Impinger II – 1100-000-A Series (SN 2038615 & Below) Service Manual –Int’l
14
Speed adjustment
potentiometer This is a 0 to 10K ohm, 1 turn potentiometer.
With power off, remove the black and white
pot. leads from the motor control board at
terminals P1 and P2. Place the meter leads on
the black and white pot. leads. Rotating the
pot. slowly, from low to high, the meter reading
should show an even transition from 0 to 10K
ohms ± 5%. There should be no dead or open
spots throughout the rotation of the
potentiometer. Check both pot. leads to
ground. There should be no continuity to
ground. If any of the above checks fail, replace
the potentiometer.
Magnet Check to insure that the magnet (cemented to
shaft of conveyor drive motor) has not been
damaged, or come loose from the motor shaft.
Re-glue or replace as needed.
Hall effect sensor Check for any physical damage to hall effect
sensor (mounted on conveyor drive motor).
Check all wiring and connections for damage.
Replace as needed.
Hall effect sensor cable Check continuity through the wires in the cable.
Check all wiring and connections for visible
damage. Replace as needed.
DC motor control board With motor running, measure DC voltage
across the red wire and black wire in the hall
effect cable (all wires must be connected
during this test). Voltage reading should be
approx. 12VDC and steady. If this reading is
not achieved, replace DC motor control board.
Hall effect sensor With the motor running at maximum speed,
measure the frequency across the white wire
and the black wire in the hall effect cable (all
wires must be connected during this test).
Reading should be approx. 327 Hz. And
steady. If there is no reading, replace hall effect
sensor. If the reading is unsteady, calibrate the
DC motor control board.
Display transformer Measure the transformer primary for supply
voltage input. If voltage is not present, trace
wiring back to the oven fan switch. Measure
the secondary output, which will normally be
12-15VAC. Voltage across terminals 1-3
should be 12-15VAC. Terminals 1-2 and 2-3
should be ½ the voltage reading 1-3. If the
above secondary readings are not achieved,
replace transformer.
Temperature display
inoperative
Temperature display If proper voltage is present at terminals 1,2 and
3 on temperature display, but the display is not
lighted, recheck all connections for tightness. If
temperature display is still not operating,
replace the temperature display.
Temperature display
inaccurate, or erratic Thermocouple Place the thermocouple of a pyrometer into the
center of the top finger. The pyrometer will
indicate oven temperature. Measure DC
millivolts of thermocouple at the temperature
display. See thermocouple chart in “Removal
and Installation” section for proper readings.
Replace thermocouple if proper readings are
not achieved. If readings are correct on the
thermocouple, recalibrate or replace