Impax IM-TIG200 Instruction Manual page 34

TIG OPERATION
Release the TIG torch switch to end sequence.
The machine will now decrease output to finish
current in time set by down slope, Fig.25.
Fig 25
The down slope control dial controls the time
the current will take to reduce at the end of the
weld. This helps eliminate craters or pin holes
forming. Adjustment 0-5 seconds.
Once at the finished current the machine will
stop output and the gas valve will continue to
operate for a selected time (post flow), Fig.26.
Fig 26
The post flow dial controls the time between arc
ending and post-flow. Adjustment 1-10 seconds.
Possible variations of this standard sequence
are shown in diagram below. It is possible to
press and hold TIG torch switch a second time
during down slope time to restart. After the
switch is pressed the output current will raise to
base (main) current (Fig.27).
Fig 27
When the trigger mode is in the 4 step position
the following sequence will occur (Fig.28).
Fig 28
Press and hold the TIG torch switch to start
sequence.
The machine will open the gas valve to start a
flow of shield gas, after a 150ms pre-flow time to
purge air from torch hose the welding output of
machine will be turned on and the arc will be
started. Keep the torch 2~4mm away from the
work piece to ignite the arc. When the arc is
established the HF stops, and current rises to
the preset value; Release the torch trigger, and
welding continues at the preset current level.
Press the torch trigger again and release it,
current begins to decrease to the minimum
value, and then arc stops; Gas keeps flowing for
the post-flow time, and welding ends.
Remember to turn off the gas immediately when
you finish welding.
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