48EJ,EK,EW,EY024-048 Single Package Rooftop Units Electric Cooling/Gas Heating

Installation, Start-Up and

Service Instructions

CONTENTS

Page

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

INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-31

Step 1 Ð Provide Unit Support . . . . . . . . . . . . . . . 1

·ROOF CURB

·ALTERNATE UNIT SUPPORT

Step 2 Ð Rig and Place Unit . . . . . . . . . . . . . . . . . . 2

·POSITIONING

·ROOF MOUNT

Step 3 Ð Field Fabricate Ductwork . . . . . . . . . . . . 2 Step 4 Ð Install Flue Hood . . . . . . . . . . . . . . . . . . 12 Step 5 Ð Trap Condensate Drain . . . . . . . . . . . . 13 Step 6 Ð Install Gas Piping . . . . . . . . . . . . . . . . . . 13 Step 7 Ð Controls Options . . . . . . . . . . . . . . . . . . 13

·CONSTANT VOLUME APPLICATIONS

·VARIABLE AIR VOLUME (VAV) APPLICATIONS

Step 8 Ð Make Electrical Connections . . . . . . . 16

·POWER WIRING

·FIELD POWER SUPPLY

·FIELD CONTROL WIRING

Step 9 Ð Make Outdoor-Air Inlet

Adjustments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

·ECONOMIZER

·ECONOMIZER SETTINGS

Step 10 Ð Position Power Exhaust/Barometric

Relief Hood . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Step 11 Ð Install All Accessories . . . . . . . . . . . . 30

START-UP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31-44 SERVICE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44-55 TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . 56-61 START-UP CHECKLIST . . . . . . . . . . . . . . . . CL-1,CL-2

SAFETY CONSIDERATIONS

Installation and servicing of air-conditioning equipment can be hazardous due to system pressure and electrical com- ponents. Only trained and quali®ed service personnel should install, repair, or service air-conditioning equipment.

Untrained personnel can perform the basic maintenance functions of cleaning coils and ®lters and replacing ®lters. All other operations should be performed by trained service personnel. When working on air-conditioning equipment, ob- serve 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 ®re ex- tinguishers available for all brazing operations.

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

1.Improper installation, adjustment, alteration, serv- ice, or maintenance can cause property damage, per- sonal 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 ¯ammable 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 ®re department.

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 haz- ardous condition. If gas valve is subjected to pressure greater than 0.5 psig, it must be replaced before use. When pressure testing ®eld-supplied gas piping at pressures of

0.5psig or less, a unit connected to such piping must be isolated by closing the manual gas valve(s).

INSTALLATION

Step 1 Ð Provide Unit Support

1.All panels must be in place when rigging.

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

ROOF CURB Ð Assemble or install accessory roof curb in accordance with instructions shipped with this accessory. See Fig. 1 and 2. Install insulation, cant strips, roo®ng, and counter ¯ashing as shown. Ductwork can be installed to roof curb before unit is set in place. Curb should be level. This is nec- essary to permit unit drain to function properly. Unit level- ing tolerance is shown in Fig. 1 and 2. Refer to Accessory Roof Curb Installation Instructions for additional informa- tion as required. When accessory roof curb is used, unit may be installed on class A, B, or C roof covering material.

IMPORTANT: The gasketing of the unit to the roof curb is critical for a watertight seal. Install gasket with the roof curb as shown in Fig. 1 and 2. Improperly applied gasket can also result in air leaks and poor unit performance.

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

Book

1

 

PC 111

Catalog No. 564-962

Printed in U.S.A.

Form 48E-5SI

Pg 1

8-97

Replaces: 48E-3SI

Tab

1a

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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Carrier EW, 48EJ, EK, EY024-048 installation instructions Installation, Start-Up Service Instructions

EW, EY024-048, EK, 48EJ 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.

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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.

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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.

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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.