Pulse Frequency; Tig Ac (Only Item No 558); Ac Settings (Sector U) - Cebora 553 Manuel D'instructions

5.5.1

Pulse frequency

Pulse frequency
0.1 Hz - 10 Hz
10 Hz – 2.5 kHz
5.6

TIG AC (only Item No 558)

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).
5.6.1

AC settings (SECTOR U)

Based on the AC process selected in the U-sector of the main screen, the icons corresponding to the related welding
parameters will appear. Select and confirm U sector to access adjustment of the welding parameters as in Table 5.
Table 5 - AC PROCESS PARAMETERS SETTING
Process
TIG AC
TIG
AC+DC
68/89
Wide welding bead with evident
overlap, easy arc control
Narrow welding bead with not
very evident overlap, high welding
stability and speed.
Description
Balancing AC
Frequency AC
Balancing AC
Frequency AC
Duty Cycle
Min. Def Max
EP 8 EP-8
0.0
EN-8 EN 8
50 90 200
EP 8 EP-8
0.0
EN-8 EN 8
50 90 200
20 50 90
UM Res.
-
1
Hz
1
-
1
Hz
1
% 1
3301230/A