Lennox LGM092U - Burner Orifice and High Temperature Limits

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STANDARD HEAT (130,000BTUH)
INSERTS (2)
INSERTS (4)
HIGH HEAT (180,000BTUH)
Note - No inserts on
medium heat.
INSERT LOCATION - DIRECT DRIVE ONLY
FIGURE 21
FIGURE 22
TYPICAL GAS BURNER ASSEMBLY
BURNERS
ORIFICE
SENSOR
BURNER
SUPPORT
BURNER
SUPPORT CAP
Orifice
Each burner uses an orifice (two types figure 23) which
is precisely matched to the burner input. Install only
the orifices with the same threads. The orifice is
threaded into the burner manifold. The burner is sup
ported by the orifice and will easily slide off for service.
NOTE-Do not use thread sealing compound on the ori
fices. Using thread sealing compound may plug the ori
fices.
Each orifice and burner are sized specifically to the unit.
Refer to ProductZone@www.davenet.com for correct
sizing information.
5-Primary High Temperature Limits S10
S10 is the primary high temperature limit and is located on
the blower deck to the right of the blower housing.
Primary limit S10 is wired to the A3 ignition control which
energizes burner 1 control (A3). Its N.C. contacts open to
de-energize the ignition control when excessive tempera
ture is reached in the blower compartment. The A55 unit
controller will energize the B4 blower when ever it senses
that the S10 limit has been opened.
If the limit trips the blow
er will be energized. Limit settings are factory set and can
not be adjusted. If limit must be replaced, the same type
and set point must be used.
ORIFICE WITH
PIPE THREADS
Tighten to 6.25 + .5 ft.lbs.
Do not over-tighten.
Tighten to 14 + .5 ft/lbs
Do not over-tighten.
ORIFICE WITH
STRAIGHT THREADS
FIGURE 23