III. STEP 3 — FIELD FABRICATE DUCTWORK

Secure all ducts to building structure. Use flexible duct con- nectors between unit and ducts as required. Insulate and weatherproof all external ductwork, joints, and roof openings with counter flashing and mastic in accordance with applica- ble codes.

Ducts passing through an unconditioned space must be insu- lated and covered with a vapor barrier.

The 551A units with electric heat require a 1-in. clearance for the first 24 in. of ductwork.

Outlet grilles must not lie directly below unit discharge.

NOTE: A 90-degree elbow must be provided in the ductwork to comply with UL (Underwriters’ Laboratories) codes for use with electric heat.

WARNING: For vertical supply and return units, tools or parts could drop into ductwork and cause an injury. Install a 90 degree turn in the return ductwork between the unit and the conditioned space. If a 90 degree elbow cannot be installed, then a grille of sufficient strength and density should be installed to prevent objects from falling into the conditioned space. Due to electric heater, supply duct will require 90 degree elbow.

IV. STEP 4 — MAKE UNIT DUCT CONNECTIONS

Unit is shipped for thru-the-bottom duct connections. Duct- work openings are shown in Fig. 6. Field-fabricated concen- tric ductwork may be connected as shown in Fig. 7 and 8. Attach all ductwork to roof curb and roof curb basepans. Refer to installation instructions shipped with accessory roof curb for more information.

V. STEP 5 — TRAP CONDENSATE DRAIN

See Fig. 4, 5, and 9 for drain location. Plug is provided in drain hole and must be removed when unit is operating. One 3/4-in. half-coupling is provided inside unit evaporator sec- tion for condensate drain connection. An 81/2 in. x 3/4-in. diameter nipple and a 2-in. x 3/4-in. diameter pipe nipple are coupled to standard 3/4-in. diameter elbows to provide a straight path down through holes in unit base rails (see Fig. 10). A trap at least 4-in. deep must be used.

NOTE: Do not drill in this area, as damage to basepan may result in water leak.

Fig. 6 — Air Distribution — Thru-the-Bottom

(551A180 and 240 Shown)

NOTE: Do not drill in this area, as damage to basepan may result in water leak.

Shaded area indicates block-off panels.

NOTE: Dimension A, Aand B, Bare obtained from field-supplied ceil- ing diffuser.

CAUTION: Concentric ducts may only be installed on units without electric heat. Personal injury or unit damage may result.

Fig. 8 — Concentric Duct Details

INDOOR FAN MOTOR ACCESS

FILTER

ACCESS

3/4" FPT DRAIN

1-3/8"

CONNECTION

DRAIN HOLE

Fig. 7 — Concentric Duct Air Distribution

Fig. 9 — Condensate Drain Details

(551A180 and 240 Shown)

(551A155 Shown)

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Bryant 551A operation manual III. Field Fabricate Ductwork, IV. Make Unit Duct Connections, Trap Condensate Drain