Description of function
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3.3.18.2 Pre-flow gas time ( A )
The pre-flow gas time is the time for which the gas solenoid opens after
depressing the torch button 1 until the arc ignition cycle starts. This ensures that
the tip of the tungsten electrode and the workpiece is protected from the
atmosphere before the ignition takes place
If during the gas post flow time the welding process is re-started, the processor
automatically set the gas pre-
flow time to „zero“. This reduces the waiting time
and improves efficiency of the machine. This is very important when tack welding
for example.
3.3.18.3 Ignition Energy ( B )
The ignition energy is infinitely variable between 10% and 99% for both the Lift
Arc and HF ignition arc starting modes.
In direct relationship to the welding current setting I1, the processor then
automatically applies the pre-selected value depending upon the setting of the
welding current I1 during the ignition cycle. The pre-selected value of the ignition
energy will be dependant upon the type of tungsten electrode, and the diameter,
as well as the welding application.
When welding on thin materials and when using small diameter tungsten
electrodes the value for the ignition energy will be lower.
3.3.18.4 Start current ( C )
The start current is the current at which the machine produces directly after the
arc is struck. The value is infinitely variable between 10% and 99% of the welding
current I1. E.g. if the start current is set at 40% (C40) and the welding current is
set at 100A then the start current will be 40A. The advantages of adjusting the
start current are:
Lower loading on the electrode due to lower thermal shock.
Search arc can be set in the latched (4 step) trigger mode, to start at the
beginning of a weld.
The welding with a reduced current is possible at the beginning of a weld, or
where heat build up occurs.
3.3.18.5 Current upslope time ( D )
The current upslope time is the time in which the welding current rises in a linear
transition from the start current to the welding current (I1). In the non-latched
torch trigger mode (2step), the time commences directly after the arc has ignited.
In the latched torch trigger mode (4step), the time starts as soon as the trigger is
released after step 1 and current is flowing.
3.3.18.6 Crater fill current ( E )
The crater fill current is the current at which the welding process will be
terminated. The setting is infinitely variable between 10% and 99% of the welding
current I1. E.g. if the crater fill current is set at 40% (E40) and the welding current
is set at 100A then the crater fill current will be 40A. The advantages of adjusting
the crater fill current are:
The elimination of crater cracking and cracking at the end of the weld seam
due to rapid cooling of the weld pool.
Manual pulsing (see chapter 3.2.6).
The welding with a reduced current is possible at the end of the weld on
edges, or where heat build up occurs.
