Lincoln Electric IMVERTEC V160-T - Manual (Page 18)

b-5 OPERATION b-5
V160-T
4-Step Sequence
Note: 4-Step works with Arc Start Switch only. Amptrol™
type devices will not work properly and should not
be used. The Arc Start Switch's actuator is also
referred to as the "Tig torch trigger" in the following
sequence.
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 0.5 second
preflow time to purge air from the torch hose, the out-
put of the machine is turned ON. At this time the arc
can be started. After the arc is started the output cur-
rent will be at the Start/Finish current. This condition
can be maintained as long or as short as necessary.
If the Start/Finish current is not necessary, do not hold
the TIG torch trigger as described at the beginning of
this step. Instead, quickly press and release the trig-
ger. 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 increase to the welding current.
The time for this increase or upslope is presettable.
The default is 0.5 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
controlled rate or downslope time, until the Start/Finish
current is reached. The downslope time is adjusted by
the Downslope Parameter. This Start/Finish current
can be maintained as long or as short as necessary.
4. Release the TIG torch trigger.
The output current of the machine will turn OFF and
the gas valve will remain open to continue the flow of
the shielding gas. The duration of this postflow time is
adjusted by the Postflow control knob. This operation
is shown in (4 step diagram 1).
4 Step Diagram 1
Possible variations of this standard sequence are
shown below. It is possible to press and hold the TIG
torch trigger another time to end the downslope time
and maintain the output current at the Start/Finish cur-
rent. When the TIG torch trigger is released the output
will turn OFF and postflow will begin. This operation
shown in (4 step diagram 2).
4 Step Diagram 2