Carrier 48EY024-068, 48EW specifications Contents, Safety Considerations, Make Outdoor-AirInlet

48AJ,AK,AW,AY020-060 with Reciprocating Compressor 48EJ,EK,EW,EY024-068 Single Package Rooftop Units Electric Cooling/Gas Heating

Installation, Start-Up and

Service Instructions

CONTENTS

Page

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

INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-58

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 . . . . . . . . . . . . . . . . . . . . . . 28 Step 6 — Trap Condensate Drain . . . . . . . . . . . . . . . . 28 Step 7 — Install Gas Piping . . . . . . . . . . . . . . . . . . . . . 28 Step 8 — Controls Options . . . . . . . . . . . . . . . . . . . . . . 29

•STAGED GAS UNIT APPLICATIONS

•THERMISTORS

•CONSTANT VOLUME APPLICATIONS

•VARIABLE AIR VOLUME (VAV) APPLICATIONS

Step 9 — Make Electrical Connections . . . . . . . . . . 33

•POWER WIRING

•FIELD POWER SUPPLY

•FIELD CONTROL WIRING

Step 10 — Make Outdoor-Air Inlet

Adjustments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

•ECONOMIZER

•ECONOMIZER SETTINGS

Step 11 — Position Power Exhaust/Barometric

Relief Damper Hood. . . . . . . . . . . . . . . . . . . . . . . . . . . 52

Step 12 — Install All Accessories . . . . . . . . . . . . . . . 54

Step 13 — Field Modifications. . . . . . . . . . . . . . . . . . . 57

START-UP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58-89 SERVICE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89-102 TROUBLESHOOTING. . . . . . . . . . . . . . . . . . . . . . . 103-115 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 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.

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, 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.

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

1.All panels must be in place when rigging.

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.

Book	1	PC 111	Catalog No. 534-739	Printed in U.S.A.	Form 48A,E-1SI	Pg 1	107	11-01	Replaces: 48E-6SI
Tab	1a