Quality Of The Weld; Tig Welding - Telwin HF Serie Manuel D'instructions Et D'entretien

CAUTION:
A bad start can be due to the dirty
workpiece, a bad connection between
earth cable and work piece, or the bad
fastening of the electrode in the electro-
de holder.

7.0 QUALITY OF THE WELD

The quality of the weld will depend mainly on
the ability of the welder, on the type of weld
and on the quality of the electrode: Choose
the proper electrode before attempting to
weld, paying attention to the thickness and
composition of the metal to be welded.
Correct welding current.
If the current is too high the elctrode will burn
fast and the weld pool will be wide irregula-
rand difficult to be controlled. If the current is
too low you will lack power and the weld pool
will be narrow and irregular.
Correct arc length.
If the arc is too long it will cause spatters and
small fusion of the welding piece. If the arc is
too short the arc heat will be insufficient cau-
sing the electrode to stick to the workpiece.
Correct welding speed.
The correct welding speed will consent to
achieve a weld of proper width, without wa-
ves or craters.

8.0 TIG WELDING

The TIG process uses the electrical arc
struck between the tungsten electrode of the
torch and the work piece surface.
In TIG welding the torch is always con-
nected to the negative pole of the welder.
Welder preparation:
- Connect the earth cable to the positive
pole of the welder and the earth clamp to the
work piece.
- Connect the TIG torch to the negative
pole of the welder and the gas hose to the
pressure regulator of the gas cylinder.
The flow of the gas is automatically con-
trolled. Use inert gas (argon ) only.
- Turn the inverter on.
10
8.1 WELDING MODE SELECTION
- Select the welding mode, 4T Lift, 2T Lift,
4T HF or 2T HF using the Welding Mode
Selector Switches (3 - 4) on the front panel.
In TIG Welding Mode only two parameters
can be adjusted: welding current and Down-
Slope.
Welding Current:
• Turn the Welding Current Regulation
Knob (5) to set Welding Current.
Down-Slope:
• Set the Down-Slope value acting on
the Down-Slope adjustment knob (6).