Lincoln 1200 Convection Oven User Manual


 
Impinger I -–1000 Series Service Manual - Domestic
28
Conveyor Gear Motor If DC voltage is present at A+ and A- and the motor
does not run, first check the mini breaker and then
the conveyor. Refer to the next possible cause.
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. Remove
dust cover from the top of the motor and rotate
motor shaft to determine if there is a locked rotor or
a locked gear box (use care so encoder disc is not
damaged).
Conveyor Check for any mechanical misalignment or
improper adjustment. Also check for worn
bearings. The Installation and Operations Manual
shows proper conveyor belt adjustment. A
conveyor belt that is over tightened will cause
excessive bearing wear and sometimes, irregular
speed.
Power Supply Check power supply at the DC control board for the
120 VAC at board terminals L1 and L2. If voltage is
not present, check main circuit breakers.
Tach generator and DC Motor
Control Board
With the power to the DC motor control board
turned off, remove the leads from terminals T1 and
T2.Place the test leads of a digital meter on the
tach leads, turn power on, and the meter reading
should be approximately 30 to 35 VDC. This
reading should be steady within ± 0.2 to 0.3 VDC.
If this reading is not within + 0.5 VDC, place the
test meter probes on terminals A+ and A-. The
meter reading should be approximately 150 to 160
VDC and steady within approximately 2 VDC. If the
tach. voltage is unsteady, and the board output is
steady, check the coupling for loose set screws or
any type of damage. If the coupling checks good,
the tach. is usually bad. If the board voltage output
is unsteady beyond limits, then the board is
probably bad. Always check the speed pot. Be sure
it is okay before changing a board or tach. This test
is not always 100% accurate as this test is not
performed at operating speeds. However, this test
is the best method currently available.
Readjustment should always be attempted at least
once before replacement. See procedure for board
adjustment on page 44.
Conveyor speed
varying or intermittent
DC Gearmotor If the DC control board is steady then the problem
may be the motor or gearbox. Check the brushes
in the motor for excessive arching and/or unusual
wear. Check the motor and gearbox from
instruction located on page 27 under "possible
cause" listing "Conveyor gear motor".
Voltage Supply Check incoming voltage supply at Line 1 to neutral.
There should be a voltage reading of 120 VAC.
Fan Switch See procedure for checking on page 20.
Conveyor Switch Check for 120 VAC to conveyor switch. If no
voltage is present, trace wiring back to the fan
switch. WITH POWER OFF: Check continuity
between switch terminals.
Conveyor Fuse (3A) Check, replace if necessary.
Conveyor will not
run(S/N Q19078 &
Up1000 Series) (S/N
Q14791 & Up1200
Series)
Fuseholder Check, replace if necessary.