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SGH/SCH036, 060, 120, 240
NOTICE
Roof Damage!
This system contains both refrigerant and oil. Some
rubber roofing material may absorb oil, causing the
rubber to swell. Bubbles in the rubber roofing
material can cause leaks. Protect the roof surface to
avoid exposure to refrigerant and oil during service
and installation. Failure to follow this notice could
result in damage to roof surface.
Use of this unit as a construction heater or air conditioner is
not recommended during any phase of construction. Very
low return air temperatures, harmful vapors and operation
of the unit with clogged or misplaced filters will damage the
unit.
If this unit has been used for heating or cooling of buildings
or structures under construction, the following conditions
must be met or the warranty will be void:
S
The vent hood must be installed per these installation
instructions.
S
A room thermostat must control the unit. The use of
fixed jumpers that will provide continuous heating or
cooling is not allowed.
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A pre-filter must be installed at the entry to the return air
duct.
S
The return air duct must be provided and sealed to the
unit.
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Return air temperature range between 55°F (13°C) and
80°F (27°C) must be maintained.
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Air filters must be replaced and pre-filters must be
removed upon construction completion.
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The input rate and temperature rise must be set per the
unit rating plate.
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The heat exchanger, components, duct system, air
filters and evaporator coil must be thoroughly cleaned
following final construction clean-up.
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The unit operating conditions (including airflow, cooling
operation, ignition, input rate, temperature rise and
venting) must be verified according to these installation
instructions.
NOTE - The Commonwealth of Massachusetts
stipulates these additional requirements:
S
Gas units shall be installed by a licensed plumber
or gas fitter only.
S
The gas cock must be “T handle” type.
Unit Support - Downflow Discharge
Applications
Installer's Roof Mounting Frame
Many types of roof frames can be used to install the unit
depending upon different roof structures. Items to keep in
mind when using the building frame or supports are:
1- The base is fully enclosed and insulated, so an
enclosed frame is not required.
2- The frames or supports must be constructed with
non-combustible materials and should be square and
level to 1/16” per linear foot (5mm per linear meter) in
any direction.
Exception:
1/16” per linear foot to 3/8” per linear foot roof pitch
(5mm per linear meter to 20mm per linear meter)—
Roof curb can be installed level to the roof pitch only if
the unit outdoor air intake is oriented toward the higher
side of the roof pitch.
3- Frame or supports must be high enough to prevent any
form of moisture from entering unit. Recommended
minimum frame height is 14” (356mm).
4- Duct must be attached to the roof mounting frame and
not to the unit. Supply and return plenums must be
installed before setting the unit.
5- Units require support along all four sides of unit base.
Supports must be constructed of steel or suitably
treated wood materials.
NOTE-When installing a unit on a combustible surface
for downflow discharge applications, a Lennox roof
mounting frame is required.
NOTE - Securely fasten roof frame to roof per local
codes.
CAUTION
To reduce the likelihood of supply / return air bypass
and promote a proper seal with the RTU, duct work /
duct drops / diffuser assemblies must be supported
independently to the building structure.
6- 120 units will overhang the roof mounting frame as
FIGURE 2
ROOF CURB
20‐1/2
(521)
3
(76)
UNIT ON CURB LOCATION - SG/SC 120 - in (mm)
53-7/8
(1368)
