Sigma 1457 Oven User Manual


 
Impinger I – Adv Digital – Gas Service Manual – International
10
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 temperature regulation valve, proceed.
Temperature regulation valve Check for supply voltage to the temperature regulation
valve. 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.
Intermittent heating Thermal/overload of main fan
and burner blower motor
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 overheat
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
plug to be sure it is firmly in receptacle. Measure
incoming power, call power co. if required.
Fuse, 10 Amp Check, replace if necessary.
Fuse holder Check, replace if necessary.
Switch, oven power Check for line voltage supplied to switch. If no voltage
is present, trace wiring back to fuse holder. Check
continuity between switch terminals. Replace switch as
needed.
Control transformer Check for supply voltage to primary of control
transformer. If no voltage is present, trace wiring back to
oven power switch. If voltage is present, check for
24VAC at transformer secondary. If there is primary
voltage, but no secondary voltage, replace control
transformer.
Conveyor motor Check for supply voltage to the conveyor motor at
terminal #6 to neutral. If no voltage is present, trace
wiring back to oven power switch. If voltage is present,
but the motor will not run, check the motor windings for
opens or shorts. If any of the above checks fail, replace
conveyor motor.
Capacitor, conveyor motor Check for shorts or grounds. Replace capacitor as
needed.
WARNING: Capacitor has a stored charge, discharge
before testing.
Switch, conveyor reversing Check continuity between switch terminals. Replace
switch as needed.
Oven control If there is voltage supplied to the motor, and the motor
capacitor and reversing switch check good, replace the
oven control.
Conveyor motor runs,
but there is no speed
display
NOTE: Display will indicate
“BELT JAM”
Oven control Check for output voltage from oven control to hall effect