Lincoln Series 1000, Series 1200 service manual

	Speed Adjustment	This is a 0 to 50k ohm, 10 turn potentiometer.
	Potentiometer	WITH POWER OFF: remove the 3-pin
		potentiometer cable plug from the motor control
		board. With a digital multimeter, check the ohm
		reading across the red lead to the black lead. This
		reading should be 50k ohms ±5% as the
		potentiometer is rotated through its 10-turn rotation.
		Place the meter leads on the red lead and white
		lead. Rotating the potentiometer slowly, from low to
		high, the meter should show an even transition
		from 0 to 50k ohms ±5% through the 10-turn
		rotation of the potentiometer. There should be no
		dead or open spots through the 10 turns of the
		potentiometer. Check all three leads to ground.
		There should be no continuity to ground. If any of
		the above checks fail, replace the potentiometer.
	Conveyor Motor	NOTE: if the conveyor drive motor becomes
	(Stepper)Control	jammed or begins to run at an uncontrolled speed,
		the conveyor motor will stop running. To reset, turn
		off the conveyor switch, wait 10 seconds, turn the
		conveyor switch on. If the motor does not run after
		attempting re-set, check for 2 to 29 VAC across the
		motor terminal 1 to 2 and 3 to 5 on the conveyor
		motor control. If voltage is not present at both sets
		of terminals, replace control.
	Conveyor Drive	Check the drive sprocket on motor output shaft to
	(Stepper)Motor	insure that is tight. Check motor windings;
		measurements should be approximately 2 ohms.
		Terminal 1-5, 2-6, 3-7, 4-8. WITH POWER OFF:
		Turn the motor shaft to check for jammed gear box.
		If motor shaft will not turn, replace conveyor
Time/Temp Display		drive(stepper) motor.
	12.6 VAC Power Supply	Measure the transformer primary for a nominal 120
inoperative		VAC input. Measure the secondary voltage output
		which will be 12.5 to 15 VAC normally. Recheck
		secondary output at rear of Time/Temp Display.
		Terminals 1 to 3 should read 12.5 to 15 VAC.
		Terminals 1 to 2 and 2 to 3 should be 1/2 of the
		reading across 1 to 3. If you do not get the above
		secondary readings, replace the transformer. If 120
		VAC primary voltage is not available, refer to the
		schematic and trace circuit for incoming power
		failure. There is a 4-amp fuse in each red
		secondary lead. These may be jumpered (for test
		only) to determine if they are defective or
NOTE		intermittent.
	(Dual Belt Ovens)	Dual belt ovens utilize a double pole double throw
		switch, which allows either of the optical encoders
		to be read from a single Time/Temp. Display.
		Check the switch and replace as needed.
Temp Display out or	NOTE: Time/Temp displays	Place your pyrometer thermocouple into the center
inaccurate	use two types of temperature	between fingers T2 and T3 in the oven. Disconnect
	sensor, Thermistor Probe - 2	the yellow tipped thermistor leads from the
	yellow wires, Thermocouple	time/temp. terminals 9 and 10. Measure the
	Probe - 1 red wire and 1	resistance of the thermistor probe.
	white wire
	Thermistor Probe	See chart on page 72 for proper resistance
		readings. Inspect the thermistor bulb for its proper
		location in its spring holder. Check for shorts in
		leads where they enter the sensor bulb. Also check
		each thermistor lead for short to ground.
36		Impinger I -–1000 Series Service Manual - International