Carrier SINGLE PACKAGE ROOFTOP UNITS 48PG20-28 Installation And Service Instructions Manual

Also see for 48PG20---28: User's information manual User's information manual Controls, start-up, operation, service and troubleshooting instructions

Carrier SINGLE PACKAGE ROOFTOP UNITS 48PG20-28 Installation And Service Instructions Manual 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.PC 111 Catalog No. 534-80211 Printed in U.S.A. Form 48PG-10SI Pg 1 9-05 Replaces: NewBook 1 4Tab 1a 6aInstallation, Start-Up and Service InstructionsCONTENTSPageSAFETY CONSIDERATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . 1,2INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-17Step 1 — Provide Unit Support . . . . . . . . . . . . . . . . . . . . . . . . .2• ROOF CURB• ALTERNATE UNIT SUPPORT• SLAB MOUNTStep 2 — Remove Shipping Rails . . . . . . . . . . . . . . . . . . . . . . .2Step 3 — Rig and Place Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . .2• POSITIONING• ROOF MOUNT• INSTALLATION ONTO CURBStep 4 — Field Fabricate Ductwork . . . . . . . . . . . . . . . . . . . . .9Step 5 — Make Unit Duct Connections. . . . . . . . . . . . . . . . . .9• VERTICAL CONFIGURATION• HORIZONTAL APPLICATIONSStep 6 — Install Flue Hood and Inlet Hood . . . . . . . . . . . . 10Step 7 — Trap Condensate Drain . . . . . . . . . . . . . . . . . . . . . 10Step 8 — Install Gas Piping . . . . . . . . . . . . . . . . . . . . . . . . . . . 10Step 9 — Make Electrical Connections. . . . . . . . . . . . . . . . .11• FIELD POWER SUPPLY• FIELD CONTROL WIRINGStep 10 — Install Outdoor-Air Hood. . . . . . . . . . . . . . . . . . . 12• MANUAL DAMPER ASSEMBLYStep 11 — Position Optional PowerExhaust or Barometric Relief Damper Hood . . . . . . . . . 16Step 12 — Non-Fused Disconnect . . . . . . . . . . . . . . . . . . . . 16Step 13 — Install All Accessories . . . . . . . . . . . . . . . . . . . . . 16PRE-START-UP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18START-UP. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18-45Unit Preparation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18Compressor Mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18Refrigerant Service Ports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18Crankcase Heater(s) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18Compressor Rotation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18Internal Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18Subcooler Heat Exchanger (SHX) . . . . . . . . . . . . . . . . . . . . . 18Evaporator Fan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18Condenser Fans and Motors. . . . . . . . . . . . . . . . . . . . . . . . . . 19Return-Air Filters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19Outdoor-Air Inlet Screens. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19Gas Heat. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19Optional EconoMi$er IV. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39Operating Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44SERVICE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .46-57Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46Lubrication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47Manual Outdoor Air Damper . . . . . . . . . . . . . . . . . . . . . . . . . . 48Economizer Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48Evaporator Fan Service and Replacement . . . . . . . . . . . . 48Evaporator Fan Performance Adjustment . . . . . . . . . . . . . 48Evaporator Fan Belt Tension Adjustment . . . . . . . . . . . . . 48Condenser Fan Adjustment. . . . . . . . . . . . . . . . . . . . . . . . . . . 49Verify Sensor Performance . . . . . . . . . . . . . . . . . . . . . . . . . . . 49Economizer Operation During Power Failure. . . . . . . . . . 49Evacuation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49Refrigerant Charge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50Gas Valve Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50High Altitude. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51Main Burners . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51Filter Drier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52Protective Devices. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52Relief Devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52PageControl Circuit, 24-V . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52Replacement Parts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52Diagnostic LEDs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57-61Unit Troubleshooting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57EconoMi$er IV Troubleshooting. . . . . . . . . . . . . . . . . . . . . . . 60Phase Loss Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61UNIT START-UP CHECKLIST . . . . . . . . . . . . . . . . . . . . . . . . CL-1SAFETY CONSIDERATIONSInstallation and servicing of air-conditioning equipment canbe hazardous due to system pressure and electrical compo-nents. Only trained and qualified service personnel shouldinstall, repair, or service air-conditioning equipment.Untrained personnel can perform the basic maintenancefunctions of cleaning coils and filters and replacing filters. Allother operations should be performed by trained service per-sonnel. When working on air-conditioning equipment, observeprecautions 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 workgloves. Use quenching cloth for unbrazing operations. Havefire extinguishers available for all brazing operations.Before performing service or maintenance operations onunit, turn off main power switch to unit. Electrical shockcould cause personal injury.Puron (R-410A) refrigerant systems operate at higher pres-sures than standard R-22 systems. Do not use R-22 serviceequipment or components on Puron refrigerant equipment.If service equipment is not rated for Puron refrigerant,equipment damage or personal injury may result.1. Improper installation, adjustment, alteration, service,or maintenance can cause property damage, personalinjury, or loss of life. Refer to the User’s InformationManual provided with this unit for more details.2. Do not store or use gasoline or other flammablevapors and liquids in the vicinity of this or any otherappliance.What to do if you smell gas:1. DO NOT try to light any appliance.2. DO NOT touch any electrical switch, or use anyphone 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 firedepartment.48PG20-28Single Package Rooftop UnitsElectric Cooling/Gas Heating withElectromechanical Controls and PURON® (R-410A) Refrigerant