Vii-Accessories - Lennox LGH094U Unit Information

VII-ACCESSORIES

The accessories section describes the application of most of
the optional accessories which can be factory or field installed
to the LGH units.
A-Mounting Frames
When installing units on a combustible surface for downflow
discharge applications, a C1CURB roof mounting frame is
used. The roof mounting frames are recommended in all
other applications but not required. If the LGH units are not
mounted on a flat (roof) surface, they MUST be supported
under all edges and under the middle of the unit to prevent
sagging. The units MUST be mounted level within 1/16" per
linear foot or 5mm per meter in any direction.
The assembled C1CURB mounting frame is shown in fig­
ure 40. Refer to the roof mounting frame installation instruc­
tions for details of proper assembly and mounting. The roof
mounting frame MUST be squared to the roof and level be­
fore mounting. Plenum system MUST be installed before
the unit is set on the mounting frame. Typical roof curbing
and flashing is shown in figure 41. Refer to the roof mount­
ing frame installation instructions for proper plenum con­
struction and attachment.
ASSEMBLED ROOF MOUNTING FRAME
SUPPLY AIR
OPENING
RETURN AIR
OPENING
FIGURE 40
B-LP / Propane Kit
Natural to LP /propane kit includes a spring kit and three
stickers. In addition, the LP kit contains either six, nine, or
eleven burner orifices. For more detail refer to the natural to LP
gas changeover kit installation instructions.
C-Dirty Filter Switch S27
The dirty filter switch senses static pressure increase indi­
cating a dirty filter condition. The switch is N.O. and closes
at 1" W.C. (248.6 Pa) The switch is mounted on the top filter
channel corner. Wiring for the dirty filter switch is shown on the
temperature control section (C2) wiring diagram in back of this
manual.
TYPICAL FLASHING DETAIL
UNIT BASE
BOTTOM
FIBERGLASS
INSULATION
(Furnished)
NAILER STRIP
(Furnished)
RIGID INSULATION
(Field Supplied)
ROOF
MOUNTING FRAME
(Extends around entire
perimeter of unit)
D-Transitions
Optional supply/return transitions LASRT08/10 is available
for use with the LGH 7.5 ton units and LASRT10/12 is avail­
able for the 8.5 and 10 ton units, utilizing optional C1CURB
roof mounting frames. LGH 12.5 ton units will use LAS­
RT15 with C1CURB roof mounting frame. Transition must
be installed in the C1CURB mounting frame before mount­
ing the unit to the frame. Refer to the manufacturer's in­
structions included with the transition for detailed installa­
tion procedures.
E-LAOAD(M) Outdoor Air Dampers (all units)
LAOAD(M) consists of a set of dampers which may be man­
ually or motor (M) operated to allow up to 25 percent out­
side air into the system at all times (see figure 42 or 43). Ei­
ther air damper can be installed in LGH units. Washable
filter supplied with the outdoor air dampers can be cleaned
with water and a mild detergent. It should be sprayed with
Filter Handicoater when dry prior to re-installation.
F-Supply and Return Diffusers (all units)
Optional flush mount diffuser/return FD11 and extended mount
diffuser/return RTD11 are available for use with all LGH units.
Refer to manufacturer's instructions included with transi­
tion for detailed installation procedures.
G-Blower Proving Switch S52
The blower proving switch monitors blower operation and
locks out the unit in case of blower failure. The switch is
N.O. and closes at .14" W.C. (34.9 Pa) The switch is mount­
ed on the upper left hand corner of the blower deck. Wiring
for the blower proving switch is shown on the temperature con­
trol section (C2) wiring diagram in back of this manual.
Page 60
UNIT BASE
RAIL
COUNTER FLASHING
(Field Supplied)
CANT STRIP
(Field Supplied)
ROOFING
MATERIAL
FIGURE 41