Lincoln Electric NA-3 Service Manual page 76

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Troubleshooting Guide –
of specified components and when troubleshooting specific circuits.
PROBLEMS
(SYMPTOMS)
The wire feeds up instead of down
when the "Start" switch is pressed.
There is no voltage reading on
NA-3/NA-4 voltmeter. The wire
inches up and down properly.
If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely,
contact the Lincoln Electric Service Department for technical troubleshooting assistance before you proceed.
Call 216-383-2531 or 1-800-833-9353.
TROUBLESHOOTING AND REPAIR
See the Wiring Diagrams Section for location
POSSIBLE AREAS OF
MISADJUSTMENT(S)
FUNCTION PROBLEMS (Continued)
1. Check for proper connection of
electrode leads and control
cable leads from power source
to NA-3/NA-4.
2. On Lincoln Electric power
sources, put a jumper from
leads #2 to #4 on the terminal
strip. This activates the output
from the power source. Test
for voltage at the output termi-
nals of the power source. If no
voltage is indicated, the power
source is faulty.
3. If voltage is present at the
power source output terminals,
it should also be present at the
NA-3/NA-4 voltmeter. If not,
check leads #21 and #67 for
breaks or faulty connections.
CAUTION
NA-3 AND NA-4
Observe Safety Guidelines
detailed at the beginning of this manual.
RECOMMENDED
COURSE OF ACTION
1. Check lead #21 for continuity
(zero ohms) to "work".
2. Check lead #67 for continuity
(zero ohms) to electrode.
3. Check lead #690 on the logic
board for proper connection.
See wiring diagram.
4. Check leads #2 and #4 for
loose or faulty connections
between relay 1CR and the
control cable receptacle.
5. Remove electrode from drive
rolls and press the "Start"
switch. Observe light 2K on the
logic board. It should be lit. If
light 2K does NOT light when
the "Start" switch is pressed,
remove power to unit. Remove
lead #682 from relay 3CR.
Check the resistance of the
coil from that terminal on the
relay to lead #510. Normal
resistance is approximately
10,000 ohms. See wiring
diagram.
6. If the relay coil resistance is
correct, the logic board may be
faulty.
7. If light 2K does light, make
sure relay 3CR contacts are
making electrical contact.
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