Conveyor Drive
(Stepper) Motor
Time/Temp Display | 12 VAC Power Supply |
inoperative | (Transformer) |
Time/Temp Display
Temp display out | NOTE: Time/Temp |
or inaccurate | displays use two types |
| of temperature sensors, |
| thermistor |
| yellow wires, thermo- |
| couple probe |
| red wire and 1 white wire |
| Thermistor Probe |
Thermocouple Probe
Power Supply
Impinger II - 1100 Series Service Manual - International
present at both sets of terminals, replace control.
Check the drive sprocket on motor output shaft to insure that it is tight.
WITH POWER OFF: Turn the motor shaft
to check for jammed gear box. Check motor wind ings. Ohm readings on motor terminal -
replace conveyor drive (stepper) motor. Measure the transformer primary for a nominal 120 VAC input, if voltage is not present, trace wiring back to the oven power source. Measure the secondary output, which will normally be
Place the thermocouple of a pyrometer into the center of the top finger. Be sure the tip of the thermocouple is not touching metal. The pyrometer will indicate oven temperature.
Disconnect the thermistor probe leads from the time/ temp display terminals #9 and 10. Measure the resistance of the thermistor probe. See chart in section D, showing probe resistance at various oven temperature. If these readings are not achieved, replace the thermistor probe.
Place your pyrometer thermocouple into the center of the top finger. Measure D.C. millivolts at terminals 9 and 10 on the time/temp display. See thermocouple chart in Section D for proper readings. Connect temperature meter to thermocouple at terminals 9 & 10 on back of the time/temp display. (Be sure to maintain proper polarity on thermocouple connections.) Compare actual oven temperature with the reading at the time/temp display. If the temperature readings match, recalibrate or replace time/temp display. If the readings do not match, replace thermocouple probe.
If a strange or unusual behavior is
45