Lincoln Series 1000, Series 1200 service manual

Main Flame will not	Flame Monitor	(There should be a visible main flame at this time.)
stay lit		To check for flame monitor operation, connect a
		digital volt meter (capable of measuring D.C. micro
		amperes) between the flame sensor and terminal
		#15 on the flame monitor. The flame monitor
		requires a minimum of 4 micro amp. D.C. for proof
		of flame. If these readings are not achieved,
		replace sensor assembly. Also check for any type
		of damage to flame sensor wire and connections.
		If the reading is above the minimum required, and
		the flame monitor will not supply 220 VAC to the
		relay coil, replace the flame monitor.
Intermittent Heating	As Follows	Both the main fan motor and burner blower motor
		are equipped with thermal protection and will cease
		to operate if overheating occurs. This can cause
		the units to cycle on and of intermittently. This may
		be caused by improper ventilation. Also, most of
		the problems listed under "oven will not heat" can
		cause intermittent failure.
Conveyor will not run	Conveyor Switch	Check for 120 VAC to conveyor switch. If no
		voltage is present, trace wiring back to the power
		supply. WITH POWER OFF: Check continuity
		between switch terminals
	Conveyor Fuse(3A)	Check, replace if necessary.
	Fuseholder	Check, replace if necessary.
	Conveyor Control	Check for 120 VAC supply to primary (Stepper)
		Transformer of transformer, if voltage is not
		present, trace wiring back to the fuseholder. If
		voltage is present, check for output voltage from
		the transformer secondary. NOTE: this control
		transformer outputs (2) secondary voltages: Red
		Leads 29 VAC Brown Leads 10 VAC. If BOTH
		secondary voltages are not present, replace the
		transformer.
	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(Stepper)	NOTE: if the conveyor drive motor becomes
	Control	jammed or begins to run at an uncontrolled speed,
		the conveyor motor will stop running. To reset, turn
		off the conveyor switch, wait 30 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 terminals 1 to 2 and 3 to 5 on, the conveyor
		motor control. If voltage is not present at both sets
		of terminals, replace control.

50 Impinger I -–1000 Series Service Manual - International