Carrier 48HJD005-007 specifications Contents, Safety Considerations, Installation, Step

48HJD005-007, 48HJE/HJF004-007 48HJL/HJM/HJN/HJG/HJH/HJK004-006 (LOW NOx)

Single-Package Rooftop Heating/Cooling

Installation, Start-Up and

Service Instructions

CONTENTS

Page

SAFETY CONSIDERATIONS . . . . . . . . . . . . . . . . . . . . . . 1 INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-28 Step 1 — Provide Unit Support . . . . . . . . . . . . . . . . . . . 1

•ROOF CURB

•SLAB MOUNT

Step 2 — Field Fabricate Ductwork		3
Step 3 — Install External Trap for
Condensate Drain		3
Step 4	— Rig and Place Unit	3
• POSITIONING
Step 5	— Install Flue Hood	4
Step 6	— Install Gas Piping	4
Step 7	— Make Electrical Connections	4

•FIELD POWER SUPPLY

•FIELD CONTROL WIRING

•HEAT ANTICIPATOR SETTINGS

Step 8 — Adjust Factory-Installed Options . . . . . . . 8

•MOISTUREMISER DEHUMIDIFCATION PACKAGE

•APOLLO CONTROL

•DISCONNECT SWITCH

•OPTIONAL DURABLADE ECONOMIZER

•OPTIONAL ECONOMI$ER

Step 9 — Adjust Evaporator-Fan Speed . . . . . . . . . 19

• BELT-DRIVE MOTORS

PRE-START-UP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 START-UP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29-32 SERVICE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33-38 TROUBLESHOOTING. . . . . . . . . . . . . . . . . . . . . . . . . 39-45 START-UP CHECKLIST . . . . . . . . . . . . . . . . . . . . . . . . CL-1

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 install, repair, or service air-conditioning equipment.

Untrained personnel can perform basic maintenance func- tions of cleaning coils and filters and replacing filters. All other operations should be performed by trained service personnel. When working on air-conditioning equipment, observe precau- tions 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 and install lockout tag. Ensure electrical service to rooftop unit agrees with voltage and amperage listed on the unit rating plate. Elec- trical shock could cause personal injury.

Disconnect gas piping from unit when leak testing at pressure greater than 1/2 psig. Pres- sures greater than 1/2 psig will cause gas valve damage resulting in hazardous condition. If gas valve is subjected to pressure greater than 1/2 psig, it must be replaced before use. When pressure testing field-supplied gas piping at pressures of 1/2 psig or less, a unit connected to such piping must be isolated by manually closing the gas valve(s).

INSTALLATION

Unit is shipped in the vertical discharge configuration. To convert to horizontal discharge application, remove duct open- ing covers. Using the same screws, install covers on duct open- ings in basepan of unit with insulation-side down. Seals around openings must be tight.

NOTE: Any combination of supply and return ducting is per- missible, i.e., vertical supply combined with horizontal return.

Step 1 — Provide Unit Support

ROOF CURB — Assemble and install accessory roof curb in accordance with instructions shipped with curb. See Fig. 1. In- stall insulation, cant strips, roofing felt, and counter flashing as shown. Ductwork must be attached to curb, not to the unit. If electric control power or gas service is to be routed through the basepan, attach the accessory thru-the-bottom service con- nections to the basepan in accordance with the accessory instal- lation instructions. Connections must be installed before unit is set on roof curb.

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

Curb should be level. Unit leveling tolerances are shown in Fig. 2. This is necessary for unit drain to function properly. Re- fer to Accessory Roof Curb Installation Instructions for addi- tional information as required.

SLAB MOUNT (Horizontal Units Only) — Provide a level concrete slab that extends a minimum of 6 in. beyond unit cab- inet. Install a gravel apron in front of condenser-coil air inlet to prevent grass and foliage from obstructing airflow.

NOTE: Horizontal units may be installed on a roof curb if required.

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

Book	1	4	PC 111	Catalog No. 534-767	Printed in U.S.A.	Form 48HJ-18SI	Pg 1	9-00	Replaces: 48HJ-17SI
Tab	1a	6a