Design and function
Voltage reducing device
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099-002050-BOC01
30.11.2009
5.7.3
TIG arc ignition
a)
b)
c)
Figure 5-5
The arc is ignited on contact with the workpiece:
a) Carefully place the torch gas nozzle and tungsten electrode tip onto the workpiece (liftarc current
flowing, regardless of the main current set).
b) Incline the torch towards the torch gas nozzle until there is a gap of approx. 2-3mm between the tip of
the electrode and the workpiece (arc ignites, current increases to the main current set).
c) Lift off the torch and swivel to the normal position.
Ending the welding process: Remove the torch from the workpiece until the arc goes out.
5.8
Voltage reducing device
The signal light (VRD open circuit voltage reduction) indicates when the voltage reduction device has
been activated. This then ensures that the open circuit voltage between the electrode holder and the
workpiece is reduced to the permissible values.
The voltage reducing device is a requirement in some countries and in many internal company safety
guidelines for power sources.