Trane GRAA Installation Manual page 5

Figure 2 - Roof Opening Specifications
20-7/8"
(530mm)
Section
X-X
Opening
* Dimension "A" applies to the distance between roof openings
(only on units with a supply plenum: also refer to Figure 4).
Refer to Figure 4 for Section X-X and Y-Y details.
RA* = Rooftop Arrangement
Note: All roof opening dimensions shown have been calculated to
include one inch (25mm) clearance on each side of the ductwork
openings.
GRAA-IN-1
WARNING!
To avoid any property damage
or personal injury, it is the
installer's responsibility to make
sure that the installation will not
impair the function of this curb,
or the unit to be installed.
All curbs must be mounted on level
areas. The roof must be suitable
to support the weight of both the
curb and the unit to be mounted.
The enclosed area of the roof curb
must comply to required
clearances to combustible
materials. If the roof construction
is made of combustible materials,
the enclosed roof curb area must
meet the following requirements:
1. Ventilate this area.
2. Leave area open (however, this
may elevate higher sound
levels).
3. Cover this area with
non-combustible material,
which utilizes an "R" value of
5.0 minimum.
A*
Return
Air
Section
Y-Y
RA * Capacity
C 10 thru 40 50-7/8 " (1292)
E 10 thru 40 50-7/8" (1292)
20-7/8"
(530mm)
E*
Supply
Air
Opening
A ** (mm)
Position and assemble the curb,
referring to Figures 1 thru 8, 17 and
18 and the following procedure:
1. All hardware used for these
assembly procedures is
included with your curb, and
should be used. Do not tighten
any hardware until the curb is
completely level and square,
and installed in a suitable
position on the roof, with proper
alignment to the roof/unit
opening(s).
2. Position and install the end and
side curb rail sub-assemblies,
aligning around the roof
opening location(s).
3. Position and install the inner
cross brace(s) and ductwork
brackets as shown.
4. Secure the roof curb to the roof
decking.
5. Install the field supplied
flashing/ materials.
6. Apply the gasketing (included
with the kit) on the top flanges/
surfaces of the curb as shown.
WARNING!
To avoid any property damage
or personal injury, it is the
installer's responsibility that the
roof curb and unit must be
completely sealed, preventing
any water or air leakage/damage.
Dimension
Capacity
E * (mm)
26"
10/15
(660)
37"
20/25/50
(940)
48"
30/35/60/70
(1219)
53-1/2"
40/80
(1359)
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