Installation Instructions

WEATHERMAKER® 48AJ,AK,AW,AY020-060 Single Package Rooftop Units Electric Cooling/Gas Heating with Scroll Compressor and COMFORTLINK™ Controls

Page

SAFETY CONSIDERATIONS . . . . . . . . . . . . . . . . . . . . . . 1

INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-36

Step 1 — Provide Unit Support . . . . . . . . . . . . . . . . . . . 1

•ROOF CURB

•ALTERNATE UNIT SUPPORT

Step 2 — Rig and Place Unit . . . . . . . . . . . . . . . . . . . . . 2

•POSITIONING

•ROOF MOUNT

Step 3 — Field Fabricate Ductwork . . . . . . . . . . . . . . . 2 Step 4 — Make Unit Duct Connections . . . . . . . . . . . 2 Step 5 — Install Flue Hood . . . . . . . . . . . . . . . . . . . . . . 19 Step 6 — Trap Condensate Drain . . . . . . . . . . . . . . . . 19 Step 7 — Install Gas Piping . . . . . . . . . . . . . . . . . . . . . 19 Step 8 — Make Electrical Connections . . . . . . . . . . 20

•POWER WIRING

•FIELD POWER SUPPLY

•FIELD CONTROL WIRING

Step 9 — Make Outdoor-Air Inlet

Adjustments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

•ECONOMIZER AND FIXED OUTDOOR AIR DAMPER

Step 10 — Position Power Exhaust/Barometric Relief Damper Hood. . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Step 11 — Route VAV Static Pressure Sensor . . . 34 Step 12 — Install All Accessories . . . . . . . . . . . . . . . 35 Step 13 — Field Modifications. . . . . . . . . . . . . . . . . . . 35

SAFETY CONSIDERATIONS

Installation and servicing of air-conditioning equipment can be hazardous due to system pressure and electrical compo- nents. Only trained and qualified service personnel should in- stall, repair, or service air-conditioning equipment.

Untrained personnel can perform the basic maintenance functions of cleaning coils and filters and replacing filters. All other operations should be performed by trained service per- sonnel. When working on air-conditioning equipment, observe precautions in the literature, tags and labels attached to the unit, and other safety precautions that may apply.

Follow all safety codes. Wear safety glasses and work gloves. Use quenching cloth for unbrazing operations. Have fire extinguishers available for all brazing operations.

WARNING

Before performing service or maintenance operations on unit, turn off main power switch to unit. Electrical shock could cause personal injury.

WARNING

1.Improper installation, adjustment, alteration, service, or maintenance can cause property damage, personal injury, or loss of life. Refer to the User’s Information Manual provided with this unit for more details.

2.Do not store or use gasoline or other flammable va- pors and liquids in the vicinity of this or any other appliance.

What to do if you smell gas:

1.DO NOT try to light any appliance.

2.DO NOT touch any electrical switch, or use any phone in your building.

3.IMMEDIATELY call your gas supplier from a neigh- bor’s phone. Follow the gas supplier’s instructions.

4.If you cannot reach your gas supplier, call the fire department.

WARNING

Disconnect gas piping from unit when pressure testing at pressure greater than 0.5 psig. Pressures greater than

0.5psig will cause gas valve damage resulting in hazardous condition. If gas valve is subjected to pressure greater than

0.5psig, it must be replaced before use. When pressure testing field-supplied gas piping at pressures of 0.5 psig or less, a unit connected to such piping must be isolated by closing the manual gas valve(s).

INSTALLATION

Step 1 — Provide Unit Support

CAUTION

1.All panels must be in place when rigging or damage to unit may occur.

2.Unit is not designed for handling by fork truck.

Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.

Catalog No. 04-53480067-01

Printed in U.S.A.

Form 48A-7SI

Pg 1

8-09

Replaces: 48A-5SI

48AJ specifications

The Carrier 48EJ, 48AW, 48EK, 48AJ, and 48EY024-068 are cutting-edge rooftop air conditioning units designed for commercial applications. These models are renowned for their reliability, energy efficiency, and innovative technologies aimed at providing optimal indoor comfort.

One of the standout features of these units is their advanced cooling and heating capabilities. They employ a multi-stage compressor system that allows for precise temperature control, accommodating various load requirements. This flexibility is particularly beneficial in commercial settings where the cooling load can fluctuate throughout the day.

Energy efficiency is paramount in today’s environmental landscape, and Carrier has ensured that these models meet stringent efficiency standards. They incorporate high-efficiency scroll compressors, which significantly reduce energy consumption while delivering powerful performance. The units are also equipped with variable speed fans that adjust airflow based on demand, further optimizing energy use.

In terms of construction, these rooftop units feature a robust design that enhances durability and longevity. The cabinet is constructed to withstand harsh weather conditions, ensuring reliable performance year-round. Additionally, the units are equipped with corrosion-resistant coatings, particularly useful in coastal environments where salt exposure can be a concern.

The Carrier 48EJ, 48AW, 48EK, 48AJ, and 48EY models utilize advanced controls and connectivity features, allowing for easy integration into building management systems. This connectivity enables remote monitoring and control, facilitating quick response to changing conditions and simplifying maintenance tasks.

Noise reduction is another key characteristic of these models. They are designed with sound-absorbing insulation and low-noise fan blades to ensure quiet operation, making them suitable for noise-sensitive environments such as schools and hospitals.

These units are also available with various options for air filtration and dehumidification. The use of high-efficiency air filters enhances indoor air quality by trapping dust, pollen, and other airborne particles. Enhanced dehumidification capabilities ensure that spaces remain comfortable even in humid conditions.

In conclusion, the Carrier 48EJ, 48AW, 48EK, 48AJ, and 48EY024-068 rooftop units are engineered to offer exceptional performance, energy efficiency, and durability. With their advanced technologies and user-friendly features, they stand out as reliable solutions for meeting diverse commercial cooling and heating needs, making them a popular choice for many businesses.

Carrier 48AJ installation instructions Installation Instructions

Models: 48AJ