Lincoln 1133-000-A - Manual (Page 13)

Impinger II – Advantage Digital Service Manual - Domestic 13
oven cavity thermostat and retest. If thermostat will not hold
for maximum oven temperature, and oven is not
exceeding temperature setting, check for proper
location of capillary bulb in its spring holder. If the
capillary checks okay, replace the hi-limit
thermostat.
Control transformer Check for 120VAC supply to the primary of the
control transformer. If no voltage is present, trace
wiring back to the main power switch. F voltage is
present, check for 24VAC at the transformer
secondary. If there is primary voltage, but no
secondary voltage, replace the control
transformer.
Oven control Check for 24VAC supply to control. If no voltage
is present, trace wiring back to control
transformer. If 24VAC is present, check for a
read-out on the display. If there is 24VAC
supplied, but there is no read-out on the control
display, replace the oven control.
If there is a read-out on the control, set the
control to maximum temperature (see installation
operations manual for temperature adjustment).
With the control set at maximum temperature,
check for supply voltage at mercury contactor. If
there is voltage at the mercury contactor,
proceed to “mercury contactor” for next check. If
there is no voltage at the mercury contactor,
trace wiring back to the oven control. If there is
no voltage output at the oven control, check the
read-out on the control. If the control reads
“PROBE FAIL”, this indicates that the
thermocouple has failed or become disconnected
from the oven control.
Thermocouple Check to be sure that the thermocouple is
securely connected to the oven control. If the
thermocouple is connected to the oven control,
and the control indicates “PROBE FAIL”,
disconnect the thermocouple from the oven
control and measure the resistance of the
thermocouple. The thermocouple should read
approx. 11
Ω. If these readings are not achieved,
replace the thermocouple. If these readings are
correct, proceed.
Oven control If the thermocouple checks good, but the oven
control display indicates that there is a
thermocouple failure, replace the oven control. If
the oven control indicates a temperature reading
but the oven will not heat, proceed.
Thermocouple WITH POWER ON AND THERMOCOUPLE
ATTACHED TO THE OVEN CONTROL:
Measure the DC millivolt output of the
thermocouple. Refer to the thermocouple chart
(located in the “Removal” section of the manual)
for proper millivolt readings. If these readings are
not achieved, replace thermocouple.
Oven control If the thermocouple checks good, but there is no
voltage output to the mercury contactor, replace
the oven control. If there is voltage output to the
mercury contactor, proceed.
Mercury contactor Check for supply voltage to the contactor coil. If
voltage is present and the contactor will not