Lincoln 1100 Series Service Manual page 27

S/N 21011383 and
above Models 1130
through 1133 –
2011978 and above
Models 1160 through
1163 – Refer to page
29
Time/Temp Display
inoperative S/N
2011383 and above
Models 1130 through
1133 Refer to Page 29
Temp Display out or
inaccurate
From S/N 2011383
and up Models 1130
through 1133 S/N
2011978 and up
Models1160
through1163 Refer to
Page 29
Impinger II –1100 Series Service Manual - Domestic
Tach. generator and DC
Motor Control Board
DC Gearmotor
12.6 VAC Power Supply
NOTE: Time/Temp displays
use two types of temperature
sensors thermistor probe-2
yellow wires, thermocouple
probe-1 red wire and 1 white
wire
Thermistor Probe
breakers and call power company if necessary.
WITH POWER OFF: Remove the leads from terminals
T1 and T2. Place the test leads of a digital test meter
on the tach. leads, turn power on, and the meter
reading should be approximately 20 to 25 VDC. This
reading is normally steady within
this reading is not within required 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 4 to 5 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 41.
If the problem seems to 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 26 under "possible
cause" listing "Conveyor gear motor".
Measure the transformer primary for a nominal 120
VAC input. Measure the secondary voltage output
which will be 12.5 to 15 VAC normally. Recheck
secondary output at rear of Time/Temp Display.
Terminals 1 to 3 should read 12.5 to 15 VAC.
Terminals 1 to 2 and 2 to 3 should be 1/2 of the
reading across 1 to 3. If you do not get the above
secondary readings, replace the transformer. If 120
VAC primary voltage is not available, refer to the
schematic and trace circuit for incoming power failure.
The older units have a 4 amp ambient fuse in each red
secondary lead. These may be jumpered to
determine if they are burnt out or intermittent.
Insert the thermocouple of your pyrometer into a finger
hole in the top center of the oven. Be sure the tip of
the thermocouple is not touching metal. The
pyrometer will indicate oven temperature.
Disconnect the yellow tipped thermistor leads from the
time/temp. terminals 9 and 10. Measure the resistance
of the thermistor probe and temperature of oven. See
the chart on page 44 for proper resistance readings.
Inspect the thermistor bulb for its proper location in its
spring holder. Check for short in leads where they
enter the sensor bulb. Also check each thermistor lead
for short to ground.
0.2 to 0.3 VDC. If
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