Lincoln Impringer Conveyor Oven 1200 - Manual (Page 41)

Impinger I -–1000 Series Service Manual - International 41
Speed Control Potentiometer This is a 0 to 400 ohm or 0 to 500 ohm, 10-turn
potentiometer. WITH POWER OFF: remove the
red, white, and black leads from terminals S1, S2,
S3. With a digital multimeter, check the ohm
reading across the red to black leads. This ohm
reading should be a steady 400-ohm, or 500-ohm,
through the entire 10-turn rotation of the
potentiometer. Check for shorts or opens or
unsteady, ohms reading, if potentiometer is
defective, replace. If the potentiometer checks OK,
and there is no output at terminals A1 and A2,
replace the D. C. control board.
Reversing Switch If there is D. C. voltage output from the motor
control board, but the conveyor drive motor is not
running, check the D.P.D.T. reversing switch.
Conveyor Drive Motor Check the conveyor drive sprocket for tightness.
Disconnect the motor, check the red and black
motor leads for opens, shorts or grounds. Check
the brushes for excessive or abnormal wear.
Replace as needed. Reconnect motor. Test for
operation. If motor does not run, replace.
Voltage Supply Check incoming voltage supply at line 1 to neutral.
There should be a voltage reading of 120 VAC. If
no present, check breakers. 3 Amp Fuse. This
conveyor fuse is located on the front panel.
Replace if defective.
Fuseholder Check and/or Replace.
Fan Switch See procedure for checking on Page 26.
Conveyor will not
run(S/N 4390 to
Q190771000 Series)
(S/N 4390-
Q147901200 Series)
Conveyor Switch Same procedure as for fan switch.
NOTE: (Dual Belt Ovens) Dual belt ovens utilize 2 complete independent
conveyor drive systems. The trouble shooting
procedures are the same as single belt ovens,
except that the dual belt ovens use one each of the
following: one "A" D. C. control board and one "B"
D. C. control board.
Speed Adjustment
Potentiometer
This is a 0 to 5 K ohm, 10 turn potentiometer With
power off, remove the red, black and white pot
leads from the motor control board at terminals P1,
P2 and P3. With a digital multimeter, check the
ohm reading across the red lead (P3) to the black
lead (P1). This reading should be 5 K ohms ± 5%
as the pot is rotated from low to high. Place the
meter leads on the red lead (P3) and on the white
lead (P2) Rotating the pot. slowly, from low to high,
the meter reading should show an even transition
from O to 5 K ohms ± 5%. There should be
no dead or open spots through out the 10 turns of
the pot. Check all three leads to ground. There
should be no continuity to ground. If any of the
above checks fail, replace the pot.