Step 8 -Install Outdoor- -Air Hood; Step 9 -Position Optional Power Exhaust Or; Barometric Relief Damper Hood - Carrier 50PG20 Installation Instructions Manual

If the customer also wishes to install a smoke detector into a
Humidi-MiZert equipped 50PG unit, the fire shutdown
connection points are on Plug PL-19, located in the compressor
section outside the control box. See the unit wiring schematic for
wiring. For third- -party smoke detector, refer to Fig. 17.
Point 19-3 is the 24 vac power source for the detector, and point
19-5 is the 24 vac signal input for fire shutdown.
More information is available in the third party control section of
the Controls, Start-Up, Operation, and Troubleshooting manual.
Step 8 —Install Outdoor- -Air Hood
NOTE: On units without economizers, the components are
attached to the unit basepan. To access the components, remove the
panel below the outdoor air intake section.
Perform the following procedure to install the outdoor-air hood on
units equipped with an economizer, two-position damper, or
outdoor-air damper:
1. Remove blank panel from return end of unit (hood section).
Save the screws. See Fig. 18 for shipping location of
components.
2. Hood sides are fastened to sides of outdoor air opening.
Remove the hood sides and save the screws (3 each side).
3. Remove the bracket holding the bottom half of the hood in
the shipping position. Remove the hood bottom half and
filters (or manual dampers on units so equipped) from
outdoor section.
4. Remove inner filter track from shipping position in outdoor
section. Position inner filter track so the track is facing
outward from the unit. Install the filter track with 4 screws
provided.
5. Apply seal strip (provided) to back flange of both hood
sides where hood side connects to the unit back panel. (See
Fig. 19.)
6. Apply seal strip (provided) to top flange of both hood sides
where hood sides connect to the hood top panels. (See Fig.
19.)
HOOD
SIDE
HOOD TOP
(TOP HALF)
HOOD
SIDE
RETURN AIR
SECTION
Fig. 18 --- Outdoor- -Air Hood Compartment
Shipping Location
NOTE: For units with manual dampers, replace the end filters
with the manual dampers. Install the filter in the center between the
manual dampers.
NOTE: For filter removal, remove the four screws holding the
filter retainer. The filters can then be removed, cleaned, or replaced.
Install the filters by reversing the procedure.
Manual Damper Assembly
For units equipped with manual dampers, the assembly process is
similar to the outdoor air hood for units with economizers. There
are two slide dampers shipped with the unit to allow for manual
setting of the outside air volume. When assembling the hood, place
one of the manual slide dampers in each of the end positions and
the remaining filter in the center position. The manual dampers can
then be moved to the appropriate position and then locked into
place using the screws mounted in the adjustment slots. (See Fig.
21.)
Step 9 —Position Optional Power Exhaust or

Barometric Relief Damper Hood

The optional power exhaust or barometric relief dampers are
HOOD TOP
(BOTTOM HALF)
shipped assembled and tilted back into the unit for shipping.
Brackets and extra screws are shipped in shrink wrap around the
dampers.
C06283
25
7. Install hood sides to the back panels using the screws from
Step 2. The sloped flanges point outward. The drip edges of
the side panels should face outward as well. The filter
guides should face inward to hold the filters in place. (See
Fig. 19.)
8. Apply seal strip along the entire length of the bottom flange
of the hood top. (See Fig. 19.)
9. Install the bottom part of the hood top using 4 screws
provided. (See Fig. 19.)
10. Remove the packaging from filters (3) and install into the
filter tracks. Slide the filters to the sides then place the last
filter into the center of the filter track.
11. Install the filter retainer track along the bottom edge of the
outdoor air hood using 4 screws provided. (See Fig. 19.)
12. Install top section of the outdoor air hood using 9 screws
provided. (See Fig. 19.) See Fig. 20 for a picture of the
assembled outdoor air hood.
1. Remove 9 screws holding each damper assembly in place.
(See Fig. 22.) Each damper assembly is secured with 3
screws on each side and 3 screws along the bottom. Save
screws.