Power Fist SMART TIG AC/DC-200P Manuel De L'utilisateur page 18

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STRIKING ARC METHOD
1. Lift Arc: Use this method when welding brittle
or hard steel.
a. Hold the electrode (Fig. 12-1) upright above
the workpiece, no closer than 4 mm.
b. Tap down onto the workpeice (Fig. 12-2)
and quickly lift up about 2 to 4 mm to ignite
the arc (Fig. 12-3). The tapping motion
shouldn't last more than 2 seconds.
2. HF Ignition: Allows the arc to start without
touching the workpiece
a. Hold the tungsten electrode within 2 to 4 mm.
b. An arc will establish itself.
IMPORTANT! When operating the welding unit in HF ignition mode, the ignition spark can cause interferences in
equipment near the welding unit. Be sure to take specially safety precautions or shielding measures.
3. Scratch Arc: Hold the electrode to scrape the workpiece
for striking an arc. This method is used primarily for
stick welding.
a. Place the welding torch at an angle (Fig. 13).
b. Scrape the electrode along the workpiece.
c. Lift the welding torch 2 to 4 mm to create an arc.
TIG WELDING (4T OPERATION)
TIG welding set to 4T is suitable for the welding of medium
thick plates. The welding unit can preset the start current
(upslope time) and crater current (downslope time). This allows the welding unit to switch from one setting to the next
by pressing or releasing the torch switch as instructed below.
1. Press and hold the torch switch. The electromagnetic gas valve is turned on. The shielding gas starts to flow.
2. Pre-gas time lasts between 0.1 to 1 second.
3. The arc is ignited at the starting current value.
4. Release the torch switch and the output current rises to the full value. The upslope time can be adjusted.
5. The welding unit begins the welding task. The output current remains constant, unless pulse is selected.
a. Pulse output alternates between the base and welding current during the welding process.
6. Pressing the torch switch again drops the current output to the downslope setting to the crater current output to
finish the weld. The downslope time can be adjusted.
7. Release the torch switch to stop the arc. The gas will continue to flow to protect the weld for 0.1 to 10 seconds. The
post-gas can be set with the adjustment knob on the front panel
8. The electromagnetic valve closes and stops the gas from flowing.
9. The welding task is complete.
TIG WELDING (2T OPERATION)
TIG welding to 2T does not use either preset start current (upslope) or crater current (downslope) function. The 2T
setting is suitable for the re-tack welding, transient welding or thin plate welding.
1. Press and hold the torch switch. The electromagnetic gas valve is turned on and the shielding gas starts to flow.
2. Pre-gas time lasts between 0.1 to 1 second.
3. The arc ignites and the output current rises to the set welding current (Iw or Ib) from the minimum welding current.
4. The welding unit begins the welding task. The output current remains constant, unless pulse is selected.
a. Pulse output alternates between the base and welding current during the welding process.
5. Release the torch switch and the welding current drops to the minimum welding current from the setting current (Iw
or lb) and then arc is turned off.
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SMART TIG AC/DC-200P Inverter Welding Machine
For technical questions call 1-800-665-8685
V4.1
Fig. 12
Fig. 13