Carrier WeatherExpert 50LC14, Installation Instructions Manual, Page: 25 / 84

25
POSITIONING ON CURB
Position unit on roof curb so that the following clearances are
maintained:
1
/
4
-in. (6 mm) clearance between the roof curb and
the base rail inside the right and left,
1
/
2
-in. (12 mm) clearance
between the roof curb and the base rail inside the front and back.
This will result in the distance between the roof curb and the
base rail being approximately equal to detail A and detail B in
Fig. 19-21.
Do not attempt to slide unit on curb after unit is set. Doing so will
result in damage to the roof curb seal.
Although unit is weatherproof, guard against water from higher
level runoff and overhangs.
After unit is in position, remove rigging skids and shipping
materials.
Step 7 — Horizontal Duct Connection
Refer to Fig. 2-16 for locations and sizes of the horizontal duct
connections. Note that there are two different return air duct con -
nection locations – one for unit without an economizer (on back
side of unit) and a different one for unit equipped with an econo -
mizer (on left end, under the economizer hood). The supply air
duct connection is on the back side. See Fig. 23 for top view de -
picting typical horizontal duct arrangements.
Field-supplied (
3
/
4
-in.) flanges should be attached to horizontal
duct openings (see Fig. 23) and all ductwork should be secured to
the flanges. Insulate and weatherproof all external ductwork,
joints, and roof or building openings with counter flashing and
mastic in accordance with applicable codes.
NOTE: 50LC size 17 to 26 units are factory assembled as either
dedicated horizontal or vertical units. These units cannot be field
converted.
Fig. 23 — Horizontal Duct Opening Dimensions
Step 8 — Install Outside Air Hood (Factory
Option)
The outside air hood for the factory-option economizer is shipped
in knock-down form and requires field assembly. The panel for the
hood top is shipped on the end of the unit (see Fig. 24). The re -
maining parts for the hood assembly (including side panels, filters
and tracks) are shipped in a carton that is secured to the rear of the
blower assembly. Access the carton location through rear panel
(see Fig. 25).
.
Fig. 24 — Hood Top — Shipping Position
Fig. 25 — Hood Package — Shipping Location
To remove the hood parts package:
1. Remove the back blower access panel.
2. Locate and cut the strap, being careful to not damage any
wiring.
3. Carefully lift the hood package carton through the back
blower access opening.
To assemble the outside air hood (see Fig. 26 for hood compo -
nent locations):
1. Remove hood top panel from shipping position on unit
end.
2. Install filters supports (Item #1) to the upper end panel
using the screws provided.
3. Install each deflector (Item #8) on to each filter support
(Item #1) using the screws provided.
4. Apply seal strip to mating flanges on side plates of hood
(Items #4 and #5).
5. Secure side panels (Items #4 and #5) to upper panel using
the screws provided.
6. Apply seal strip to mating flange of the hood (see Fig. 26).
7. Secure hood top (Item #3) to upper panel using the screws
provided. (On 44-in. chassis, remove the screws from
across top cover of unit. The rear flange of hood top will
slide behind unit top over flange.)
8. Secure side retainers (Item #6) to side panels (Items #4
and #5) using the screws provided, screwing from outside
of the hood.
9. Secure each central retainer (Item #2) to the hood top
(Item #3). Then align central retainers to holes located on
filter support (Item #1), so central retainer is perpendicular
to hood and each filter support. Secure using screws pro -
vided.
10. Apply seal strip to top diverters (Item #7).
11. Secure top diverters (Item #7) to hood top (Item #3).
12. Install outdoor air screens by sliding them into each of the
four spaces created by the hood, filter support and central
retainers. To do so, first insert the air screens into pocket
created at the end of hood (Item #3), then fully put the air
Return Air Duct
with Economizer
Return Air Duct
without
Economizer
Horizontal
Supply Air
SUPPLY
RETURN
WITHOUT
ECONOMIZER
RETURN WITH
ECONOMIZER
Location
Back Back Left End
Height - in. (mm)
15 7 /
8
(402) 49 3 /
8
(1253) 18 3 /
8
(467)
Width - in. (mm)
29 3 /
4
(756) 23 3 /
8
(593) 61 5 /
8
(1564)
HOOD TOP
SHIPPING
POSITION
HOOD
PACKAGE