Filter
Top Products
Impinger II – 1100-000-A Series (SN 2038615 & Below) Service Manual –Int’l
12
Main fan motor Check for main fan operation. If fan is not
operating, refer to "Oven fan will not run".
Air pressure switch This normally open switch should close when
the main fan is activated. Check air switch tube
for blockage or obstructions. Adjust switch if
necessary (see “Removal and installation”
section for instructions). Replace air pressure
switch as needed.
Temperature control Check for supply voltage at temperature
control. If no voltage is present, trace wiring
back to air pressure switch. Turn the
temperature adjustment knob to maximum
temperature position and check for 230VAC at
the load terminals #8 and neutral. If 230VAC is
present and unit is not heating, refer to
“Mercury contactor” for next check. If 230VAC
is not present, proceed.
Thermocouple probe With power on and thermocouple leads
attached to the temperature control board:
measure DC millivolt output of these leads.
Refer to “Removal and installation” for proper
readings. If these readings are not achieved,
replace thermocouple.
Temperature control
potentiometer
Disconnect the potentiometer leads from the
control board. Place ohmmeter test leads on
the blue and green pot. wires. Reading should
be 1K ohms. Place meter leads across the blue
and purple pot. leads and rotate knob from low
to high. Repeat on green and purple leads.
Check for an even rise and fall of ohms reading
to insure that there are no open or dead spots
in the potentiometer. Check each lead to
ground for short circuits. Replace
potentiometer as needed.
Mercury contactor Check for supply voltage to the contactor coil. If
voltage is present and the contactor will not
activate, replace the contactor. Also, check
each contactor for proper high voltage input
and output.
Oven will not heat
Heater elements Check the amp draw on each leg of the power
supply for proper load. Check the oven
specification plate for rating information. If the
amp draw is low or high, check the individual
elements for opens, shorts and proper
resistance. WITH POWER OFF: To check
resistance of the elements, remove all wires
from the elements. The element resistance
should be:
230VAC – 33 ohms approx.
Oven heats with switch off Mercury contactor The mercury contactor has probably
malfunctioned in the closed position. If there is
no voltage to the operating coil, but there is
high voltage at the contactor output, replace
the mercury contactor.
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 then cools, the heat circuit will cycle on
and off intermittently. Improper ventilation or a
lack of preventive maintenance may cause this
condition. Also, most of the problems listed