Bryant 542J Series Installation, Start-Up And Service Instructions Manual page 12

F. Outdoor-Air Hood Installation
The outdoor-air hood is common to 25% air ventilation and
economizer. If economizer is used, all electrical connections
have been made and adjusted at the factory. Assemble and
install hood in the field.
NOTE: The hood top panel, upper and lower filter retainers,
hood drain pan, and filter support bracket are secured oppo-
site the outdoor air end of the unit. The screens, hood side
panels, remaining section of filter support bracket, seal strip,
and all other hardware are in a package located inside the
return-air filter access panel (Fig. 19).
1. Attach seal strip to upper filter retainer. See Fig. 20.
2. Assemble hood top and side panels, upper filter re-
tainer, and drain pan (see Fig. 21).
3. Secure lower filter retainer and longer section of filter
support bracket to unit. See Fig. 21. Tighten screws.
4. Loosen sheet metal screws for base unit top panel
located above outdoor-air inlet opening, and remove screws
for hood side panels located on the sides of the outdoor-
air inlet opening.
Fig. 18 — Economizer Motor Control Module Location
Fig. 19 — Outdoor-Air Hood Component Location
Fig. 20 — Seal Strip Location
HOOD TOP
PANEL
NOTE: The outdoor-air hood kit contains a baffle which is not used on
the 542J units. Discard the baffle.
Fig. 21 — Outdoor-Air Hood Details
5. Match notches in hood top panel to unit top panel screws.
Insert hood flange between top panel flange and unit.
Tighten screws.
6. Hold hood side panel flanges flat against unit, and in-
stall screws removed in Step 4.
7. Insert outdoor-air inlet screens and spacer in channel
created by lower filter retainer and filter support bracket.
8. Attach remaining shorter section of filter support bracket.
G. Defrost Cycle
The defrost timer is factory set at 30 minutes. The timer may
be field-adjusted to 50 or 90 minutes by moving the wire from
the 30 minute contact to the 50 or 90 minute contact. At the
end of the time period, the defrost cycle will begin. See
Fig. 22.
—12—
LOWER FILTER
RETAINER
FILTER SUPPORT
BRACKET
HOOD SIDE
PANELS (2)
LOWER
FILTER
RETAINER
FILTER SUPPORT
BRACKET
HOOD DRAIN PAN
UPPER FILTER RETAINER