Tig Ac - Cebora ARCO Manual De Instrucciones

7

TIG AC

AC welding is used to weld aluminium and aluminium alloys. The procedure involves continuous changes in the
polarity of the tungsten electrode. Two phases are available (half-waves): a positive phase and a negative phase. The
positive phase causes the aluminium oxide layer on the surface of the material to break down (cleaning effect), while
at the same time a cap forms on the tungsten electrode tip. The size of this cap depends on the length of the positive
phase. It should be noted that an over-large cap leads to a diffuse and unstable arc with reduced penetration. The
negative phase cools the tungsten electrode while generating the necessary penetration. It is important to choose the
correct time ratio (balance) between the positive phase (cleaning effect, cap size) and the negative phase (penetration
depth). This requires the AC balance to be set. The factory setting is a zero balance.
To activate the welding process, press pushbutton Q - Fig� 4 on the main screen and then select AC using encoder B�
This process is not supported by TIG DC power sources Items 380, 381.
The TIG AC process parameters are set by following the pathway Menu -> Process Parameters: see table 1.
The AC process parameters can be selected from section V – Fig� 4�
In section N turn knob B to select the parameter to be modified, press the required parameter and adjust the value
by turning encoder B� Once the change has been made, press B to confirm. The parameter can be modified when
it turns red.
From the main menu, select pushbutton V – Fig� 4, to set the parameters
of the TIG AC process�
NOTICE
Description
AC Balance.
Adjust the percentage penetration
in relation to the cleaning phase.
The longer the cleaning phase, the
more the electrode is rounded.
AC Frequency.
Frequency of the
output current
AC Amplitude Adjust
Adjusting the penetration
peak and cleaning allow an
improvement in wear and
electrode rounding.
Min DEF
-10 0
50 90
alternating
-80 0
Max UM Sol�
10 s 0.1
200 Hz 1
80 % 1
75/107