AC Balance
Depress the “SET AC” button (4) twice. The balance light (4B)
will flash and the volts display will flash “b.AC”. While the
display is flashing, the AC balance will be displayed in the
“VOLTS”
digital display in %. Use the encoder (1) to adjust the
AC balance from 10% to 90% in 1 % increments while the
display is flashing.
A higher AC balance percentage gives you more electrode
negative, so you get more penetration, less cleaning, and your
tungsten runs cooler. A lower AC balance gives you more
electrode positive, which is more cleaning, less penetration,
but your tungsten runs hotter.
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Figure 12b
Chart 12d
Chart 12e
Chart 12C shows 60 Hz AC wave with the AC balance set to
50%. This is called a balanced square wave. The amount of
time the electrons flow from the torch to the work, and then
from the work to the torch, is equal.
Chart 12c
If you remember from the front panel connections, the ground
cable is in the positive output receptacle and the torch is in
the
negative. Chart 12D shows the AC balance set to 10%. For
10% of the time, the torch is negative and the electrons flow
from the torch to the work piece. The flow of electrons from
the torch to the work is the penetration cycle. The other 90%
of the time, the torch becomes positive and the work becomes
negative, and the electrons jump from the work to the tung-
sten. This flow of electrons from the work to the torch is the
cleaning cycle. The electrons literally blow the impurities off
the molten puddle. So when the AC Balance is set to 10% the
machine is set for maximum cleaning. You have to remem-
ber with the balance set this low, you are putting an extreme
amount of heat into your tungsten, and you will probably see
a 1/8” tungsten melt at less than 50 amps. One application
where you may want more cleaning (lower AC Balance) would
be if you were welding on a dirty casting.
Chart 12E shows the AC balance set to 90%. For 90% of the
time, the torch is negative and the electrons flow from the
torch to the work piece. The flow of electrons from the torch to
the work is the penetration cycle. The other 10% of the time,
the torch becomes positive and the work becomes negative,
and the electrons jump from the work to the tungsten. This
flow of electrons from the work to the torch is the cleaning
cycle. So when the AC Balance is set to 90% the machine is set
for maximum penetration. Higher AC balances put less heat
into the torch, and more heat into the work. An application
where you may want more penetration (higher AC Balance)
would be if you were trying to weld a heavier section than you
could normally weld with 220 amps – say something in the
3/8 to ½” range. Setting the balance to 90% may allow you to
make this weld, depending on the application. It is important
to note, that with less cleaning it is critical to clean the
piece properly.
4B
Figure 12B
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