Lincoln Electric TOMAHAWK 375 AIR Operator's Manual page 16

B-6
• Attach the work lead clamp to the workpiece before
cutting.
• Set the output current control knob to maximum
position for higher cutting speed and less dross for-
mation. Reduce the current, if desired to reduce the
kerf (cut) width, heat affected zone, or travel speed
as required.
Note: If the circuit breaker trips while cutting at high-
er amperages - reduce the cutting amperage
on the unit, or provide an input circuit with
higher current capacity.
• Rotate the output knob into the purge zone to check
or set the gas pressure. Pull the pressure regulator
cap out and turn it to set the pressure.
- Adjust the gas regulator for 75-80 PSI (0.50-0.55
MPa).
- Turn the output knob out of the purge zone.
- The gas will immediately turn off. The pressure
gage may show an increase in pressure after the
air turns off but this is normal. Do NOT reset the
pressure while the air is NOT flowing.
• When ready to cut, place the torch near the work,
make certain all safety precautions have been taken
and pull the trigger.
- The air will flow for a preflow time of 2 seconds
and the pilot arc will start. (Exceptions: the first
time that the trigger is pulled after the machine is
turned on, or after a thermal trip out, initial trigger
will be ignored. This is a safety feature to prevent
the pilot arc from firing unexpectedly or if the
torch trigger is inadvertently pressed. The other
exception is if the machine is in postflow, then
the preflow time is skipped and the pilot arc will
start immediately.)
- The pilot arc will run for 3.0 seconds and shut off
unless the arc is brought in contact with the work
and the arc is transferred. Avoid excessive pilot
arc time by transferring the arc to the workpiece
quickly. This will extend consumable life.
- When the arc is brought within 1/8" - 1/4" from
the work piece: the arc will transfer, the current
will ramp to the setting on the control panel, and
the cut can last indefinitely (or until the duty
cycle of the TOMAHAWK™ 375 AIR is exceed-
ed).
OPERATION
• Pierce the work piece by slowly lowering the torch
onto the metal at a 30
tor. This will blow the dross away from the torch
tip. Slowly rotate the torch to vertical position as
the arc becomes deeper.
• Keep moving while cutting. Cut at a steady speed
without pausing. Maintain the cutting speed so that
the arc lag is 10° to 20° behind the travel direction.
• Use a 5° - 15° leading angle in the direction of the cut.
• Finish the cut to be made and release the trigger.
• When the trigger is released, the arc will stop.
- The gas will continue to flow for 15 seconds of
postflow. If the trigger is activated within this time
period, the pilot arc will immediately restart.
• If the dross is difficult to remove, reduce the cutting
speed. High speed dross is more difficult to remove
than low speed dross.
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• Clean spatter and scale from the nozzle frequently.
TOMAHAWK™ 375 AIR
0 angle away from the opera-
0
TORCH AT 30 ANGLE
TO PIERCE
ROTATE TO
0
90 ANGLE TO CUT
0 0
30 30
0
90
VERTICAL VER TICAL ANGLE ANGLE
FOR CUTTING FOR CUTTING
CUT
5 - 15 Leading Angle
Direction of Travel
1/16"
10 - 20
Arc Lag
WARNING
ELECTRIC SHOCK CAN KILL.
• Turn off machine at the disconnect
switch on the rear of the machine
before tightening, cleaning or
replacing consumables.
B-6