Draw arc ("Lift Arc")
Touch the workpiece briefly with the electrode
■
at the point to be welded and lift the arc
slightly: The arc burns between workpiece and
electrode.
Hot start
During "Electrode" welding, a higher current can be
set for drawing the arc, irrespective of the welding
current (see Setting of ancillary parameters).
Arc force
In order to improve the welding behaviour, the
system has an arc force function: With short arcs
or during brief short-circuits, the welding current is
higher than the set value.
Anti-stick
If a short-circuit of the electrode with the workpiece
lasts longer than the normal ignition (e.g. if the
electrode "sticks"), the welding current is reduced to
less than 20 A.
This prevents overheating of the electrode and the
short-circuit can be remedied without drawing an
arc.
If the system does not detect the short-circuit, the
anti-stick device is not tripped. This can be the case
with
— Very thin electrodes where the welding cur-
rent is set too high,
— Long and excessively thin welding cables,
— Poor ground contact.
TIG welding (Fig. IV)
Inserting the electrode
Grind the end of the tungsten electrode [22] so
■
that is pointed
Unscrew the clamping cap [23]
■
Push the tungsten electrode [22] through the
■
appropriate clamping sleeve [24] and secure
Screw on the clamping cap [23] again.
■
Do not remove the clamping sleeve hous-
ing [25] or gas nozzle [26].
Functions of welding torch buttons
Torch button 1 [27]: Start/Stop
Starting and stopping the welding process
Torch button 2 [28]: Secondary current
During the welding process, a secondary current can
be called up by pressing the welding torch button
(standard setting: 50% of main current). The second-
ary current flows for as long as the welding torch
button [2] is pressed.
If the Slope function has been activated, this weld-
ing torch button allows the current reduction to be
terminated prematurely.
Connecting the TIG welding torch (Fig. V)
Connect the TIG torch to the negative (–)
■
socket [3] and secure it by turning the connector
in clockwise direction.
Insert the welding torch control plug into the
■
socket [19].
Important
Only the control plug of the TIG
welding torch may be inserted into the
socket [19] of the machine.
Never plug in any other form of controller, such as
the relay contact of an automation control system or
a push-button unit as the socket has the full trigger
voltage at all times, even when the control plug is
not inserted. Danger for connected electrical parts
or the operator!
Connecting the workpiece line
Connect the workpiece lead to the positive (+)
■
socket [4].
Secure the connecting plug by turning in clock-
■
wise direction.
Fasten the ground clamp with good electrically
■
conductive contact to a bare metal part of the
welding bench or workpiece.
21