Lincoln Electric NA-5N Service Manual page 59

F-6
Observe all Safety Guidelines detailed throughout this manual
PROBLEMS
(SYMPTOMS)
The wire will not feed and the circuit
breaker (CB1) trips when the inch
down, inch up or the start buttons
are pressed. The wire drive motor
does not turn.
When the inch up button is press the
wire feeds down. When the inch
down button is pressed the wire
feeds up.
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 & REPAIR
POSSIBLE AREAS OF
MISADJUSTMENTS(S)
WIRE FEEDING PROBLEMS
1. Check for a mechanical restric-
tion in the wire feeding path.
2. Make sure the proper input volt-
age (115VAC) is applied to the
NA-5 control unit.
3. Check the F102 field fuse on the
power board. Replace if faulty.
Note: Frequent motor polarity
changes can cause the fuse to
fail. This can be caused by the
following:
•A welding procedure with
frequent electrode to puddle
shorting.
•A power source output too
low to establish an arc.
1. The welding head is designed to
feed wire in the proper direction
when it is installed as shipped
from the factory. If the nozzle
and wire straightener aare rotated
about the axis of the gearbox
outpu shaft, the wire may feed in
the opposite direction.
Interchange leads #626 and #627
at the terminal strip (TS2) inside
the control box. See wiring dia-
gram.
CAUTION
NA-5
RECOMMENDED
COURSE OF ACTION
1. Perform the Wire Drive Motor
Test.
2. The power board may be faulty.
See Table F.1.
3. Check the motor control cable for
"shorts' or "grounds".
F-6