- 35 -
10. OPERATION (continued)
10.1.9 AC-DC Change-over Frequency Setup ( )
When the initial conditions, main conditions or crater filler conditions are being selected, press
the AC-DC change-over frequency setup key (
ԟ
), and the LED in the left upper part lights up,
the set point is displayed on the right-side digital meter, then the “Hz” LED lights up. In this
condition, it is possible to set up the AC-DC change-over frequency in AC-DC TIG welding,
using the parameter adjusting knob (
ԛ
). The setup range is 0.1Hz to 50Hz.
By pressing the AC-DC change-over frequency setup key again or the parameter selection
key (
Ԛ
), the system display screen returns to the parameter item in which the parameter was
adjusted to the value of one step ago.
The relationship between AC-DC change-over frequency setup and filler wire insertion interval is as
shown in the table below.
When frequency is low
㪘㪚㪄㪛㪚㩷㪚㪿㪸㫅㪾㪼㪄㫆㫍㪼㫉
㪝㫉㪼㫈㫌㪼㫅㪺㫐㩷㪪㪼㫋㫌㫇
㪮㪿㪼㫅㩷㫋㪿㫀㫊㩷㪽㫉㪼㫈㫌㪼㫅㪺㫐㩷㫀㫊㩷㪿㫀㪾㪿
The insertion interval is long.
㪝㫀㫃㫃㪼㫉㩷㫎㫀㫉㪼㩷㫀㫅㫊㪼㫉㫋㫀㫆㫅㩷㫀㫅㫋㪼㫉㫍㪸㫃
㪫㪿㪼㩷㫀㫅㫊㪼㫉㫋㫀㫆㫅㩷㫀㫅㫋㪼㫉㫍㪸㫃㩷㫀㫊㩷㫊㪿㫆㫉㫋㪅
The ripple spacing becomes
wide.
㪙㪼㪸㪻㩷㫉㫀㫇㫇㫃㪼
㪫㪿㪼㩷㫉㫀㫇㫇㫃㪼㩷㫊㫇㪸㪺㫀㫅㪾㩷㪹㪼㪺㫆㫄㪼㫊
㫅㪸㫉㫉㫆㫎㪅
For low-speed welding
㪮㪼㫃㪻㫀㫅㪾㩷㫊㫇㪼㪼㪻
㪝㫆㫉㩷㪿㫀㪾㪿㪄㫊㫇㪼㪼㪻㩷㫎㪼㫃㪻㫀㫅㪾
(1) Manual insertion
In case where the AC-DC change-over frequency is 0.5Hz to 2Hz, insert a filler wire in
synchronism with AC period. Since the arc sound becomes large during AC period and it becomes
small during DC period, insert this filler wire with changes in arc sound as a guide.
(2) Automatic insertion
In case where a filler wire is inserted automatically, set it so that it is fed intermittently in
synchronism with the AC period.
The standard AC ratio is 70%. The AC ratio is such that the rate of AC period to one cycle of AC-
DC is represented in “%”, which is defined by:
AC ratio (%) = a/b
×
100
Also, this AC ratio can be changed by using the internal function. For details, refer to “10.1.17:
Internal Function”.
f
㧱㧺㧔㧙㧕
㧭㧯ᦼ㑆
㨍
㨎
㧱㧼㧔㧗㧕
㧰㧯ᦼ㑆
㧰㧯ᦼ㑆
㧭㧯ᦼ㑆
DC period
AC period
AC-DC change-over frequency (Hz)
1
=
̆̆̆̆
b (sec)
DC period
AC period