Sterling RT - Manual (Page 6)

6
III. INSTALLATION
Open all disconnect switches
and secure in that position before installing unit.
Failure to do so may result in personal injury or
death from electrical shock.
Installation must conform with local building codes or
in the absence of local codes with the latest edition
of the National Fuel Gas Code ANSI Z223.1 (N.F.P.A.
No. 54) National Fuel Gas Code.
A heat loss study and a complete layout of the system
should be made fi rst.
When locating the unit in its permanent location, make
certain that the roof is capable of carrying the additional
load of the equipment. Check the unit net weights
section of this manual.
Make certain that clearances are provided for service,
minimum clearance to combustible material and to venting
cap. See Figure 2 for this information.
Ducts connected to units which do not have either a blower
section or a supply plenum must have a removable access
panel in the duct, which is connected to a duct furnace.
The duct openings shall be accessible when the unit is
installed in service and shall be of such size that smoke
or refl ected light may be observed inside the casing to
indicate the presence of leaks in the heating element. The
covers for the panels shall be attached in such manner
as to prevent leaks. Ducts exposed to the outdoors must
be insulated and sealed to prevent water from entering
either the unit or building through the duct.
If a single, double or triple duct furnace only unit is
connected to a return air duct or any other inlet air
restriction, the appliance shall be installed on the positive
pressure side of the air circulating blower.
Remove wooden shipping support
from beneath blower housing of Blower Section
to prevent possible unit damage or improper unit
operation (if applicable).
INSTALLATION CLEARANCES
Minimum clearances to combustible material are shown
on the unit data plate. It is important that clearances be
maintained for servicing the unit (refer to Submittal Insert
for service clearances), and that minimum clearances
are provided from the unit (including vent cap, if Natural
Vent model) to combustible material. Clearances around
the outside air hood (if unit is so equipped) must be
unobstructed. See Figure 2.
MOUNTING ON FIELD FURNISHED SUPPORTS
Single, double, triple duct furnace only models have base
rails which are suitable for mounting either directly on
solid planking or steel channels. Never install the unit on
a soft roof where the rails could sink, reducing clearance
between the bottom panel and the roof, or cause damage
to the roofi ng surface.
All other models must use the following method or an
equivalent when unit supports are fi eld furnished: Each
section of the Rooftop unit must be supported, which
includes supports located at both ends. If the unit consists
of a High CFM Blower section, a DX Coil, a Duct Furnace
and a Supply Plenum, fi ve supports are required. See
Figure 4.
Figure 4
MOUNTING ON ROOF CURB
Assemble and install roof curb per Roof Curb Installation
Instructions. See Figures 5, 6, 7 & 8 for roof opening
sizes, distance between openings and unit relationship
to roof curb.
Support must clear return
air opening and fi t inside
base rail fl ange. See Figures 4 & 13
for this dimension.
Support must fi t
inside base rail
fl anges.