GM9S96 Service Manual
SERVICING
38
4. Touch one probe of the ohmmeter to the motor frame
(ground) and the other probe in turn to each lead. If
the windings do not test continuous or a reading is
obtained to ground, replace the motor.
5. If the windings have a continuity reading, reconnect
wires. Turn power on to the furnace and turn the ther-
mostat on in the heating mode. Check voltage for
115V at the induced draft motor terminals during the
trial for ignition. If you have 115V and the motor does
not run, replace the induced draft motor.
6. After completing check and/or replacement of induced
draft motor, reinstall burner compartment door.
7. Turn on electrical power and verify proper unit
operation.
A combination redundant operator type gas valve which pro-
vides all manual and automatic control functions required for
WARNING
Single stage gas valves should be tested on the furnace with
24 VAC connected to the gas valve and manometers read-
ing supply line and manifold pressures.
The main burners are used to provide complete combustion
of various fuels in a limited space, and transfer this heat of
the burning process to the heat exchanger.
Proper ignition, combustion, and extinction are primarily due
secondary air, vent and proper seating of burners.
Burners have been redesigned for 34.5” chassis furnaces.
Overall length and width dimensions remain the same as
40” model burners. The burners used 34.5” models have
burner head insert with larger diameter center hole and a
larger number of surrounding holes.
.025 .002
(CARRYOVER SLOT WIDTH)
±
16X
.125 x .030 MIN SLOT
12X Ø.125
Ø.562
WARNING
In checking main burners, look for signs of rust, oversized
and undersized carry over ports restricted with foreign ma-
terial, etc, refer to previous drawing. Burner cross-over slots
should not be altered in size.
Single stage furnaces are factory equipped with #45 gas
-
age. They should be removed and installed with a box-end
wrench in order to prevent distortion. In no instance should
properly.
WARNING
1.
2.
3. -
cal size and angle with proper drill size opening should
be installed.
A
GAS
The length of Dimension “A” determines the angle of Gas
Stream “B”.
GAS
stream.