Lincoln 3270-2 Convection Oven User Manual


 
Impinger X2 – Digital Service Manual – Dom & Int’l
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replace the oven control. If the oven control indicates a
temperature reading, but the oven will not heat,
proceed.
Main gas valve Check to see that the switch on the valve is in the “ON”
position. Check for 24VAC supplied to main valve. If
there is voltage present, check to see that valve is
opening. Connect manometer to pressure tap on outlet
side of valve. If there is voltage to the valve, but no
output gas pressure, replace the valve.
Temperature regulation valve Check for 208/240VAC at temperature regulation valve.
If no voltage is present, trace wiring back to electronic
temperature control. If voltage is present, listen for
valve to open and close. Also check for opens or shorts
in the operating coil. Replace temperature regulation
valve as needed.
Oven control Check for 3 – 24VDC from the oven control at terminals
#J2-6 and J2-9. If there is no output voltage, replace
oven control. If there is output voltage,
Proceed.
Modulating valve Check for 3-24VDC at the modulating valve. If no
voltage is present, trace wiring back to the oven
control. If voltage is present, listen for valve to open
and close. Also check for opens or shorts in the
operating coil. Replace modulating valve as needed.
Intermittent heating Thermal/Overload of main fan
and burner blower motors
The main fan motor and burner blower motor are
equipped with internal thermal protection and will cease
to operate if overheating occurs. As the motors over-
heat and then cool, this will cause the units to cycle on
and off intermittently. Improper ventilation or lack of
preventive maintenance may cause this. Also, most of
the problems listed under “Oven will not heat” can
cause intermittent failure.
Conveyor will not run NOTE: The ovens may contain two, three or four conveyor drive systems using like
components. The trouble shooting sequence will be the same for each of the conveyor
drive systems
Power supply Check circuit breakers, reset if required. Check power
plug to be sure it is firmly in receptacle. Measure
incoming power, call power co. if needed.
Switch, oven power Check continuity between switch terminals. Replace
switch as needed.
Relay, main fan Check for 120VAC supplied to relay terminal #13. If
voltage is not present, trace wiring back to power
supply. If voltage is present, check for 120VAC at
terminal #14. If there is no voltage at terminal #14, and
the relay is energized, replace the main fan relay.
Transformer, burner/control Check for 208/240VAC supplied to primary of
transformer. If no voltage is present, trace wiring back
to the main fan switch. If voltage is present, check for
24VAC at transformer secondary.
NOTE: This is a dual secondary transformer, it is
important to check BOTH 24VAC outputs.
If there is primary voltage but no secondary voltage,
replace burner/control transformer.
Switch, conveyor reversing Check for continuity between switch terminals. Replace
switch as needed.
Conveyor motor Check for 208/240VAC supplied to the motor. I no
voltage is present, trace wiring back to the reversing
switch. If voltage is present, check motor windings for
opens or shorts.