Telwin TIG 182 Bedienungsanleitung Seite 7

Led 4
First function:
END SLOPE
In TIG AC/DC mode, it allows adjustment of the welding current's END SLOPE
upon the release of the torch pushbutton; this adjustment allows to avoid formation
of the crater at the end of the welding and permits the filling with welding material
during the current down slope.
Second function:
FREQUENCY
In TIG AC/DC PULSED mode ( I
pulsing frequency.
In TIG AC mode with pulsing disabled( I
frequency in AC.
Led 5
First function:
POST GAS
In TIG AC/DC mode, it allows adjustment of the post gas timing in seconds.
Second function:
BALANCE
In the pulsed-TIG AC/DC mode, it allows adjustment of the BALANCE. This
parameter represents the relationship (in percentage) between the time during
which the current is at the greater level I
DC models in the TIG AC mode (pulse disabled), the parameter represents a ratio
between time with positive current and time with negative current: if the parameter
value is positive, heating and piece penetration increase, if it is negative, the
surface is cleaner and the electrode heats more, while if the parameter value
is zero, the positive and negative currents during the AC frequency period are
balanced. (TAB. 5).
7- Fast-latch negative plug (-) to connect the welding cable.
8- Connector for the torch pushbutton cable connection.
9- Fitting for the TIG torch gas pipe connection.
10- Fast-latch positive plug (+) to connect the welding cable.
5. INSTALLATION
WARNING! CARRY OUT ALL INSTALLATION OPERATIONS AND
ELECTRICAL CONNECTIONS WITH THE WELDING MACHINE COMPLETELY
SWITCHED OFF AND DISCONNECTED FROM THE POWER SUPPLY OUTLET.
THE ELECTRICAL CONNECTIONS MUST BE MADE ONLY AND EXCLUSIVELY
BY AUTHORISED OR QUALIFIED PERSONNEL.
5.1 PREPARATION
Unpack the welding machine, assemble the separate parts contained in the package.
5.1.1 Assembling the return cable-clamp (FIG. E)
5.1.2 Assembling the welding cable-electrode holder clamp (FIG. F) (MMA)
5.1.3 How to lift the welding machine
All the welding machines described in this handbook should be lifted using the handle
or strap supplied if provided for the particular model (fitted as described in FIG. F1).
5.2 POSITION OF THE WELDING MACHINE
Choose the place to install the welding machine so that the cooling air inlets and
outlets are not obstructed (forced circulation by fan, if present); at the same time make
sure that conductive dusts, corrosive vapours, humidity etc. will not be sucked into
the machine.
Leave at least 250mm free space around the welding machine.
WARNING! Position the welding machine on a flat surface with
sufficient carrying capacity for its weight, to prevent it from tipping or moving
hazardously.
5.3 CONNECTION TO THE MAIN POWER SUPPLY
- Before making any electrical connection, make sure the rating data of the welding
machine correspond to the mains voltage and frequency available at the place of
installation.
- The welding machine should only be connected to a power supply system with the
neutral conductor connected to earth.
- To ensure protection against indirect contact use residual current devices of the
following types:
) for single phase machines;
- Type A (
- Type B ( ) for 3-phase machines.
- To comply with the requirements of the EN 61000-3-11 (Flicker) standard we
recommend connecting the welding machine to interface points of the power supply
that have an impedance of less than Zmax = 0.227ohm (1~).
- the welding machine does not fall within the requisites of IEC/EN 61000-3-12
standard.
Should it be connected to a public mains system, it is the installer's responsibility
to verify that the welding machine itself is suitable for connecting to it (if necessary,
consult the distribution network company).
5.3.1 Plug and outlet
Connect a normalised plug (2P + T (1~)) - having sufficient capacity- to the power
cable and prepare a mains outlet fitted with fuses or an automatic circuit-breaker; the
special earth terminal should be connected to the earth conductor (yellow-green) of
the power supply line. Table (TAB.1) shows the recommended delayed fuse sizes in
amps, chosen according to the max. nominal current supplied by the welding machine,
and the nominal voltage of the main power supply.
WARNING! Failure to observe the above rules will make the (Class 1)
safety system installed by the manufacturer ineffective with consequent serious
risks to persons (e.g. electric shock) and objects (e.g. fire).
is different from "Off"), it allows the setting of the
1
= "OFF" ), it allows adjustment of the
1
and the total pulsing period. With AC/
2
5.4 CONNECTION OF THE WELDING CABLES
WARNING! BEFORE MAKING THE FOLLOWING CONNECTIONS MAKE
SURE THE WELDING MACHINE IS SWITCHED OFF AND DISCONNECTED FROM
THE POWER SUPPLY OUTLET.
Table (TAB. 1) gives the recommended values for the welding cables (in mm
depending on the maximum current supplied by the welding machine.
5.4.1 TIG welding
Torch connection
- Insert the current-carrier cable in the specific fast-latch terminal (-). Link the three-
pole connector (torch pushbutton) to the specific plug. Connect the gas pipe of the
torch to the specific fitting.
