Lincoln Impinger 1454-000-E, Service Manual

Impinger I -–Adv Digital – Electric Service Manual - International 

7

24VAC at transformer secondary. If there is primary 
voltage, but no secondary voltage, replace control 
transformer. 

Oven control 

Check for 24VAC supply to oven control. If no voltage is 
present, trace wiring back to control transformer. Check 
for supply voltage to oven control. If no voltage is 
present, trace wiring back to hi-limit thermostat. If 
voltage is present, check for a read-out on the display. If 
there is no read-out on the display, replace oven control. 
If there is a read-out on the display, set the oven control 
to maximum temperature (see installation operations 
manual for temperature adjustment). With the oven 
control at maximum temperature, check for supply 
voltage to the heat contactor. If there is voltage at the 
heat contactor, proceed to “Heat contactor “. If there is 
no voltage at the heat contactor, trace wiring back to the 
oven control. If there is no voltage output at the oven 
control, check the read-out on the oven control. If the 
oven control reads “PROBE FAIL” this indicates that the 
thermocouple has failed or become disconnected from 
the oven control  

Contactor, hi-limit (Model 
1421-000-E only) 

Check for supply voltage to contactor coil. If no voltage 
is present, trace wiring back to oven cavity hi-limit 
thermostat. If supply voltage is present at the coil, check 
to see that contacts are closed. If there is voltage to the 
coil and the contacts are not closed, replace contactor.  

Thermocouple 

Check to see that the thermocouple is securely 
connected to the oven control. If the thermocouple is 
connected to the oven control, and the display 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 supply 
voltage output to the temperature regulation valve, 
replace the oven control. If there is supply voltage output 
to the heat contactor, proceed. 

Heat contactor 

Check for supply voltage to the heat contactor. If voltage 
is present, listen for contacts to open and close. Also 
check for opens or shorts in the operating coil. Replace 
heat contactor as needed. 

Intermittent heating 

Thermal/overload of main fan  
motor 

The main fan motor is equipped with internal thermal 
protection and will cease to operate if overheating 
occurs. As the motor overheats and cool, this will cause 
the heating system to cycle on and off intermittently. 
Improper ventilation or lack of preventive maintenance 
may cause this problem. Also most of the problems 
listed under “Oven will not heat” can cause intermittent 
failure. 

Conveyor will not run 

Incoming power supply 

Check circuit breaker, reset if required. Check power