Lincoln Electric INVERTEC V270 Bedienungsanleitung Seite 8

the welding current.
R. Downslope Control (V270-T only): In the TIG
welding modes, this control knob will adjust the
downslope time from 0.5 to 20 seconds. (The
upslope time is always 0.5 seconds.) Refer to the
trigger sequence section below to understand how
downslope is activated. In Stick welding mode, this
is not used.
S. Start/Crater Current Control (V270-T only): This
control knob will adjust the Start/Crater current from
10% to 90% of the welding current. For an
explanation of the start/crater operation, refer to the
trigger sequences explained below.
T. Postflow Control (V270-T only): In the TIG welding
modes, this control knob will adjust the shielding
gas postflow time from 0.5 to 30 seconds. (The
preflow time is always 0.5 seconds.) In Stick
welding mode, this is not used.
TIG Trigger Sequences
The V270-S, in Lift TIG mode with a remote control, will
operate in the 2-step mode. For the V270-T, TIG
welding can be done in either the 2-step or 4-step mode
which is selected by the Trigger Mode switch. The
specific sequences of operation for these two trigger
modes are explained below.
In these sequences, the Start/Crater current will be
used. For a V270-S, this current is 20% of the welding
current; for example, if the welding current is 100A the
Start/Crater current will be 20A. For the V270-T, the
Start/Crater current can be adjusted with the Start/Crater
current control knob.
2-Step TIG Sequence
With the Trigger Mode switch in the 2-step position, and
a TIG welding mode selected, the following welding
sequence will occur. To setup the machine for TIG
welding refer to the Output Connections section.
(1)
TORCH
BUTTON
OUTPUT
CURRENT
PRE-FLOW
GAS
1. Press and hold the TIG torch trigger to start the
sequence. The machine will open the gas valve to
start the flow of the shielding gas. After a 0.5
second preflow time, to purge air from the torch
hose, the output of the machine is turned ON. At
this time the arc is started according to the selected
welding mode (Lift TIG or HF TIG). For more
information on the Lift or HF TIG starting methods,
refer to the Mode switch section above.
After the arc is started the output current will be
increased to the welding current. This increase, or
upslope, of the output current takes 0.5 seconds to
(2)
POST-FLOW
--- GAS ON ---
complete.
2. Release the TIG torch trigger to stop welding. The
machine will now decrease the output current at a
controlled rate, or downslope time, until the
Start/Crater current is reached and the output of the
machine is turned OFF. The downslope time is
adjusted by the Downslope Control knob.
After the arc is turned OFF, the gas valve will
remain open to continue the flow of the shielding
gas to the hot electrode and work piece. The
duration of this postflow shielding gas is adjusted by
the Postflow Control knob.
Possible variations of this standard sequence are shown
below. (If necessary, other variations are also available;
contact your Lincoln Electric sales representative for
more information.)
(1)
TORCH
BUTTON
OUTPUT
CURRENT
PRE-FLOW
GAS
As shown above, it is possible to press and hold the TIG
torch trigger a second time during downslope to end the
downslope time and maintain the output current at the
Start/Crater current. When the TIG torch trigger is
released the output will turn OFF and the postflow time
will start.
4-Step Sequence
With the Trigger Mode switch in the 4-step position, and
a TIG welding mode selected, the following welding
sequence will occur. To setup the machine for TIG
welding refer to the Output Connections section.
(1) (2)
TORCH
BUTTON
OUTPUT
CURRENT
PRE-FLOW
GAS
1. Press and hold the TIG torch trigger to start the
sequence. The machine will open the gas valve to
start the flow of the shielding gas. After a 0.5
second preflow time, to purge air from the torch
hose, the output of the machine is turned ON. At
this time the arc is started according to the selected
welding mode (Lift TIG or HF TIG). For more
information on the Lift or HF TIG starting methods,
refer to the Mode switch section above.
After the arc is started the output current will be at
the Start/Crater current. This condition can be
maintained as long or as short as necessary.
8
(2)
POST-FLOW
--- GAS ON ---
(3) (4) (3A)
--- GAS ON ---
POST-FLOW