Lincoln 1100 Series Conveyor Drive Stepper Motor, Time/Temp Display, VAC Power Supply

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 probe-2
	yellow wires, thermo-
	couple probe probe-1
	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 - 1-5, 2-6, 3- 7, 4-8, each reading should be approximately 2 ohms. If motor shaft will not turn,

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 12-15 VAC. Voltage across terminals 1 and 3 on the time/temp. display should read 12-15 VAC. Terminals 1-2 and 2-3 should be 1/2 the voltage reading to

1-3. If the above secondary readings are not achieved, replace transformer. If proper voltage is present at terminals 1, 2, and 3 on time/temp display, but the display is not lighted, recheck all connections for tightness. If time/temp display is still not operating, replace the time/temp display.

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

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