SET-UP, OPERATION & TROUBLSHOOTING
17
4.2 Argon Arc Welding Operation
4.2.1 TIG welding
（
4T operation
）
The START and END current and can be pre-set to compensate for crater that
appears at the beginning and end of the welding making 4T ideal for aluminum and
medium thickness plates.
Process
：
0
：
Press down and hold the pedal switch, gas valve is opened.
0
～
t1
：
Pre-gas flows at preset time (0.1~1S);
t1
～
t2
：
Arc is ignited at
t1
and output is at preset value of start current;
t2
：
Release pedal switch, the output current slopes up from the start current;
t2
～
t3
：
The output current rises to the setting value (Iw or Ib), per upslope time set;
t3
～
t4
：
Welding process. During this period, the pedal switch is UP;
Note: Select the pulsed output, the base current and welding current will be outputted
alternately; otherwise, output the setting value of welding current;
t4
：
Press the pedal switch DOWN and the welding current will drop per the selected
down-slope time to end current setting;
t4
～
t5
：
The output current slopes down to the end crater current setting
t5
～
t6
：
The crater current time (controlled by pedal);
t6
：
Release pedal switch to stop arc but keep shield gas flowing;
t6
～
t7
：
Post-gas time
（
0.1
～
10S
）
until valve closes;
t7
：
Gas valve is closed and welding process is finished.
