Lincoln Impinger Conveyor Ovens 1100 Series - Manual (Page 29)

Flame will not stay on Flame Sensor To check for flame sensor operation,
connect a digital multimeter (capable
of measuring D.C. micro amps)
between the flame sensor wire and
terminal “F” on the Honeywell Ignition
Control or terminal 1 on Landis & Gyr
Ignition Control. Sensor current from
Honeywell is 2 to 4 D.C. micro amps.
Sensor current from Landis & Gyr is
3 micro amps minimum.
If these readings are not achieved
replace ignitor/sensor assembly.
Also check for any type of damage to
flame sensor wire and connections.
NOTE: The D.C. micro amp test
must be conducted with the oven in
low flame (bypass) operation.
Power Supply Turn the temperature control to
the lowest setting. If there is
sufficient micro-amp current, but
the flame will not stay lit, check
for proper polarity of the power supply
Ignition Control If there is sufficient flame sensor
current, but the burner will not
remain ignited, check the reset button
on ignition control. If all above are
okay, replace ignition control.
Pilot lamp is on, but Temperature Control Check for 120 VAC across terminals
no main flame 10 and 11 on temperature control
board. If no voltage is present, check
wiring back to the Main Fan Switch.
Turn the temperature adjustment
knob to the maximum temperature
position and check for 120 VAC at
the load terminal (number 9), and
neutral (number 10).
If 120 VAC is present and unit is not
heating, refer to “Solenoid Valve” for
next check. If 120 VAC is not present,
proceed with next step.
Thermocouple Probe With power on and thermocouple
leads attached to board, measure
the millivolt output of these leads.
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 and measure ohms from black
to whiteleads. The reading should be from
approximately 0 to 2.5K ohms as the dial of the
potentiometer is turned through its full rotation.
From black to red leads, the reading should be
approx.2.5K ohms and remain steady throughout
the full rotation of the potentiometer.
If the thermocouple probe and the
control potentiometer check good,
Impinger II - 1100 Series Service Manual - International 29