WELD THE WORLD
Cod. 006.0001.0340
15/04/2021 V.2.13
Discovery 200AC/DC
19
ENGLISH
set as a percentage of the welding current or as an absolute value expressed in Amperes. The
parameter is displayed but it is not used during the welding process when the following setting is
present: MULTI TACK = ON The usefulness of having an adjustable initial welding current is that
of avoiding welding the part with excessively high current values and thus potentially damaging it.
Particularly useful when welding thin sheets.
- AC INVERSION FREQUENCY
○ The frequency in TIG AC is the number of inversions by DC + to DC- as a unit of time (T1) and
adjusted in Hertz (Hz). The reduction in the frequency value of the electric arc inversion tends to
widen its size, therefore it is advisable to use low frequencies for the welding of relatively large
thicknesses or for filling passes in multipass bevels. Conversely, in increasing the inversion fre
-
quency value, the arc size tends to decrease and therefore increases the concentration of the
pool and the precision of the welding. It is therefore advisable to use high values of frequency for
the welding of very thin thickness or for facings on edges of moulds
-
Consequences of a higher value:
• Arc concentration.
•
Reduction of heat-affected zone.
•
Slower melt speed.
INVERSION FREQUENCY
LOW FREQUENCY
(s)
T1(s)
T1 (s)
HIGH FREQUENCY
(s)
T1 (s)
- AC BALANCE
○ This parameter establishes the positive wave vs. negative wave time ratio.
The following figure shows graphs with waves with different AC balance values: “0” BALANCE
represents the optimum ratio between “Cleanliness and Penetration”. “+” BALANCE represents
the curve of the current curve with an AC Balance with a positive value (cleaner); in this case the
percentage of the positive wave is greater than the negative one. “-” BALANCE represents the
curve of the current with a negative value AC balance (more penetration) in which it can be seen
that there is a low percentage of positive wave when compared with the negative.
-
Consequences of a higher value:
•
Greater weld penetration.
• Less cleanliness.
