D5) TIG
REPEAT–
From the
TIG
Spot Mode, depressing the
welding mode (D) button once will put you in the “
TIG
Reset”
Mode. Using a TIG torch which has a trigger switch, the
TIG
Reset mode allows you to switch between 2 pre-programmed
welding amperages.
As shown in Fig 20, the “TIG REPEAT” light (D5) is illuminated
and the amps display will flash “riP” for
TIG
Repeat. When the
display stops flashing, the peak welding current will be
displayed in the “AMPS” digital display, and the welding voltage
will be displayed in the “VOLTS” digital display (00.0 unless you
are welding).
For example, you have your welding current set at 150 amps,
and your “FINAL CURRENT” set at 50% or 75 amps. Depress the
trigger and you have pre-gas flow for as long as you keep the
trigger depressed. Release the trigger and your TIG 221 will
begin to weld at 150 amps. Depress and release the trigger
and you will go to your final current of 75 amps. Depress and
release the trigger again and you will go back to 150 amps.
To stop welding, depress the trigger for 5 seconds or longer.
When the trigger is released the arc is extinguished and the
machine will go into post gas flow.
Welding parameters which can be adjusted using the
encoder
are slope down (2E), final current (2F), slope up
(2C), starting current (2B), pre-gas (2A), and post gas (2G).
E) HF ON – Depressing the “HF ON” button (E) so the green
light is illuminated turns the high frequency arc starting on.
When the foot pedal or torch trigger is depressed, a high
frequency arc will jump from the tungsten to the grounded
workpiece, initiating the arc. This makes it very easy to start
the arc, and also eliminates the possibility of tungsten contami-
nation from touching the work piece with the tungsten.
On your Invertig 221, in the AC mode, the high frequency is
only used to start the arc, unlike conventional transformer
welders which must have the high frequency on all the time
to maintain the arc.
When the high frequency is off, it is possible to do “lift arc”
starting. The lift arc mode allows you to initiate the welding arc
without high frequency. This is important in any environment
where the high frequency arc will cause interference with
sensitive electrical components or computers. A good
example of this would be stainless steel or aluminum repair
in hospitals. The Lift Arc mode works for both AC and DC
welding.
To TIG Weld using the Lift Arc Mode, simply touch the tungsten
to the workpiece, activate the torch trigger or depress the foot
pedal and lift off. When the tungsten breaks contact with the
work, the arc will start.
For Lift-Arc in aluminum, please remember the following
pointers to make arc ignition easier:
1) Keep the tungsten in contact with the workpiece for at
least 5 seconds before lifting off the work piece.
2) When using remote amperage control, it is advisable
to start the arc at a much higher amperage than the
actual welding amperage. Once the arc has been
established, reduce the amperage to the welding amperage.
3) For Lift Arc at lower amperages, the correct tungsten
(2%
Ceriated
) correct diameter, and a correctly
ground tungsten are very important.
4) A higher frequency (200 Hz) and higher balance (90%)
will make it easier to initiate your arc.
F) PUlSE ON – by depressing the “PULSE” button (F), the green
light will illuminate indicating your Invertig 221 is in the pulse
mode. At this time the “AMPS” display will show “P.Fr” for the
pulsing frequency. (See Fig 21)
Then a flashing number will come into the display which will
be the pulse frequency. While the number is flashing you can
adjust the pulse frequency using the encoder (1) from .4 PPS
(pulses per second) to 999 PPS in DC, and from .4 PPS to 10 PPS
in AC.
Depressing the “PULSE” button twice brings “P.du” into the
display. (See Fig 22) Then a flashing number will come into
the display which will be the pulse duty cycle or “peak welding
time” or just “peak time”. This is the percentage of the cycle
the machine will be welding at the “peak welding current”.
While the number is flashing you can adjust the peak time from
10% to 90% of the welding cycle in increments of 1%.
1
3
Figure 21
1
F
E
Figure 20
D5
D
2D
2G
2F
2E
2B
2A
2C
