5)

Lifting holes are provided in base rails as shown in Fig. 2 and 3.

1.Leave top shipping skid on the unit for use as a spreader bar to prevent the rigging straps from damaging the unit. If the skid is not available, use a spreader bar of sufficient length to protect the unit from damage.

2.Attach shackles, clevis pins, and straps to the base rails of the unit. Be sure materials are rated to hold the weight of the unit (See Fig. 5).

3.Attach a clevis of sufficient strength in the middle of the straps. Adjust the clevis location to ensure unit is lifted level with the ground.

After the unit is placed on the roof curb or mounting pad, remove the top skid.

Step 6 — Connect Condensate Drain

NOTE: When installing condensate drain connection be sure to comply with local codes and restrictions.

Model 48EZ-A disposes of condensate water through a 3/4 in. NPT fitting which exits through the compressor access panel (See Fig. 2 and 3 for location).

Condensate water can be drained directly onto the roof in rooftop installations (where permitted) or onto a gravel apron in ground level installations. Install a field-supplied condensate trap at end of condensate connection to ensure proper drainage. Make sure that the outlet of the trap is at least 1 in. (25 mm) lower than the drain-pan condensate connection to prevent the pan from overflowing (See Fig. 6). Prime the trap with water. When using a gravel apron, make sure it slopes away from the unit.

If the installation requires draining the condensate water away from the unit, install a 2-in. (51 mm) trap at the condensate connection to ensure proper drainage (See Fig. 6). Make sure that the outlet of the trap is at least 1 in. (25 mm) lower than the drain-pan condensate connection. This prevents the pan from overflowing.

Prime the trap with water. Connect a drain tube - using a minimum of 3/4-in. PVC or 3/4-in. copper pipe (all field-supplied) - at the outlet end of the 2-in. (51 mm) trap. Do not undersize the tube. Pitch the drain tube downward at a slope of at least 1-in. (25 mm) for every 10 ft (3 m) of horizontal run. Be sure to check the drain tube for leaks.

TRAP

OUTLET

1-in. (25 mm) min.

2-in. (51 mm) min.

A09052

Fig. 6 - Condensate Trap

Step 7 — Install Flue Hood

The flue assembly is secured and shipped in the return air duct. Remove duct cover to locate the assembly (See Fig. 8 and 9).

NOTE: Dedicated low NOx models MUST be installed in California Air Quality Management Districts where a Low NOx rule exists.

These models meet the California maximum oxides of nitrogen (NOx) emissions requirements of 40 nanograms/joule or less as shipped from the factory.

NOTE: Low NOx requirements apply only to natural gas installations.

!WARNING

CARBON MONOXIDE POISONING HAZARD

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

The venting system is designed to ensure proper venting. The flue hood assembly must be installed as indicted in this section of the unit installation instructions.

Install the flue hood as follows:

1.This installation must conform with local building codes and with the National Fuel Gas Code (NFGC) NFPA 54 / ANSI Z223.1, (in Canada, CAN/CGA B149.1, and B149.2) latest revision. Refer to Provincial and local plumbing or wastewater codes and other applicable local codes.

2.Remove flue hood from shipping location (inside the return section of the blower compartment-see Fig. 8 & 9). Re- move the return duct cover to locate the flue hood. Place flue hood assembly over flue panel. Orient screw holes in flue hood with holes in the flue panel.

3.Secure flue hood to flue panel by inserting a single screw on the top flange and the bottom flange of the hood.

Step 8 — Install Gas Piping

The gas supply pipe enters the unit through the access hole provided. The gas connection to the unit is made to the 1/2-in. (12.7 mm) FPT gas inlet on the gas valve.

Install a gas supply line that runs to the heating section. Refer to Table 2 and the NFGC for gas pipe sizing. Do not use cast-iron pipe. It is recommended that a black iron pipe is used. Check the local utility for recommendations concerning existing lines. Size gas supply piping for 0.5 IN. W.C. maximum pressure drop. Never use pipe smaller than the 1/2-in. (12.7 mm) FPT gas inlet on the unit gas valve.

For natural gas applications, the gas pressure at unit gas connection must not be less than 4.0 IN. W.C. or greater than 13 IN. W.C. while the unit is operating. For propane applications, the gas pressure must not be less than 11.0 IN. W.C. or greater than 13 IN. W.C. at the unit connection.

48EZ -- A

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Carrier 48EZ-A installation instructions Connect Condensate Drain, Install Flue Hood, Install Gas Piping, Inspection

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.