Lincoln Electric IM467 SQUARE WAVE TIG 355 - Manual (Page 44)

TROUBLESHOOTING
E-5 E-5
SQUARE WAVE TIG 355
TROUBLESHOOTING GUIDE Observe Safety Guidelines
detailed throughout this manual.
SYMPTOM CAUSE AND REMEDY
Tungsten is eroding quickly. 1. Current potentiometer is set too high for tungsten size.
Reduce welding current or increase tungsten size.
2. In AC, Wave Balance control may be set too far towards
CLEANING. Turn Balance pot towards PENETRATION, or
increase tungsten size.
Tungsten seems to “spit” when Arc Start Switch High welding current is thermally “shocking” the cold
or Amptrol is pressed at high currents. tungsten causing pieces of the end to spall off. Turn Start
Switch ON, and set Start Current to a value lower than the
welding current to give a “soft” start.
TIG WELDING (Continued)
LOWER PANEL CONTROLS
SYMPTOM CAUSE AND REMEDY
Machine does not always wait for Preflow time Machine is operating correctly; it does not go through a
when starting arc. Preflow period if the Arc Start Switch or Amptrol is pressed
during the Afterflow period.
The Spot Time does not last as long as the When in the 2-Step mode, be sure to keep the Arc Start Switch or
nameplate setting. 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.
The Spot Time lasts much longer than the The Crater Fill switch should be turned OFF. If it is left ON,
nameplate setting. the actual weld time will be the spot time plus the crater fill time.
The Start Current seems very hot. The Start Current dial is labeled MIN to MAX of the welder
output or, 2 to 400 amps. Always be sure to use the Start Read
pushbutton to check the Start Current preset reading on the digital
ammeter before welding.
The Pulser does not seem to operate. 1. If 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 mini-
mum, 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, depend-
ing on the settings of the Current and Background % Current
controls. Set all three of the pulse controls near the mid-
points to see the Pulser’s effects.
When using Crater Fill, the arc goes out 1. The Crater Fill % Current control may be set too low for the
before the final Crater Fill Current level tungsten being used. Increase the Crater Fill % Current con-
is reached. trol until the final Crater Fill current is within the tungsten’s
operating range.
2. If using the Pulser in conjunction with the Crater Fill, the
Background % Current may be too low for the tungsten as
the current is downsloping in Crater Fill. The best solution is
to increase the Background % Current level.
3. If welding with AC use CONTINUOUS High Frequency. The
high frequency will stabilize the arc as the current goes
down.