48EZ(N)---A

Comfortt 13 SEER Single---Packaged HYBRID HEAT

Dual Fuel System with Puronr (R---410A) Refrigerant

Single And Three Phase

2---5 Nominal Tons (Sizes 24---60)

Installation Instructions

NOTE: Read the entire instruction manual before starting the installation.

NOTE: Installer: Make sure the Owner’s Manual and Service Instructions are left with the unit after installation.

TABLE OF CONTENTS

 

 

PAGE

SAFETY CONSIDERATIONS

. 1-2

INTRODUCTION

. . . 2

RECEIVING AND INSTALLATION

2-13

Check Equipment

. . . 2

Identify Unit

. . . 2

Inspect Shipment

. . . 2

Provide Unit Support

. . . 2

Roof Curb

. . . 2

Slab Mount

. . . 2

Field Fabricate Ductwork

. . . 2

Provide Clearances

. . . 6

Rig and Place Unit

. . . 6

Connect Condensate Drain

. . . 7

Install Flue Hood

. . . 7

Install Gas Piping

. . . 7

Install Duct Connections

. . 11

Configuring Units for Downflow (Vertical)

 

Discharge

. . 11

Install Electrical Connections

. . 13

High-Voltage Connections

. . 13

Special Procedures for 208-V Operation

. . 13

Control Voltage Connections

. . 13

Balance Point Setting Thermidistat or Hybrid Heat

 

Thermostat

. . 13

Transformer Protection

. . 13

PRE-START-UP

. . 14

START-UP

15-18

Check for Refrigerant Leaks

. . 15

Unit Sequence of Operation

. . 15

Start-Up Heating and Make Adjustments

. . 15

Checking Heating Control

. . 16

Check Gas Input

. . 16

Adjust Gas Input

. . 16

Check Burner Flame

. . 17

Start-Up Cooling and Make Adjustments

. . 18

Checking Cooling Control Operation

. . 18

Checking and Adjusting Refrigerant

. . 18

Indoor Airflow and Airflow Adjustments

. . 18

MAINTENANCE

28-34

Air Filter

. . 28

Indoor Blower and Motor

. . 28

Flue Gas Passageways

. . 29

Limit Switch

. . 29

Burner Ignition

. . 29

Main Burners

. . 29

Outdoor Coil, Indoor Coil, & Condensate Drain Pan . . . .

. . 29

A09034

Fig. 1 - Unit 48EZ-A

Outdoor Fan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Electrical Controls and Wiring . . . . . . . . . . . . . . . . . . . . . . . 30

Refrigerant Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Gas Input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Indoor Airflow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Check Defrost Thermostat . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

PuronR Items . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

START-UP CHECKLIST . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

SAFETY CONSIDERATIONS

Installation and servicing of this equipment can be hazardous due to mechanical and electrical components. Only trained and qualified personnel should install, repair, or service this equipment.

Untrained personnel can perform basic maintenance functions such as cleaning and replacing air filters. All other operations must be performed by trained service personnel. When working on this equipment, observe precautions in the literature, on tags, and on labels attached to or shipped with the unit and other safety precautions that may apply.

Follow all safety codes. Wear safety glasses, protective clothing, and work gloves. Have fire extinguisher available. Read these instructions thoroughly and follow all warnings or cautions included in literature and attached to the unit. Consult local building codes, the current editions of the National Fuel Gas Code (NFGC) NFPA 54/ANSI Z223.1, and the National Electrical Code (NEC) NFPA 70.

In Canada refer to the current editions of the National Standards of Canada CAN/CSA-B149.1 and .2 Natural Gas and Propane Installation codes, and Canadian Electrical Code CSA C22.1.

Recognize safety information. This is the safety-alert symbol . When you see this symbol on the unit and in instructions or manu- als, be alert to the potential for personal injury. Understand these signal words: DANGER, WARNING, and CAUTION. These

1

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Carrier 48EZ-A installation instructions Table of Contents, Safety Considerations

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.