Glow-Bar Igniter; Oven Burner Ignition System; Oven Components And Replacement - LG LRG30855ST Technical Service Manual

Oven Components and Replacement

Oven Burner Ignition System

The oven bake and broil burners are ignited by a
glow-bar ignition system. The igniter is a Norton
style rectangular glow-bar. The bake and broil
ignition circuits consist of the electronic control,
an igniter and an oven safety valve.
Note: The oven safety valve and pressure
regulator will be supplied as a complete
assembly, and is sometimes referred to as a gas
valve, control valve, or a combi-valve.
The three components are wired in series for
each cooking function.
The most important points to know about the
ignition system are:
• THE IGNITER RESISTANCE DECREASES
AS THE IGNITER SURFACE
TEMPERATURE INCREASES.
• THE SAFETY VALVE OPERATES BY
CURRENT, NOT VOLTAGE.
From a cold start, the igniter needs 30 to 60
seconds, with a minimum of 116 volts applied, to
reduce its electrical resistance enough to provide
a minimum of 2.9 amps of current flow in the
series circuit. This is the required current flow
needed for the safety valve to open and supply
gas to the burner.
The glow-bar should provide a steady current
flow of between 3.3 to 3.6 amps (3.03 / 3.3 VAC)
in the circuit. At that point the igniter temperature
is between 1800°F to 2500°F (982°C to 1371°C).
The igniter will remain energized at all times
during burner operation. If the igniter glows red
but does not draw at least 2.9 amps, the fault is
usually with the igniter, not the valve.
Always check the gas shut-off valve on the
pressure regulator for a Not On condition.

Glow-bar Igniter

WARNING: This range uses rectangular Norton
glow-bar igniters. They are NOT INTERCHANGE-
ABLE with cylindrical Carborundum glow-bar
igniters. The two types of glow-bar igniters oper-
ate at different amperage and use different gas
valves.
Check the glow-bar circuit with a clamp-on
ammeter. If igniter glows red but circuit does not
draw at least 2.9 amps, the fault is likely with the
igniter, not the valve.
Note: If igniter glows, but ignition does not occur,
be sure the gas shut-off valve on the pressure
regulator is in the open position.
Slow ignition can be caused by one or more of
the following conditions:
1. Blockage of primary air intake: Hole beneath
the bake orifice hood must be open and free
of insulation.
2. Improper alignment of orifice hood and
burner: Orifice must be pointing straight into
burner venturi.
3. Improper air/gas adjustment.
4. Blockage of burner crossover slots: Crossover
slots must be open and free of burrs.
5. Improper installation: Failure to seal all
openings in the wall behind and floor below
range may permit substantial drafts which can
affect ignition.
6. The gas control valve should draw
approximately 3.3 to 3.6 amps when
operating. Check by measuring the amperage
in L1 to the oven control.
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