Lincoln Electric INVERTEC V205-T DC Operator's Manual page 17

V205-T DC & V205-T AC/DC
6. Digital Display - displays currently set values for each mode
or welding parameter.
7. Local/Remote push button - Selects the welding current
adjusting system:
• from front panel
• from remote control
The LED beside the symbol confirms the selection.
8. Tig Trigger Sequences - For the V205-T AC/DC, TIG welding
can be done in either the 2-step or 4-step mode which is
selected with the Trigger Mode Push Button.
2-Step Sequence
With the Trigger Mode switch in the 2-step position, the follow-
ing welding sequence will occur. This sequence is shown in (2-
step diagram 1)
1. Press and hold the Arc Start Switch 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.
After the arc is started the output current will be increased from
the start current to the welding current. Both the start current
and increase, or upslope time are presettable. The default start
current is 15 amps and the default upslope time is 0.2 seconds.
2. Release the Arc Start Switch to stop welding.
The machine will now decrease the output current at a con-
trolled rate, or downslope time, until the Finish current, (also
commonly referred to as Crater Current) is reached and the out-
put of the machine is turned OFF. Both the Downslope Time and
the Finish Current are can be preset.
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 adjust-
ed by the Postflow Parameter.
Possible variations of this standard sequence is shown in (2 step
diagram 2). It is possible to press and hold the TIG torch trigger a
second time during downslope to restart. After the trigger is
pressed the output current will increase to the welding current.
This operation is shown in (2 step diagram 2).
4-Step Sequence
With the 4-step Selected, the following welding sequence will
occur.
2 STEP DIAGRAM 1
(1)
2 STEP DIAGRAM 2
(1)
1. Press and hold the Arc Start Switch 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.
After the arc is started the output current will be at the Start cur-
rent. This condition can be maintained as long or as short as
necessary.
If the Start current is not necessary, do not hold the TIG torch
trigger as described at the beginning of this step. Instead, quick-
ly press and release the trigger. In this condition, the machine
will automatically pass from Step 1 to Step 2 when the arc is
started.
2. Release the TIG torch trigger to start the main part of the weld.
The output current will be increased from the start current to the
welding current. Both the start current and increase, or upslope
time are presettable. The default start current is 15 amps and
the default upslope time is 0.2 seconds.
3. Press and hold the TIG torch trigger when the main part of the
weld is complete.
The machine will now decrease the output current at a con-
trolled rate, or downslope time, until the Finish current is
reached. Both the Downslope Time and the Finish Current are
presettable. This Finish current can be maintained as long or as
short as necessary.
B 3
OPERATION
(2)
(2) (2)