Lincoln Electric NA-3 Service Manual page 71

F-6
Troubleshooting Guide –
of specified components and when troubleshooting specific circuits.
PROBLEMS
(SYMPTOMS)
The wire will not feed and circuit
breaker trips when "Inch" or "Start"
switches are pressed.
The wire will not feed when
"Start" switch is pressed. There
is not a voltage indicated on the
NA-3/NA-4 voltmeter. Wire does
inch 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. Reset the circuit breaker and
observe lights 1C and 1D on
the control board with the unit
at idle (not attempting to feed
wire). Light 1C should be
"Off" and light 1D should be
"On". If both lights are "Off"
remove power and check field
fuse F101 (1/2 Amp).
2. If both lights are "On", the
control board may be faulty.
3. The following conditions may
cause fuse F101 to fail.
-Faulty wire drive motor
-Incorrect welding procedure.
-A low impedance across the
arc voltage sensing leads #21
and #67.
-A defective control board.
1. If light 2B is on when the
"Start" switch is pressed, the
logic board may be faulty.
CAUTION
NA-3 AND NA-4
Observe Safety Guidelines
detailed at the beginning of this manual.
RECOMMENDED
COURSE OF ACTION
1. If when at idle light 1D is "On"
and light 1C is "Off", then
perform the Wire Feed Drive
Motor Test.
1. While pressing the "Start"
switch, observe light 2B. It
should be lit. If not, the "Start"
switch (S5) or associated
wires may be faulty. See
wiring diagram.
F-6