Step / 4 Step Operation - Lincoln Electric POWER FEED 10M SINGLE/DUAL SVM172-A Service Manual

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Recalling from Memory
To recall the contents of a memory into the active proce-
dure, momentarily push the desired memory button (for
less than 2 seconds). The saved parameters will be
copied into the active procedure, and the LED of the
memory button will light indicating the source of the infor-
mation. As with saving to memory, this light will remain lit
as long as the contents of the source memory remain
equal to the contents of the associated procedure.
If a constant current mode is saved to memory with the
power source in the "on" state, the "on" status will be
changed to "off" when the procedure is recalled. This pre-
vents a potential safety hazard if a memory button is
pushed and the power source unexpectedly turns on.

2 STEP / 4 STEP OPERATION

The Wire Drive has a 2 Step / 4 Step switch located
near the gun connector. 2-Step Trigger Mode operation
requires the operator hold the gun trigger closed in
order to weld. 4-Step Trigger Mode eliminates the need
to hold the gun trigger closed while welding. User-
selectable 4-step modes with or without current inter-
lock. The switch in the down position will enable 2-Step
operation and in the up position enables 4 -Step oper-
ation. This switch has no effect in CC modes of opera-
tion, such as stick welding. Both 2 and 4 -Step can be
operated in Synergic and Non-Synergic modes. In a
Synergic mode, machine output tracks Wire Feed
Speed (WFS) during welding. In Non-Synergic modes,
machine output is independent of WFS.
2 Step Synergic Operation:
Without Start/Crater/Burnback functions active
Waveform Sequence:
1. Trigger is pulled; Preflow sequence begins and runs
until preflow timer expires.
2. Strike sequence initiates until Arc is established.
3. Arc established; Weld sequence begins.
4. Trigger released (Arc extinguished); Postflow
sequence begins and runs until postflow timer
expires.
5. End of sequence.
1 2 3
WFS vs. Work point Waveform
= solid line represents WFS
---= dashed line represents Work point or Machine Output
OPERATION
2 Step Synergic Operation:
With Burnback function active.
Waveform Sequence:
1. Trigger is pulled; Preflow sequence begins and
2. Run-In sequence initiates until Arc is established.
3. Arc established; Weld sequence begins.
4. Trigger released (Arc extinguished); Burnback
5. Postflow sequence begins and runs until postflow
6. End of sequence.
1
---= dashed line represents Work point or Machine Output
2 Step Synergic Operation:
With Start/Crater/Burnback functions active.
Waveform Sequence:
1. Trigger is pulled; Preflow sequence begins and
2. Run-In sequence initiates until Arc is established.
3. Arc established; Start sequence begins and runs
4. Weld sequence begins.
5. Trigger released; Crater sequence begins and
6. Arc Extinguished; Burnback sequence begins and
7. Postflow sequence begins and runs until postflow
8. End of process.
1
4 5
---= dashed line represents Work point or Machine Output
POWER FEED 10M SINGLE/DUAL
runs until preflow timer expires.
sequence begins and runs until burnback timer
expires.
timer expires.
2 3
WFS vs. Work point (Output) Waveform
= solid line represents WFS
runs until preflow timer expires.
for the amount of time set.
runs until crater timer expires.
runs until burnback timer expires.
timer expires.
2 3 4
WFS vs. Work point (Output) Waveform
= solid line represents WFS
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4 5 6
5 6 7 8