Lincoln 1600 Intermittent Heating, Thermal/Overload of, Main Fan and Burner, Blower Motors, Board

Intermittent Heating	Thermal/Overload of	The main fan motors and the burner blower motors are
	Main Fan and Burner	equipped with internal thermal protection and will cease to
	Blower Motors	operate if overheating occurs. As the motors overheat and
		then cool, this will cause the units to cycle on and off
		intermittently. Improper ventilation or preventive maintenance
		may cause this. Also, most of the problems listed under
		"Oven will not heat" can cause intermittent failure.
Conveyor will not run	Voltage Supply	Check incoming voltage supply at line 1 to neutral. There
		should be a voltage reading of 120 VAC. If not present, check
		breakers.
	Fan Switch	See procedure for checking at beginning of section.
	10 Amp Fuse	Check and/or replace.
	Fuse holder	Check and/or replace.
	Speed Adjustment	This is a 0 to 10 K ohm, 1 turn potentiometer. With power off,
	Potentiometer	remove the black and white pot leads from the motor control
		board at terminals P1, P2. Place the meter leads on the black
		lead (P2) and on the white lead (P1). Rotating the pot., slowly,
		from low to high, the meter readings should show an even
		transition from 0 to 10 K ohms ± 5%. There should be no
		dead or open spots through out the 1 turn of the pot. Check
		both leads to ground. There should be no continuity to
		ground. If any of the above checks fail, replace the pot
	DC Motor Control	Check for 120 VAC input to the control board at terminals L1
	Board	and L2. If not present, check wiring back to the fuse. If 120
		VAC is present at L1 and L2, check both fuses on control
		board (8A line and 1A armature), check the VDC output at
		terminals A+ and A-. If 120 VAC is present at terminals L1
		and L2, and DC voltage is present A+ and A-, but motor does
		not run, check gear motor as follows.
	Conveyor Gear Motor	If DC voltage is present at A+ and A- and the motor does not
		run, first check the mini breaker and then the conveyor. Refer
		to the next possible cause. Check the leads to the motor for
		evidence of any shorts or opens, and each lead to ground.
		Check motor brushes. From the top of the motor, rotate motor
		shaft to determine if there is a locked rotor or a locked gear
		box (use care so magnet and H.S. board are not damaged).
		Replace motor as needed.
	Conveyor	Check for any mechanical misalignment. Also, check for worn
		bearings. A conveyor belt that is over tightened will cause
		excessive bearing wear and sometimes, irregular speed.

Low Profile – 1600-000-A Advantage Series Service Manual – Domestic 7