Lincoln Electric IM422 PRO-CUT 40 - Manual (Page 11)

time period, the pilot arc will immediately restart.
H. If the “Safety” LED lights at any time, check the following:
• Check the torch consumables. If they are not
properly in place the machine will not start.
• Check the condition of the inside of the
nozzle. If debris has collected, scrape it out
with a piece of sturdy wire or a suitable drill bit.
Refer to “Suggestions for Extra Utility from the
PRO-CUT system”.
• After the problem is found, reset the machine
by pressing the “Safety Reset” button. (It is
possible for electrical noise to trip the safety
circuit on rare occasions. This should not be
a regular occurrence.)
• If the machine does not reset or continues to
trip, consult the Troubleshooting Section.
Pilot Arc Discussion:
The PRO-CUT 40 has a smooth, continuous pilot arc.
The pilot arc is only a means of transferring the arc to
the workpiece for cutting. Repeated pilot arc starts, in
rapid succession, is not recommended. These starts
will generally reduce consumable life. Occasionally,
the pilot arc may sputter or start intermittently. This is
aggravated when the consumables are worn or the air
pressure is too high. Keep in mind that the pilot arc is
designed to transfer the arc to the workpiece and not
for numerous starts without cutting.
Procedure Recommendations
When used properly, plasma arc cutting is a very eco-
nomical process. Improper use will result in a very
high operating cost.
General
• Follow safety precautions as printed inside the
operating manual and on the machine.
• The S19425-1 Drag Cup is recommended when
the output control is set in the blue range to pro-
tect the torch from dross and improper arcing
conditions.
• Use proper cutting procedures referred to in
the Procedures Guidelines.
Thin Gauge Sheet Metal:
Output set below mid-range.
• The torch should be dragged on the metal sur-
face, touching the nozzle lightly to the surface
after piercing a hole. Current control should be
set in the yellow range only.
• The S19425-1 Drag Cup should not be used at
very low outputs, as it will cause erratic arc
action.
• Do not allow the torch cable or body to contact
hot surfaces.
• The best cut quality is obtained by reducing the
current to a level that is adequate for the maxi-
mum travel speed.
• Aluminum, copper and other nonferrous metals
typically require more current than the same
thickness of steel.
Expanded Metal:
Output set near mid-range.
• Cut as you would light gauge sheet metal.
• If the trigger is continuously pressed and
released to obtain the bright pilot arc for long
periods of time, the machine will go into pilot arc
duty cycle limit. This is a 30 seconds out of 60
seconds pilot duty cycle. The pilot arc is dis-
abled in the limit period. Pilot arc duty cycle
limit is indicated by alternately flashing “OUT-
PUT ON” and “FAULT” LED’s.
• Placing a thin piece of scrap sheet metal above
the area to be cut and cutting through both can
make the job easier.
• Do not allow the torch cable or body to contact
hot surfaces.
– 11 –
WARNING
ELECTRIC SHOCK CAN KILL.
• Turn off machine at the disconnect
switch at the back of the machine
before tightening, cleaning or replac
ing consumables.
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