Tig Trigger Sequences; 2-Step Trigger Sequence; 2-Step Repeat Trigger Sequence - Lincoln Electric OPTIMARC AC/DC 350-TP Operator's Manual

B-9
Water-cooling protection
Output IGBT Top tube protection
Output IGBT Down tube protection
Relay fault
Over current protection

TIG Trigger Sequences

TIG welding can be operated in 2-Step, 2-Step Repeat, 4-
Step and 4-Step Repeat modes. The specific sequences
of operations for the trigger modes are explained below.
Symbols used:
Torch Button
Output Current
Gas Pre-flow
Gas
Gas Post-flow

2-Step Trigger Sequence

With the 2-step trigger mode and a TIG welding mode
selected, the following welding sequence will occur.
1. Press and hold the TIG torch trigger. The machine
will open the gas valve to start the flow of the
shielding gas. After the Pre-flow 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. After the arc is started,
the output current will be increased and reached set
current at the end of upslope time.
OPERATION
2. Release the TIG torch trigger. The machine will
decrease the output current in downslope time, the
output is turned OFF until reached the crater current.
The gas valve will remain open to continue the flow
of the shielding gas until post flow time is over.

2-Step Repeat Trigger Sequence

With the 2-Step Repeat trigger mode and a TIG welding
mode selected, the following welding sequence will occur.
This sequence is the same as 2-Step, except when the
switch is pressed while in final slope the welding current
will ramp again and resume. This process can be
repeated as many times as necessary. When finished
welding, simply release the trigger and allow the finishing
current to end and the output to switch OFF followed by
the post flow time.
4-Step Trigger Sequence
With the 4-step trigger mode and a TIG welding mode
selected, the following welding sequence will occur.
1. Press and hold the TIG torch trigger. The machine
will open the gas valve to start the flow of the
shielding gas. When the pre-flow time is over,
machine is in OCV mode, and then begin arc starting
and keep the output current at the value of arc-
starting current.
2. Release the TIG torch trigger to start the upslope
function. The output current will be increased at
upslope time, until the Welding current is reached.
3. Press and hold the TIG torch trigger. The machine
will now decrease the output current at downslope
time, until the Crater current is reached.
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OPTIMARC AC/DC 350-TP
B-9
Rev. 05