Daihen Welbee WB-A350P, Owner'S Manual

Page: 83 / 150

6-23
Chapter 6 W
elding Condition
S
ETTINGS FOR
AC TIG W
ELDING AND
AC-DC TIG W
ELDING
W
ELDING
C
ONDITION
C
HAPTER
6
6.7.5
Setting AC-DC switchover frequency
Set the AC-DC switchover frequency for AC-DC TIG welding.
When either one of the initial condition, welding condition and crater condition is selected, press the AC-
DC SWITCHOVER FREQUENCY key. The upper left LED is illuminated and the set value is displayed
on the right digital meter with the Hz LED illuminated.
The AC-DC switchover frequency can be adjusted with the parameter adjustment knob in this condition.
Setting range is within 0.1 to 50 Hz.
Pressing the AC-DC SWEITCHOVER FREQUENCY key again or the PARAMETER SELECT keys
switches to the parameter setting just before the adjustment.
The relations between the AC-DC switchover frequency setting and the filler wire insertion interval are
as shown in the table below.
Insert filler wire manually or automatically.
The standard AC ratio is 70%. AC ratio is the ratio of AC period in one cycle of AC-DC period, expressed
by a percentage, and is defined by the following formula.
Also, the AC ratio can be changed by the internal function.
（
6.10.2.14 F14: AC ratio
）
When frequency is low AC-DC switchover frequency setting When frequency is high
When insertion interval is long. Filler wire insertion interval Insertion interval is short.
The ripple interval becomes long. Bead ripple Ripple interval becomes short.
Suitable for low-speed welding. Welding speed Suitable for high-speed welding
Manual insertion
When the AC-DC switchover frequency is 0.5 Hz to 2 Hz, the filler wire is inserted synchronized
with the AC period. Since the arc sound is large in the AC period and it is small in the DC period,
insert the filler wire using the change of the arc sound as a guide.
Automatic insertion
When inserting the filler wire automatically, set so that the filler wire is intermittently fed
synchronized with the AC period.
EP
（＋）
EN
（−）
DC period AC period AC period DC period
AC-DC switchover frequency (Hz) =
1
b (sec.)
a
b
AC ratio (%) = × 100
b
a