Carrier Installation and Specifications for 48TJD and 48TJE Rooftop Units

48TJE,TJF004 48TJD,TJE,TJF005-007 Single-Package Rooftop Heating/Cooling Units

Installation, Start-Up and

Service Instructions

CONTENTS

Page

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

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

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

•ROOF CURB

•SLAB MOUNT

Step 2 — Field Fabricate Ductwork . . . . . . . . . . . . . . . 2

Step 3 — Install External Trap for

Condensate Drain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Step 4 — Rig and Place Unit . . . . . . . . . . . . . . . . . . . . . 2

• POSITIONING
Step 5	— Install Flue Hood	4
Step 6	— Install Gas Piping	4
Step 7	— Make Electrical Connections	5

•DISCONNECT BOX LOCATION

•FIELD POWER SUPPLY

•FIELD CONTROL WIRING

•HEAT ANTICIPATOR SETTINGS

Step 8 — Make Outdoor-Air Adjustment and

Install Outdoor-Air Hood . . . . . . . . . . . . . . . . . . . . . . 12

•MANUAL OUTDOOR-AIR DAMPER

•OPTIONAL DURABLADE ECONOMIZER

•OPTIONAL ECONOMI$ER

Step 9 — Adjust Evaporator-Fan Speed . . . . . . . . . 20

•DIRECT-DRIVE MOTORS

•BELT-DRIVE MOTORS

START-UP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37-39 SERVICE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40-44 TROUBLESHOOTING. . . . . . . . . . . . . . . . . . . . . . . . . 45-50 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 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.

Ensure voltage listed on unit data plate agrees with electri- cal supply provided for the unit.

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 clos- ing the gas valve.

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

INSTALLATION

Unit is shipped in the vertical discharge configuration. To convert to horizontal configuration, remove screws from side duct opening covers and remove covers. Using the same screws, install covers on vertical duct openings with the insula- tion side down. Seals around duct openings must be tight. See Fig. 1.

Step 1 — Provide Unit Support

ROOF CURB — Assemble and install accessory roof curb in accordance with instructions shipped with curb. See Fig. 2. In- stall insulation, cant strips, roofing felt, and counter flashing as shown. Ductwork must be attached to curb, not to the unit. The accessory thru-the-bottom power and gas connection package must be installed before the unit is set on the roof curb. If field- installed (thru-the-roof curb) gas connections are desired, use factory-supplied 3/4 in. pipe coupling and gas plate assembly to mount the thru-the-roof curb connection to the roof curb. Gas connections and power connections to the unit must be field in- stalled after the unit is installed on the roof curb.

If electric and control wiring is to be routed through the basepan, attach the accessory thru-the-bottom service connec- tions to the basepan in accordance with the accessory installa- tion instructions.

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. 2. Improperly applied gasket can also result in air or water leaks and poor unit performance.

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. 534-774	Printed in U.S.A.	Form 48TJ-18SI	Pg 1	10-00	Replaces: 48TJ-16SI
Tab	1a	6a