Bryant Durapac Plus Series 551a User Manual

Page 7

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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.

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

-in. half-coupling is provided inside unit evaporator sec-

tion for condensate drain connection. An 8

in. x

-in.

diameter nipple and a 2-in. x

-in. diameter pipe nipple are

coupled to standard

-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.

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.

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.

Fig. 7 — Concentric Duct Air Distribution

(551A180 and 240 Shown)

3/4" FPT DRAIN
CONNECTION

1-3/8"
DRAIN HOLE

INDOOR FAN MOTOR ACCESS

FILTER
ACCESS

Shaded area indicates block-off panels.

NOTE: Dimension A, A

′ and B, B′ are obtained from field-supplied ceil-

ing diffuser.

Fig. 8 — Concentric Duct Details

CAUTION:

Concentric ducts may only be installed on

units without electric heat. Personal injury or unit damage may
result.

Fig. 9 — Condensate Drain Details

(551A155 Shown)