Carrier 50HJ008 Installation, Start-up And Service Instructions Manual

Also see for 50HJ008: Installation, Start-Up and Service Instructions

Contents

2Step 2 — Field Fabricate Ductwork — On verticaldischarge units, secure all ducts to roof curb and buildingstructure. Do not connect ductwork to unit. For horizontal appli-cations, field-supplied flanges should be attached to horizontaldischarge openings and all ductwork attached to the flanges. In-sulate and weatherproof all external ductwork, joints, and roofopenings with counter flashing and mastic in accordance withapplicable codes.Ducts passing through an unconditioned space must beinsulated and covered with a vapor barrier.If a plenum return is used on a vertical unit, the returnshould be ducted through the roof deck to comply with applica-ble fire codes.A minimum clearance to combustibles is not requiredaround ductwork on vertical discharge units. On horizontal dis-charge units, a minimum clearance of 1 in. is required for thefirst 12 in. of ductwork. Cabinet return-air static pressure (anegative condition) should not exceed 0.30 in. wg with econo-mizer, or 0.45 in. wg without economizer.Step 3 — Install Condensate Drain Line andExternal Trap — Condensate drain connections are locat-ed at the bottom and end of the unit. Unit discharge connec-tions do not determine the use of drain connections;either drain connection can be used in vertical or horizontalapplications.When using the standard end drain connection, make surethe plug (red) in the alternate bottom connection is tight beforeinstalling the unit.To use the bottom drain connection for a roof curb installa-tion, relocate the factory-installed plug (red) from the bottomconnection to the end connection. See Fig. 4. The piping for thecondensate drain and external trap can be completed after theunit is in place. The center drain plug looks like a star connec-tion, however it can be removed with a 1/2-in. socket driveextension.All units must have an external trap for condensate drain-age. Install a trap at least 4-in. deep and protect against freeze-up. If drain line is installed downstream from the external trap,pitch the line away from the 50HJ unit at 1 in. per 10 ft of run.Do not use a pipe size smaller than the unit connection (3/4 in.).See Fig. 5.Fig. 1 — Horizontal Conversion Panels