Lincoln Impringer Conveyor Oven 1200 - Manual (Page 6)

Impinger I -–1000 Series Service Manual - International 6
CONVEYOR DRIVE
(S/N 100 to 4389) Closing the Fan Switch and the normally open Conveyor Switch supplies 120 VAC
through a 3A Fuse, to the Motor Control Board. AC volts are converted to D.C. volts
and are supplied to the Conveyor Motor at board terminals A1 and A2 through a
D.P.D.T. Reversing Switch. Adjustment of the Speed Control Potentiometer (500
ohm, 10 turn) will change resistance at terminals S1, S2, and S3 varying the D.C.
voltage to the Conveyor Motor. The speed of the Conveyor Motor will increase or
decrease as the D.C. voltage from the Motor Control Board increases or decreases
respectively.
(S/N 4390 and UP
1000 Series)
(S/N 4390 to 14790
1200 Series)
(S/N 14791 & Above
1200 Series
See Page 9 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 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 4390 &
Above1000 Series) S/N
4390-147901200 Series)
(T/T Display S/N
Q14791& Above1200
Series See Page 9 The Time/Temp. Display is energized when the Fan Switch is closed, supplying 120
VAC to the primary of the 12.6 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 infra-red 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.
SEQUENCE OF OPERATIONS 1030
MODEL 1030 - 220 VAC - 50HZ - 1 PHASE
POWER SUPPLY Electrical Power to be supplied to the Oven by a three conductor service.
Black conductor is Hot
Red conductor is Neutra
Green conductor is Ground
CONTROL BOX
AUTO COOL DOWN When the temperature in the Control Box reaches 120°F + 3°, the Cooling Fan
Thermostat will switch power to the Control Box Cooling Fan. The Thermostat will
interrupt power to the Cooling Fan when the Control Box temperature falls to 100°F +
3°.
MAIN FAN CIRCUIT Electrical power is permanently supplied to the normally open contacts of the Double
Pole Main Fan Relay, the Cooling Fan Thermostat, the normally open Main Fan
Switch, and the normally open Cool Down Thermostat (thermostat closes at 160°F
and opens at 140°F). Closing the Main Fan Switch supplies 220 VAC through a 3A
Fuse to the (normally open) Burner Switch, and to the control circuit Step Down
Transformer (the transformer steps the voltage down to 120 VAC for the control
circuit) 120 VAC is supplied to the coil of the Main Fan Relay The coil is energized,
the normally open contacts close, supplying 220 VAC through one 10A Fuse to the
Main Fan Motor. 120 VAC is also supplied to the 12.6 VAC Transformer, the
Temperature Controller and the Conveyor Switch.
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