Reznor YDSA Unit Installation Manual - Manual (Page 18)

Form I-Y, P/N 273646R6, Page 18
5.3 Mounting on a Roof Curb (cont'd)
5.0 Mounting (cont'd)
5.3.2 Curbs for Horizontal Airflow (cont’d)
Installation Instructions for Cabinet Size 3 Horizontal Airflow Roof Curbs, Option CJ48 and Option CJ55
1. Refer to FIGURE 12 shown on page 17 and position
the two curb ends (letter A) and four side pieces
(letters B, C, D, E). Verify the side pieces are
positioned correctly (shorter piece at the inlet air end
and longer piece at the control end of the unit).
2. Attach Curb Corners.
Using the hardware provided (lag screw and washer
in top holes; cap screw, washer, and nut in the 4 holes
below the wood nailer), create the four corners by
attaching the ends to the side pieces.
3. Attach the two Side Splice Plates (letter F).
Use the hardware provided (lag screw and washer in
top holes; cap screw, washer, and nut in the 4 holes
below the wood nailer) to attach splice plates ( letter F)
joining the side pieces ( letters B&D and letters C&E)
to complete the perimeter of the curb.
4. Assemble the Return Air Plenum.
Position two sides (letter G) between the return air
duct bottom (letter K) align the holes in each and
using the sheet metal screws, assemble these three
sheet metal pieces. Then using the holes in the curb
sides (letters D & E), align the return air plenum sub
assembly holes on each end with the holes in the curb
sides and attach using the sheet metal screws.
5 Assemble the Supply Air Plenum.Position two sides
(letter G) between the supply air duct bottom (letter
H) align the holes in each and using the sheet metal
screws, assemble these three sheet metal pieces.
Then using the holes in the curb sides (letters D &
E), align the supply air plenum sub assembly holes on
each end with the holes in the curb sides and attach
using the sheet metal screws.
6. Attach the Duct Flanges (letters L & M).
Using sheet metal screws, attach the supply air duct
flange (letter M) around the supply opening and the
smaller return air duct flange ( letter L) around the
return air opening. If the installation does not have
return air, attach a field-fabricated cover over the
return air opening.
7. Check the Squareness, Level the Curb, and Install
the Flashing.
Adjust the curb so that the diagonal measurements
are equal within a tolerance of ±1/8”(3mm).
To ensure a good weatherproof seal between the
cabinet curb cap and the perimeter of the curb, the
curb must be leveled in both directions with no twist
end to end. Shim as required and secure the curb to
the roof deck.
Install field-supplied flashing.
8. Before placing the unit on the curb, apply 1/4” x
1-1/4” foam sealant tape to both the top surface of
the curb rails and the top surface of the duct sides.