Lincoln Electric SQUARE WAVE TIG 355 Service Manual page 63

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Observe Safety Guidelines detailed in the beginning of this manual.
PROBLEMS
(SYMPTOMS)
The Pulsar does not seem to oper-
ate.
The Spot Timer does not last as
long as the nameplate setting.
The Spot Timer lasts much longer
than the nameplate setting.
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 1-888-935-3877.
TROUBLESHOOTING AND REPAIR
POSSIBLE AREAS OF
MISADJUSTMENT(S)
FUNCTION PROBLEMS
1. If the Start controls are used,
pulsing does not begin until the
end of the "start" time, which can
be as much as 10 seconds.
2. Check the Pulses Per Second
control. If it is set near minimum,
each pulse may be as long as
ten seconds. Set all three of the
pulse controls near the midpoints
to see the pulser's effects.
3. The Pulse % On control may be
set at either extreme. If that is
the case, the pulses may be too
short to be seen.
1. When in the 2-Step trigger mode,
be sure to keep the Arc Start
switch or Amptrol pressed until
the spot time is completed.
Releasing the Arc Start switch
before the Spot Timer has timed
out will cause the arc to go out.
1. Make sure the Crater Fill switch
is turned off. If it is on, the actu-
al weld time will be the spot time
plus the crater fill time.
CAUTION
SQUARE WAVE TIG 355
RECOMMENDED
COURSE OF ACTION
1. Check the Pulse controls (R18,
R19 and R20) for correct resis-
tance and proper operation.
See Wiring Diagram.
2. The control board may be faulty.
Replace.
1. Check the Spot Timer control
potentiometer (R16) for correct
resistance and proper opera-
tion.
2. The control board may be faulty.
Replace.
1. Check the Spot Timer control
potentiometer (R16) for correct
resistance and proper opera-
tion.
2. The control board may be faulty.
Replace.
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