Lincoln 1400 Manuel D’Utilisation

Impinger I -–1000 Series Service Manual - Domestic

TRANSFORMER (12.6

VAC)

Upon closure of the Fan Switch, 120 VAC is supplied to the primary of the 12.6 VAC

Transformer. The Transformer steps the voltage down to 12.6 VAC (normally 13 to

14 VAC) with a center tap, and supplies power to the Time/ Temp. Display. The

voltage from each leg of the Transformer's secondary to the center tap should be

one half of the secondary voltage.

BURNER CIRCUIT

Closing the Fan Switch and the normally open Burner Switch supplies 120 VAC

through the Air Pressure Switch, to the Temperature Control Board, the normally

open contacts of the Burner Motor Relay (Burner Motor Relay discontinued after S/N

14791) and the primary of the 24 VAC Transformer. The transformer's secondary

supplies 24 VAC to the burner motor relay coil (the normally open contacts close

within 30 seconds), and the normally open Centrifugal Switch. When the relay

contacts close, the Burner Blower Motor is energized. As this motor reaches approx.

1,600 R.P.M its internal centrifugal switch closes, supplying 24 VAC to the Gas

Control Valve. When the Gas Control Valve is supplied with 24 VAC, the pilot valve

is energized, and the igniter circuit is energized. Ignition should now occur. After pilot

flame is proven, the Main Gas Valve is energized. The Burner Indicator Light is also

energized.

TEMPERATURE

CONTROL

Closing the Fan Switch and Burner Switch supplies 120 VAC to the Temperature

Control Board. The 1K or 1000 ohm Temperature Potentiometer is adjusted to

desired temperature. The Thermocouple will provide varying millivolts to the

Temperature Controller. The Temperature Controller supplies 120 VAC to the

Solenoid Valve at intermittent intervals to maintain desired temperature.

CONVEYOR DRIVE

(S/N Q14790 & Below,

1200 series

S/N Q14973 & Below

1000 series)

(S/N Q14791 & Above,

1200 series refer to Pg.

5 & 6 S/N Q14974 &

Above, 1000 series refer

to Pg. 5 & 6 (STEPPER)

Closing the fan switch and the normally open conveyor Switch supplies 120 VAC to

the Motor Control Board. AC volts are converted to DC volts and are supplied to the

Conveyor Motor, at terminals A+ and A-. Adjustment of the Speed Control

Potentiometer (5,000 ohm 10 turn) will change resistance at terminals P1, P2, and

P3 varying the DC voltage to the Conveyor Motor. The speed of the conveyor motor

will increase or decrease as the DC voltage from the board increases or decreases

respectively. As the motor turns, it drives both the reducer gearbox and the tach.

generator. The tach. Generator is a DC voltage generator, which supplies a voltage

to the DC motor control board and is used as a reference for maintaining a constant

conveyor speed.

NOTE:

The 1200 Series Ovens utilize 2 complete conveyor drive systems.

TIME/TEMP

DISPLAY(S/N Q14790 &

Below, 1200 series

S/N Q14973 & Below

1000 series)

(S/N Q14791 & Above,

1200 series refer to Pg.

5 & 6 S/N Q14974 &

Above, 1000 series refer

to Pg. 5 & 6 (STEPPER)

The Time/Temp. Display is energized when the Fan Switch is closed, supplying 120

VAC to the primary of the12.6 volt Transformer. The secondary output of the

transformer, normally 13 to 14 VAC (depending on input), with a center tap, is

supplied to terminals 1,2, and 3 of the Time/Temp. Display. The center tap is

terminal 2. The display works on a balanced input and center tap voltage to each leg

must be 1/2 the total reading.

The speed side of the Time/Temp. Display uses a slotted disc (cemented to tach.

coupling) to break the infrared light beam of the optical switch (mounted on gear

motor) producing electrical pulses that are transmitted to the display. The display

converts these pulses into a read-out of minutes and seconds. The temperature

portion of the display uses a Thermistor Probe to sense oven temperature. The

thermistor outputs a resistance proportional to the oven temperature. This resistance

is then converted by the display into a temperature reading.

NOTE*

The 1200 Series Ovens use a Double Pole Double Throw Switch to connect the two

Optical Encoder Assemblies to the Time/Temp. Display. By activating the switch,

either the front or rear belt speed can be shown by the Time/Temp Display .

CONVEYOR DRIVE

Closing the Oven Fan Switch supplies 120 VAC, through the Power Transformer, to

the normally open Conveyor Switch. Closing the Conveyor Switch supplies 120 VAC,

through a 3 AMP Fuse, to the primary of the Conveyor Control Transformer. The

secondary of this Transformer supplies 10 VAC and 29 VAC to the Conveyor

Control. The conveyor control supplies voltage pulses to the Conveyor Control. The

Conveyor Control Potentiometer varies the frequency of these pulses. The motor

speed will increase or decrease, as the frequency of the pulses increase or decrease

respectively.