Carrier SINGLE PACKAGE ROOFTOP 48HC Installation Instructions Manual

Also see for 48TC*D: Service and maintenance instructions Installation instructions

15Positioning on Curb —Position unit on roof curb so that the following clearancesare maintained: 1 / 4 in. (6 mm) clearance between the roofcurb and the base rail inside the right and left, 1 / 2 in.(12 mm) clearance between the roof curb and the base railinside the front and back. This will result in the distancebetween the roof curb and the base rail inside on thecondenser end of the unit being approximately equal toDetails A and B in Figs. 6, 7 and 8.Do not attempt to slide unit on curb after unit is set. Doingso will result in damage to the roof curb seal.Although unit is weatherproof, guard against water fromhigher level runoff and overhangs.Flue vent discharge must have a minimum horizontalclearance of 48 in. (1220 mm) from electric and gas meters,gas regulators, and gas relief equipment. Minimum distancebetween unit and other electrically live parts is 48 inches(1220 mm).Flue gas can deteriorate building materials. Orient unit suchthat flue gas will not affect building materials. Locatemechanical draft system flue assembly at least 48 in. (1220mm) from an adjacent building or combustible material.After unit is in position, remove rigging skids andshipping materials.Step 7 — Horizontal Duct ConnectionRefer to Figs. 1, 2 and 3 for locations and sizes of thehorizontal duct connections. Note that there are two differentreturn air duct connection locations – one for unit without aneconomizer (on back side of unit) and a different one forunit equipped with an economizer (on left end, under theeconomizer hood). The supply air duct connection is on theback side. See Fig. 11 for top view depicting typicalhorizontal duct arrangements.Return Air Ductwith EconomizerReturn Air DuctwithoutEconomizerHorizontalSupply AirC10626Supply Return withoutEconomizerReturn withEconomizerLocation Back Back Left endHeight --- In. (mm) 157/8 (402) 493 / 8 (1253) 183 / 8 (467)Width --- in. (mm) 293/4 (756) 233 / 8 (593) 615 / 8 (1564)Fig. 11 -- Horizontal Duct Opening DimensionsField--supplied (3/4--inch) flanges should be attached tohorizontal duct openings (see Fig. 11) and all ductworkshould be secured to the flanges. Insulate and weatherproofall external ductwork, joints, and roof or building openingswith counter flashing and mastic in accordance withapplicable codes.Step 8 — Install Outside Air Hood — FactoryOptionThe outside air hood for factory--option economizer andtwo--position damper is shipped in knock--down form andrequires field assembly. The panel for the hood top isshipped on the end of the unit (see Fig. 12). Theremaining parts for the hood assembly (including sidepanels, filters and tracks) are shipped in a carton that issecured to the rear of the blower assembly. Access thecarton location through rear panel (see Fig. 13).Hood TopShippingPositionC09134Fig. 12 -- Hood Top – Shipping PositionTo remove the hood parts package:1. Remove the back blower access panel.2. Locate and cut the strap, being careful to not damageany wiring.3. Carefully lift the hood package carton through theback blower access opening.See Fig. 14 for identification of the various parts of thehood assembly.HoodPackageC09133Fig. 13 -- Hood Package – Shipping Location48HC