Carrier WEATHERMAKER 48AJ- User Manual

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

Installation Instructions

CONTENTS

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.

INSTALLATION

Step 1 — Provide Unit Support

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

0.5 psig will cause gas valve damage resulting in hazardous

condition. If gas valve is subjected to pressure greater than

0.5 psig, 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).

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.

WEATHERMAKER

®

48AJ,AK,AW,AY020-060

Single Package Rooftop Units

Electric Cooling/Gas Heating

with Scroll Compressor and

COMFORT

LINK™ Controls