Trane GRAA - Mounting on Roof Curb; Roof Curb Installation

7
- Electrical
Cabinet
Low
Voltage
Sect
High
Voltag e Sec
I
L
Locate line voltage
disconnect box per local codes. If
mounting the disconnect box to
the
unit,
never
mount
it to
an
unit
access
panel.
Possible
locations include
the front of
the
blower or filter section, the outdoor air
hood
or the
rear of the supply plenum (See Figure 8).
Electrical
conduit must
be
routed so
as
not to
inter-
fere with
removal of any access
panel.
NOTE
:
Should
any or
i g
i nal wire suppl i ed
with the
unit hav
e to be replaced
,
it must
b e
replaced
w
i th
w
iri
ng
h
a
v
i ng a
temp e rature r a
t
i ng
of
at least
105 °
C
(221 ° F) .
DX COIL EQU
I PPED UNITS (OPTIONAL)
See Coil Installation/Maintenance
Manual
for
Refrigerant Piping,
Liquid
and
Suction
Line
Components, Refrigerant
Charging
and Thermal
Expansion
Valve Adjustment. Remove
piping
plate
located
in lower corner next to filter section
and
cut
holes
in plate to allow suction
and liquid line pas-
sage. Provide
weatherproof seal around'suction
and
liquid lines
at
piping
plate when installed.
The DX Coil has
a 300
ft/min. (1.524
m/s)
minimum
and
a
600
ft/min. (3.048' m/s)
maximum
velocity
through
the coil requirement. This is
due
to preven-
tion
of coil icing or
condensate blow-off.
To
calculate
the
velocity
through
the coil, apply
the following for-
mula:
Velocity
Cooling Air
Flow
in CFM (m3/s)
through the
coil ^ Coil Surface Area in
ft2 (m2)
opt i
o
n
al
C
o
nt
rol
s
Jo
u
n ci
ng
Locat
io
n
1Q Back
Panel
OZ
main connection Board
Q High
Voltage
Barrier
Assy
O4
24V Transformer
Q5
High
Voltage Terminal Block
O8
Ground
Lug
O7 Din Mounting Rail
Contactor
or
Starter
1
D3 88 3
S - uisconnect
tJox vocations
Di s
conn e ct
9
D i scon n e c t
B o
x Located
On Int ake
E
n d Pane l
(Ret ur
n
A i r O nl y)
D
(acann e et
B ox Locat ed
On Out s id e
A ir Hood
iii
S U PP L Y AIR
Disconnect
Bo
x
Locat e
d On
Supply
Pl e
num End
Pan e l
D3-9-6-6
Condensate
Drain piping
must have a
P-trap
in
line
immediately
downstream of drain pan connection,
external to
the
unit, to prevent possible outside air
-10-