Accessories - Lennox LGM Series 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 LGM units.
A-C1/T1CURB
When installing the LGM units on a combustible surface for
downflow discharge applications, the C1/T1CURB 8 inch,
14-inch, 18 inch or 24-inch height roof mounting frame is
used. The roof mounting frames are recommended in all
other applications but not required. If the LGM units are
not mounted on a flat (roof) surface, they MUST be sup-
ported 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 mounting frame is shown in figure 28. Re-
fer to the roof mounting frame installation instructions for
details of proper assembly and mounting. The roof mount-
ing frame MUST be squared to the roof and level before
mounting. Plenum system MUST be installed before the
unit is set on the mounting frame. Typical roof curbing and
flashing is shown in figure 29. Refer to the roof mounting
frame installation instructions for proper plenum construc-
tion and attachment.
B-Transitions
Optional supply/return transitions T1TRAN10AN1 is avail-
able for use with the LGM 3, 4 and 5 ton units and the
T1TRAN20N-1 is available for the 6 ton units utilizing
optional T1CURB roof mounting frames. Transition must
be installed in the C1/T1CURB mounting frame before
mounting the unit to the frame. Refer to the manufactur-
er's instructions included with the transition for detailed
installation procedures.
C-Outdoor Air Dampers
E1DAMP11A-1 manually operated outdoor air damp-
er and E1DAMP21A-1 motorized outdoor air damper is
available for LGM 3 and 4 ton units (see figure 30 or 31).
E1DAMP11AT-1 manually operated outdoor air damp-
er and E1DAMP21AT-1 motorized outdoor air damper
is available for LGM 5 and 6 ton units. Both sets include
the outdoor air hood. The manual damper is set at a fixed
point to bring outside air into the building anytime the
blower is operating.The motorized damper opens when
the blower is operating and the thermostat is sending an
occupied signal to the Unit Controller. If the thermostat
signal is unoccupied, the motorized damper will not open.
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-instal-
lation. Filter Handicoater is R.P. Products coating no. 418
and is available as Part No. P-8-5069.
ASSEMBLED ROOF MOUNTING FRAME
UNIT BASE
BOTTOM
FIBERGLASS
INSULATION
(Furnished)
NAILER STRIP
(Furnished)
RIGID INSULATION
(Field Supplied)
ROOF
MOUNTING FRAME
(Extends around entire
perimeter of unit)
MANUAL OUTDOOR AIR DAMPER
SLIDE DAMPERS
TO ADJUST FRESH
AIR INTAKE
Page 38
FIGURE 28
TYPICAL FLASHING DETAIL
UNIT BASE
RAIL
COUNTER FLASHING
(Field Supplied)
CANT STRIP
(Field Supplied)
ROOFING
MATERIAL
FIGURE 29
FIGURE 30