Carrier WeatherExpert 48LC 14 Series Service And Maintenance Instructions

Also see for 48LC 14: Controls, Start-Up, Operation and Troubleshooting

Carrier WeatherExpert 48LC 14 Series Service And Maintenance Instructions Manual pdf 1 page image

Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.Catalog No. 04-53480153-01 Printed in U.S.A. Form 48LC-14-26-03SM Pg 1 2-2020 Replaces: 48LC-14-26-02SMService and Maintenance InstructionsCONTENTSSAFETY CONSIDERATIONS . . . . . . . . . . . . . . . . . . . . 1UNIT ARRANGEMENT AND ACCESS. . . . . . . . . . . . . 2General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2Routine Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . 3Seasonal Maintenance. . . . . . . . . . . . . . . . . . . . . . . . . 3SUPPLY FAN (BLOWER) SECTION . . . . . . . . . . . . . . 3Supply Fan (Belt-Drive) . . . . . . . . . . . . . . . . . . . . . . . . 3COOLING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5Evaporator Coil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5Refrigerant System Pressure Access Ports . . . . . . . 6Troubleshooting Cooling System. . . . . . . . . . . . . . . . 6PURON® (R-410A) REFRIGERANT. . . . . . . . . . . . . . . 8Refrigerant Charge. . . . . . . . . . . . . . . . . . . . . . . . . . . . 8COOLING CHARGING CHARTS . . . . . . . . . . . . . . . . . 9Compressors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14Filter Drier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14Condenser-Fan Adjustment . . . . . . . . . . . . . . . . . . . 14CONVENIENCE OUTLETS . . . . . . . . . . . . . . . . . . . . . 14Wet in Use Convenience Outlet Cover. . . . . . . . . . . 15Non-Powered Type. . . . . . . . . . . . . . . . . . . . . . . . . . . 15Unit-Powered Type. . . . . . . . . . . . . . . . . . . . . . . . . . . 15Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16Fuse On Powered Type . . . . . . . . . . . . . . . . . . . . . . . 16Using Unit-Mounted Convenience Outlets . . . . . . . 16SMOKE DETECTORS. . . . . . . . . . . . . . . . . . . . . . . . . 16System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16Sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16Smoke Detector Locations . . . . . . . . . . . . . . . . . . . . 17FIOP Smoke Detector Wiring and Response. . . . . . 17Sensor and Controller Tests . . . . . . . . . . . . . . . . . . . 18Detector Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . 20Indicators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20Troubleshooting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21PROTECTIVE DEVICES . . . . . . . . . . . . . . . . . . . . . . . 21Compressor Protection . . . . . . . . . . . . . . . . . . . . . . . 21Control Circuit, 24-v. . . . . . . . . . . . . . . . . . . . . . . . . . 22GAS HEATING SYSTEM . . . . . . . . . . . . . . . . . . . . . . 22General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22Fuel Types and Pressures. . . . . . . . . . . . . . . . . . . . . 22Flue Gas Passageways . . . . . . . . . . . . . . . . . . . . . . . 23Combustion-Air Blower . . . . . . . . . . . . . . . . . . . . . . . 23Burners and Ignitors . . . . . . . . . . . . . . . . . . . . . . . . . 23Burner Ignition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26Orifice Replacement . . . . . . . . . . . . . . . . . . . . . . . . . 26Minimum Heating Entering Air Temperature . . . . . . 30Troubleshooting Heating System . . . . . . . . . . . . . . . 30PRE-START-UP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32START-UP, GENERAL . . . . . . . . . . . . . . . . . . . . . . . .32Unit Preparation . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32Gas Piping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32Return-Air Filters . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32Outdoor-Air Inlet Screens . . . . . . . . . . . . . . . . . . . . .33Compressor Mounting . . . . . . . . . . . . . . . . . . . . . . . .33Internal Wiring. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33Refrigerant Service Ports. . . . . . . . . . . . . . . . . . . . . .33Compressor Rotation . . . . . . . . . . . . . . . . . . . . . . . . . 33Cooling. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33Main Burners . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33Heating. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33Ventilation (Continuous Fan). . . . . . . . . . . . . . . . . . . 33RTU Open Control System. . . . . . . . . . . . . . . . . . . . .34SystemVu™ (Factory Option) . . . . . . . . . . . . . . . . . .34Integrated Staging Control (ISC) Board . . . . . . . . . .35EconoMi$er® X (Factory Option) . . . . . . . . . . . . . . . 37Staged Air Volume (SAV™) with Variable FrequencyDrive. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .51Multi-Speed VFD Display Kit (Field-InstalledOption). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .52FASTENER TORQUE VALUES. . . . . . . . . . . . . . . . . .63SEQUENCE OF OPERATION . . . . . . . . . . . . . . . . . . .63General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .63Ventilation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .64Cooling. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .64Economizer (Optional) . . . . . . . . . . . . . . . . . . . . . . . .64Low Ambient Cooling Operation down to 40°F(4°C) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .64Heating. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .65APPENDIX A — MODEL NUMBERNOMENCLATURE . . . . . . . . . . . . . . . . . . . . . . . . . .66APPENDIX B — PHYSICAL DATA . . . . . . . . . . . . . . .67APPENDIX C — FAN PERFORMANCE . . . . . . . . . . .70APPENDIX D — WIRING DIAGRAMS . . . . . . . . . . . .81START-UP CHECKLIST . . . . . . . . . . . . . . . . . . . . .CL-1SAFETY CONSIDERATIONSInstallation and servicing of air-conditioning equipment can behazardous due to system pressure and electrical components. Onlytrained and qualified service personnel should install, repair, orservice air-conditioning equipment.Untrained personnel can perform basic maintenance functions ofcleaning coils and filters and replacing filters. All other operationsshould be performed by trained service personnel. When workingon air-conditioning equipment, observe precautions in theliterature, tags and labels attached to the unit, and other safetyprecautions that may apply.Follow all safety codes, including ANSI (American NationalStandards Institute) Z223.1. Wear safety glasses and work gloves.WeatherExpert® 48LC**14-26Single Package Rooftop Unit with Gas Heat/Electric Coolingwith Puron® (R-410A) Refrigerant