Output Limitations; Dc Tig Welding; Welding Polarity; Dc Electrode Negative Polarity - Lincoln Electric INVERTEC V205-T DC Operator's Manual

V205-T DC & V205-T AC/DC

OUTPUT LIMITATIONS

The maximum output current as specified in the installation sec-
tion of this manual is derated in several situations; alternate AC
Wave Forms, elevated AC Frequencies and 115V input.
• Alternate AC Wave Forms (See Set Up Menu)¹
Square 200 amps max. output
Sinusoidal 150 amps max. output
Triangular 120 amps max output
• Elevated AC Frequencies¹
Above 85Hz (AC output) the square wave output is limit-
ed to 170 amps. Elevated AC Frequencies do not effect
the output of Sinusoidal and Triangular Waveforms.
• 115V Operation
150 A TIG Mode
110 A Stick Soft mode
100 A Stick Crisp Mode
These derated values have been programmed into the Invertec
V205-T to ensure reliable operation.
¹ AC/DC model only

DC TIG WELDING

(see FIGURE B.3)
The TIG (Tungsten lnert Gas) welding process is based on the
presence of an electric arc between a non-consumable electrode
(pure or alloyed tungsten with an approximate melting tempera-
ture of 3370°C) and the workpiece. An inert gas (typically argon)
atmosphere protects the weld pool.
To avoid inclusions of tungsten in the joint, the electrode should
not contact the workpiece. For this reason the arc is started
through a Hi. Freq. generator.
For situations requiring no Hi. Freq., Touch Start Tig reduces the
short-circuit current to keep tungsten inclusions to the minimum.
To improve weld bead quality at the end of the weld it is important
to carefully control the downslope of current and ensure proper
gas coverage over the weld.
1) Workpiece
2) F iller material
3) Non-consumable electrode 7 ) lnert gas (typically argon)
4) Torch

WELDING POLARITY

DC Electrode Negative Polarity (Direct Current Straight
Polarity)
(see Figure B.4)
While Welding, there is a continuous flow of electrons from the
electrode to the workpiece.
This is the most used polarity, ensuring limited wear of the elec-
trode, since the majority of the heat concentrates on the anode
(workpiece). Narrow and deep welds are obtained with high travel
speeds.
Most materials, with the exception of aluminum and magnesium,
are welded with this polarity.
B 6
OPERATION
FIGURE B.3
5) Flowmeter
6) Pressure reducer
8) Power source
FIGURE B.4