Lincoln 1000 Temperature Control Board, Check for 120 VAC input to temperature control, Amp Fuses

	Temperature Control Board	Check for 120 VAC input to temperature control
		board. If not present, check wiring from fuse holder
		to temperature control board. Turn the temperature
		adjustment dial to the maximum temperature
		position Check for 120 VAC at coil of mercury
		contactor(s). Next, short the leads of thermocouple
		on the temperature control board, check for 120
		VAC at coil of mercury contactor(s). If voltage is
		not present, replace temperature control board. If
		voltage is present proceed.
	Temperature Control	Potentiometer is 0 to 2.5K ohm. WITH POWER
	Potentiometer	OFF: remove the leads from the temperature
		control board terminals 1, 2, and 3 and measure
		ohms from black to white leads. The ohm reading
		should be 0 to approximately 2.5K ohms as the dial
	Thermocouple Probe	Remove thermocouple leads from the temperature
		control board, and measure the millivolt output of
		the leads. Refer to chart in adjustment section for
		proper millivolt readings.
	Mercury Contactor(s)	Check for 120 VAC to the contactor coil. If voltage
		is present and contactor will not activate, replace
		the contactor(s). Also check each contactor for
		proper high voltage input and output.
	50 Amp Fuses	If there is no high voltage input to the mercury
		contactor(s), check the 50 amp fuses and replace if
		necessary.
	Heater Elements	Check the Amp. draw on each hot leg for proper
		load. Check the specifications plate for rating
		information. If the Amp. draw is low or high, check
		the individual elements for opens, shorts, and
		proper resistance . To check resistance of the
		elements, turn off the power! Remove all leads
		from the elements and use an accurate digital
		VOM. The element resistance should be as
		follows: 208V - 9.8 ohms approx. 220V - 10.5 ohms
		approx. 240V - 13 ohms approx. If all readings are
		not correct, replace elements as needed.
Oven heats with switch	Mercury Contactor(s)	The mercury contactor has probably malfunctioned
off		in the closed position. If there is no voltage to the
		operating coil, but there is high voltage at the
		contactor output, replace the mercury contactor.
Conveyor will not run	Voltage Supply	Check incoming voltage supply at line 1 to neutral.
(S/N 100-4389)		There should be a voltage reading of 120 VAC. If
		not present, check breakers.
	3 Amp Fuse	This conveyor fuse is located on the front panel.
		Replace if defective.
	Fuse Holder	Check and/or Replace.
	Conveyor Switch	Same procedure as for fan switch.
	D. C. Motor Control Board	Check for 120 VAC input to D. C. control board
		across L1 and L2. Check the 3 amp fuse on the D.
		C. control board. Check for D. C. voltage at
		terminal F1 and F2. Voltage should be 10 VDC +
		10 steady. If this voltage is not present, replace D.
		C. control board. Check for D. C. voltage output to
		the motor across terminals A1 and A2 (this voltage
		should be approx. 125 VDC at maximum conveyor
		motor speed).

26 Impinger I -–1000 Series Service Manual - Domestic