Lincoln Impinger Conveyor Ovens 1634-000-EA - Manual (Page 8)

Low Profile – 1600 Advantage Series Service Manual – International 8
replace the spark generator. If there
is visible damage to the igniter/sensor
assembly, replace. Also check for frayed
or damaged wires in burner tube.
Gas valve Check for supply voltage to gas valve.
If there is no voltage present, check
reset button, check all connections for
tightness. If there still is no voltage at
gas valve, replace ignition control.
If there is voltage present, check for
gas pressure at gas pressure tap located
in gas piping at burner manifold.
If there is no gas pressure, replace
gas valve.
Flame will not stay on Flame sensor To check for flame sensor operation,
connect a digital multimeter (capable
of measuring D.C. micro amps) in
series with the flame sensor wire and
ignition control. Sensor current is 3
micro amps D.C. minimum.
NOTE: The D.C. micro amp test must
be conducted with the oven in low
flame (bypass) operation. Turn the
temperature control to its lowest
setting. If these readings are not
achieved, replace igniter/sensor assy.
Also, check for any type of damage to
flame sensor wire and connections.
Ignition control If there is sufficient flame sensor current,
but the burner will not remain ignited,
check the reset button on ignition control.
NOTE: Check for proper polarity of
the power supply. If all of the above
are OK, replace ignition control.
Pilot lamp is on, Temperature control Check for supply voltage across
But no main flame terminals L2 and 240 on temperature
control board. If no voltage is present,
check wiring back to hi-limit thermostat.
Turn the temperature adjustment knob to
the maximum temperature position and
check for supply voltage at the load
terminal #7 and #8. If voltage is present
and unit is not heating, refer to
“temperature regulation valve” for next
check. If voltage is not present, proceed.
Thermocouple probe With power on and thermocouple leads
attached to board, measure the millivolt
out put of the thermocouple. Refer to the
thermocouple chart in section D for
proper readings.
Temperature control WITH POWER OFF: Remove the
Potentiometer potentiometer leads from the temperature
control board. Place ohm meter test leads
on the blue and green pot leads. Reading
should be 1 K ohms. Place meter leads
across the blue and purple pot leads and
rotate knob from high to low. Repeat on
green and purple leads. Check for even
rise and fall of ohms reading to insure
that there are no open or dead spots in
the potentiometer. Check each lead to
ground for shorts. Replace potentiometer