Tig Welding - Platec INVERTER 250W Manual De Instrucciones

Insert the chosen electrode into the electrode holder. To
strike the electric arc, rub the electrode against the
material to be welded connected to the earth (ground)
clamp. Once the arc is struck, lift the electrode holder
slowly to the normal welding distance.
To strike the arc better, an initial current is supplied which
is higher (hot-start) compared to the welding current. The
electrode on melting deposits in the form of drops onto the
piece to be welded and its outer coating is consumed
supplying the shielding gas for the welding.
To facilitate the fluidity of the welding arc, while the drops
are coming off, which can cause a short circuit between
the electrode and the weld pool, a momentary increase in
the welding current (arc-force) is given, thus preventing the
arc from going out.
If the electrode stays stuck to the piece to be welded, there
is an anti-stick function that, after a certain short-circuit
time, cuts off the power to the generator. Thus you can
detach the electrode without damaging it.
When the coating electrodes are used, you need to
remove the dross from the welding after every pass.
General information for choosing the electrode are given in
the table below; we remind the operator that all data are
for the purpose of information only.
THICKNESS
OF MATERIAL ELECTRODE
(mm)
(mm)
1,5 ÷ 3
3 ÷ 5
5 ÷ 12 3,25
>12

TIG WELDING

I
NSTALLATION
Connect the TIG torch to the negative socket, P1.
Connect the earth clamp to the positive socket, P2.
Connect the gas pipe for the torch to the gas connector A2.
Connect the torch connector to connector J2.
Connect the gas pipe from the gas bottle to the gas
connector A1.
If a TIG torch is used with cooling liquid connect the torch
feed pipe to the quick coupling
pipe to the quick coupling
Connect the unit's power supply cable to connector Z1 and
turn on the cooling unit from the relevant switch.
Connect the unit's power supply cable to connector Z1 and
turn on the cooling unit from the relevant switch.
T
In TIG (Tungsten Inert Gas) welding the electric arc is
struck between a non-consumable electrode (pure
tungsten or an alloy) and the workpiece in an atmosphere
protected by an inert gas (argon).
The TIG lift-arc process is struck by contact. A low short-
circuit welding current is set to limit the tungsten inclusion
on the workpiece. This process does not guarantee a weld
of high quality at the start of the bead.
I N V E R T E R 2 5
I N V E R T E R 2 5
∅
WELDING
CURRENT (A)
2 40 ÷ 75
2,5 60 ÷ 110
95 ÷ 140
4 140 ÷ 190
and the torch return
of the cooling unit.
W
IG ELDING
0 W
0 W
To completely prevent the tungsten being included, you
must not let the electrode touch the piece to be welded.
However you use a start-up with high frequency (HF)
discharge, that allows striking of the electric arc at a
distance.
In many cases, it is useful to have two pre-set welding
currents and to be able to easily change between one
current and the other (Bi-level).
To improve the quality of the final part of the welding bead,
you can control the descent ramp of the welding current
and the post-gas time.
TIG welding is used for welding that must have an
optimum finished appearance with limited post-welding
work.
This requires correct preparation and cleaning of the
edges to be welded.
The rods of consumable material must have mechanical
properties comparable to those of the material to be
welded.
The protection gas used may be pure argon, helium or a
mixture of argon and helium or argon and hydrogen,
whose quantities will vary according to the use.
According to the type of welding that you need to obtain
and the type of material to be welded, you can choose the
welding polarity:
The most commonly used polarity which permits welding
most materials is direct polarity, which means that the TIG
torch is connected to the negative socket P1 and the earth
clamp to the positive socket P2.
This polarity leads to limited wear of the electrode, since
most of the heat is concentrated on the piece to be welded.
This polarity is used for welding materials with high
thermal conductivity, such as copper, but also for welding
steel for which red-coloured thoriated tungsten (2%
thorium) electrodes are recommended. The diameter of
the electrode varies according to the welding current
chosen.
D
IRECT
Pulsed current allows a better control of the weld bath and
ensures a restricted thermally changed zone, with fewer
deformations and less danger of gas inclusion and hot
cracking.
When the frequency increases, a more stable and
concentrated welding arc is obtained. This allows you to
get a higher quality weld on thinner materials.
With the SYNERGIC PULSATED TIG function the main
parameters of pulsated welding are managed by the
microprocessor in an optimal manner.
Inverse polarity, on the other hand, allows you to weld
alloys covered with a refractory oxide coating (whose
melting point is higher than the metal), e.g. aluminium (and
its alloys) and magnesium.
As opposed to direct polarity, here you attach the TIG
torch to the positive socket, P2, and the earth clamp to the
negative socket, P1.
This polarity puts the electrode under a great amount of
heat, with the resultant wear on it. For this reason, you can
only carry out welding at low currents.
1 9
1 9
D P
IRECT OLARITY
P W P C
OLARITY ITH ULSED
I P
NVERSE OLARITY
E n g l i s h
E n g l i s h
URRENT