Lincoln 3270-2 Convection Oven User Manual


 
Impinger X2 – Digital Service Manual – Dom & Int’l
7
Oven will not heat Gas supply Check for adequate gas supply to oven.
Manual gas shut off valve Check to see that the manual gas shut off valve is
open. Also, check flexible gas line connection for any
damage.
Main fan motor Check for main fan operation. If it is not operating, refer
to “Oven fan will not run”.
Relay, main fan Check for 208/240VAC supplied to relay terminal #13.
If voltage is not present, trace wiring back to power
supply. If voltage is present, check for 208/240VAC at
terminal #14. If there is no voltage at terminal #14, and
the relay is energized, replace the main fan relay.
Air pressure switch, Main fan
motor
Check for 208/240VAC to the air pressure switch. If no
voltage is present, trace wiring back to main fan switch.
This normally open switch should close when the main
fan is activated. Check air switch tube for blockage or
any obstructions, repair as needed. Refer to the
“Removal and installation” section for proper
adjustment of air pressure switch. Replace air pressure
switch as needed.
Hi-limit thermostat, oven cavity Terminals are normally closed. If open, reset
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.
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.
Motor, burner blower Check for 208/240VAC supplied to the burner blower
motor. If no voltage is present, trace wiring back to the
hi-limit thermostat. If voltage is present, and the motor
is not turning, check for opens, shorts or grounds.
WITH POWER OFF: Check for locked rotor.
Replace burner blower motor as needed.
Air pressure switch, burner
blower motor
Check for 24VAC to the air pressure switch. If no
voltage is present, trace wiring back to the
burner/control transformer. This normally open switch
should close when the burner blower motor is
activated. Check air switch tube for blockage or any
obstructions, repair as needed. Refer to the “Removal
and installation” section for proper adjustment of air
pressure switch. Replace air pressure switch as
needed.
Burner control Check for 24VAC supply to the ignition control. If no
voltage is present, trace wiring back to centrifugal
switch of burner blower motor. If voltage is present,
check for 24VAC at pin #3 and ground (pilot valve).
NOTE: The Honeywell ignition control has a 30 second
pre-purge (time delay) built in. If voltage is not present,
replace ignition control. If the pilot valve is energized,
check to see that the high voltage igniter circuit is also
energized. To check, turn power off, disconnect the
igniter lead from the ignition control. Turn power on. If
no spark is visible, replace burner control. If a spark is
visible at burner control, proceed.
Pilot valve Check for 24VAC supplied to pilot valve. If no voltage is