Lincoln Countertop Impinger, Service Manual

Page: 44 / 64

CounterTop – 1300 Series Service Manual 44
Fan Switch WITH POWER OFF: Check continuity between switch
terminals. Check and insure good wire connections.
Conveyor Control
Transformer With the fan switch on, check for supply voltage at the
primary of the transformer. Check for voltage on the
secondary side of transformer (24 VAC) at J4 and J5 on
the conveyor control board. Replace as needed.
Speed Adjustment Pot This is a 50 K ohm potentiometer. WITH POWER OFF:
Remove the leads from the motor control board at
terminals P1, P2, P3. With a digital meter, check the
ohm reading across the red and black leads. This
reading should be 50K ohms (± 10%) as the pot. is
rotated from low to high. Place meter leads on red and
white lead. Rotating the pot. slowly from low to high, the
meter reading should show an even transition from 0 to
50 K ohms (±10%). There should be no dead or opens
spots throughout the rotation of the pot. Check all three
(3) leads to ground. There should be no continuity to
ground. If any of the above checks fail, replace the pot.
Conveyor Control
Board Check for 24 VAC input to the control board at terminals
J4 and J5. If not present, check wiring back to control
transformer, if voltage is present at J4 and J5, check the
VDC output at terminals J2 (+) & J3 (-) (0-18 VDC). If
24 VAC is present at J4 and J5, but VDC is not present
at J2(+) & J3(-) replace board.
Conveyor Gear Motor If D.C. voltage is present at J2(+) and J3(-) and the
motor does not run, first check the mini breaker (.7Amp).
Check the leads to the motor for evidence of any shorts
or opens, and each lead to ground. If the motor fails the
above tests, replace motor.
Conveyor will not run
(S/N 3000481 & Above)
Conveyor Check for any mechanical misalignment or improper
adjustment, also check for worn bearings. A conveyor
belt that is too tight will cause excessive bearing wear
and sometimes, irregular speed.
Power Supply Check for steady supply voltage to oven. If voltage is
unsteady, contact Power Company.
Transformer Check for steady AC voltage output from transformer
and replace as needed.
Conveyor Control Check for steady D.C. voltage output from conveyor
control. If D.C. voltage output is unsteady, check
conveyor potentiometer (See Speed Adjustment
Potentiometer" under Conveyor will not run). If the
potentiometer checks good, and the D.C. voltage is
unsteady, replace conveyor control.
D.C. Gearmotor Check motor brushes for excessive arching and/or
unusual wear. Replace brushes or gearmotor as
needed
Magnet Check to insure that the magnet (cemented to shaft of
conveyor drive motor) has not been damaged, or come
loose from motor shaft. Replace as needed.
Conveyor speed
varying or intermittent
Hall Effect Sensor Check for any physical damage to Hall Effect Sensor
(mounted on conveyor motor). Check all wiring and
connections or damage. Check all connections for
tightness or proper location and check all wiring or
visible damage. Replace as needed.