Carrier 48/50HJ004-014 specifications Contents, Safety Considerations, General

COBRA™ Energy Recovery Units 48/50HJ004-014 with 62AQ060-300 Single-Package Rooftop Units with Energy Recovery Capability

Installation, Start-Up,

and Service Supplement

IMPORTANT: This is a supplemental instruction for the 48/50HJ and the 62AQ Installation, Start-Up and Service Instructions. It is not intended to take the place of either instruction or to be a complete piece in itself.

CONTENTS

Page SAFETY CONSIDERATIONS . . . . . . . . . . . . . . . . . . . . . . 1 GENERAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-29 Step 1 — Inspect Shipment . . . . . . . . . . . . . . . . . . . . . . 2 Step 2 — Provide Unit Support . . . . . . . . . . . . . . . . . . . 2

• ROOF CURB

Step 3 — Field Fabricate Ductwork . . . . . . . . . . . . . . . 3 Step 4 — Rig and Place Unit . . . . . . . . . . . . . . . . . . . . . 6

•POSITIONING

Step 5 — Install Flue Hood (48HJ Only) . . . . . . . . . 11 Step 6 — Install Gas Piping (48HJ Only). . . . . . . . . 11

Step 7 — Install External Trap for Condensate Drain. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Step 8 — Make Electrical Connections . . . . . . . . . . 11

•FIELD POWER SUPPLY

•FACTORY-SUPPLIED NON-FUSED DISCONNECT

•FIELD CONTROL WIRING

•HEAT ANTICIPATOR SETTINGS

Step 9 — Assemble and Mount

Supply-Air Hood . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 Step 10 — Mount the Barometric Relief Damper . . 28

Step 11 — Set the Outdoor Cooling and

Heating Thermostats. . . . . . . . . . . . . . . . . . . . . . . . . . 29

LIGHT COMMERCIAL THERMIDISTAT ACCESSORY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30-34

General. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Dehumidification Equipment and Connections . . . 30

Step 1 — Select Light Commercial

Thermidistat Location . . . . . . . . . . . . . . . . . . . . . . . . . 30

Step 2 — Set DIP Switches . . . . . . . . . . . . . . . . . . . . . . . 30

Step 3 — Install Light Commercial Thermidistat . . 31

Step 4 — Set Light Commercial Thermidistat

Configuration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Step 5 — Conduct Light Commercial

Thermidistat Start-Up and Checkout . . . . . . . . . . . 33

Step 6 — Make Final Settings . . . . . . . . . . . . . . . . . . . . 34

OPERATIONAL INFORMATION . . . . . . . . . . . . . . . . . . 34

PRE-START-UP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 START-UP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 SERVICE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35-37 TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . 38-41

ROOFTOP UNIT AND ENERGY$RECYCLER2 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 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.

Verify that the power source supplied to the unit matches the voltages and amperages listed on the unit rating plate.

Follow all safety codes. Wear safety glasses and work gloves. Use quenching cloth for unbrazing operations. Have fire extinguishers available for all brazing operations.

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 condi- tion. 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.

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

GENERAL

Carrier’s factory-installed optional COBRA Energy Recov- ery units precondition ventilation air for the rooftop unit during winter and summer operation and recover energy from the building exhaust air. These units are designed to satisfy the higher ventilation requirements and other building codes while minimizing energy costs.

Factory installation of the energy recovery section provides the benefit of reduced field-installation time, single point pow- er connections, and the assurance of a factory test for the com- plete COBRA Energy Recovery unit. The energy recovery sec- tion requires less maintenance than other energy recovery systems and can be serviced by any qualified refrigeration technician.

NOTE: Because of the location of the energy recovery section, the unit nameplate has been moved to the opposite end of the rooftop section, on the upper, right-hand part of the panel.

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

Book	1	1	4	4	PC 111 Catalog No. 534-80122	Printed in U.S.A.	Form 48/50HJ,62AQ-2SIS	Pg 1	9-02	Replaces: 48/50HJ,62AQ-1SIS
Tab	1a	1b	6a	6b