Connection of the welding current return cable
- This must be connected to the piece to be welded or to the metal bench on which it
is resting, as close as possible to the welding point in progress.
This cable must be connected to the terminal with symbol (+).
Connection to the gas bottle
- Screw in the gas regulator to the gas bottle's valve, interposing the specific reductor
provided as an accessory.
- Connect the gas inflow pipe to the regulator and tighten the clamp supplied.
- Loosen the adjustment ring nut of the gas regulator before opening the gas bottle's
valve.
- Open the gas bottle and adjust the quantity of (l/min) according to the indicative data
for the specific use; see table (TAB. 4); any adjustments of the gas outflow may
be carried out during the welding operation, always turning the ring nut of the gas
pressure regulator. Check the sealing of piping and connections.
WARNING! Always close the valve of the gas bottle at the end of work
operations.
5.4.2 MMA WELDING
Almost all coated electrodes are connected to the positive pole (+) of the power
source; as an exception to the negative pole (-) for acid coated electrodes.
Connecting the electrode-holder clamp welding cable
On the end take a special terminal that is used to close the uncovered part of the
electrode.
This cable is connected to the terminal with the symbol (+)
Connecting the welding current return cable
This is connected to the piece being welded or to the metal bench supporting it, as
close as possible to the join being made.
This cable is connected to the terminal with the symbol (-)
Warnings:
- Turn the welding cable connectors right down into the quick connections (if present),
to ensure a perfect electrical contact; otherwise the connectors themselves will
overheat, resulting in their rapid deterioration and loss of efficiency.
- The welding cables should be as short as possible.
- Do not use metal structures which are not part of the workpiece to substitute the
return cable of the welding current: this could jeopardise safety and result in poor
welding.
6. WELDING: DESCRIPTION OF THE PROCEDURE
6.1 TIG WELDING
TIG welding is a welding procedure that exploits the heat produced by the electric arc
that is struck, and maintained, between a non-consumable electrode (tungsten) and
the piece to be welded. The tungsten electrode is supported by a torch suitable for
transmitting the welding current to it and protecting the electrode itself and the weld
pool from atmospheric oxidation, by the flow of an inert gas (usually argon: Ar 99.5)
which flows out of the ceramic nozzle (FIG. G).
To achieve a good weld it is absolutely necessary to use the exact electrode diameter
with the exact current, see the table (TAB. 4).
The electrode usually protrudes from the ceramic nozzle by 2-3mm, but this may
reach 8mm for corner welding.
Welding is achieved by fusion of the edges of the joint. For properly prepared thin
pieces (up to about 1mm) weld material is not needed (FIG. H).
For thicker pieces it is necessary to use filler rods of the same composition as the base
material and with an appropriate diameter, preparing the edges correctly (FIG. I). To
achieve a good weld the pieces should be carefully cleaned and free of oxidation, oil,
grease, solvents etc.
6.1.1 HF and LIFT strike
HF strike:
The electric arc is struck without contact between the tungsten electrode and the piece
being welded, by means of a spark generated by a high frequency device. This strike
mode does not entail either tungsten inclusions in the weld pool or electrode wear and
gives an easy start in all welding positions.
Procedure:
Press the torch button, bringing the tip of the electrode close to the piece (2 -3mm),
wait for the arc strike transferred by the HF pulses and, when the arch has struck, form
the weld pool on the piece and proceed along the joint.
If there are difficulties in striking the arc even though the presence of gas is confirmed
and the HF discharges are visible, do not insist for long in subjecting the electrode to
HF action, but check the integrity of the surface and the shape of the tip, dressing it
on the grinding wheel if necessary. At the end of the cycle the current will fall at the
slope down setting.
LIFT strike:
The electric arc is struck by moving the tungsten electrode away from the piece to be
welded. This strike mode causes less electrical-radiation disturbance and reduces
tungsten inclusions and electrode wear to a minimum.
Procedure:
Place the tip of the electrode on the piece, using gentle pressure. Press the torch
button right down and lift the electrode 2-3mm with a few moments' delay, thus striking
the arc. Initially the welding machine supplies a current I
welding current setting will be supplied. At the end of the cycle the current will fall to
zero at the slope down setting.
6.1.2 TIG DC welding
TIG DC welding is suitable for all low- and high-carbon steels and the heavy metals,
copper, nickel, titanium and their alloys.
For TIG DC welding with the electrode to the (-) terminal the electrode with 2% thorium
(red band) is usually used or else the electrode with 2% cerium (grey band).
It is necessary to sharpen the tungsten electrode axially on the grinding wheel,
as shown in FIG. M, making sure that the tip is perfectly concentric to prevent arc
deviation. It is important to carry out the grinding along the length of the electrode.
This operation should be repeated periodically, depending on the amount of use and
wear of the electrode, or when the electrode has been accidentally contaminated,
oxidised or used incorrectly. In TIG DC mode 2-stroke (2T) and 4-stroke(4T) operation
are possible.
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)
2
, after a few moments the
BASE