Design and function
TIG welding
099-005542-EW501
24.03.2020
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5.4.6 Arc ignition
5.4.6.1 Liftarc
Figure 5-42
The arc ignites through contact with the workpiece:
a) Carefully place the torch gas nozzle and tungsten electrode tip against the workpiece (lift arc current
flows independent of the set main current)
b) Angle the torch above the torch gas nozzle until the distance between electrode tip and workpiece is
approx. 2–3 mm (arc ignites, current increases to the set main current).
c) Lift the torch off and bring into normal position.
Complete the welding task: Remove the torch from the workpiece so that the arc extinguishes.
5.4.7 Operating modes (functional sequences)
5.4.7.1 Legend
Symbol Meaning
Press torch trigger
Release torch trigger
I
Welding current
Gas pre-flows
Gas post-flows
Non-latched
Latched
t
Time
t
Up
Upslope time
t
Down
Downslope time
I
start
Ignition current
I
end
End-crater current
5.4.7.2 Automatic cut-out
Once the fault periods have elapsed, the automatic cut-out stops the welding process when it has been
triggered by one of two states:
• During ignition
5 s after the start of the welding process, no welding current flows (ignition error).
• During welding
The arc is interrupted for more than 5 s (arc interruption).
