Mma Welding - Telwin Tecnica 171/S Manual De Instrucciones

POWER SUPPLY OUTLET.
THE ELECTRICAL CONNECTIONS MUST BE MADE ONLY AND
EXCLUSIVELY BY AUTHORISED OR QUALIFIED PERSONNEL.
PREPARATION
Unpack the welding machine, assemble the separate parts contained in
the package.
Assembling the return cable-clamp
Assembling the welding cable-electrode holder clamp
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. L).
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.
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:
- Type A ( ) for single phase machines;
- 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 = 0.24 ohm.
- 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).
- Unless otherwise specified (MPGE), the welding machines are
compatible with power generating sets for voltage oscillations up to ±
15%.
For correct use, the power generating set must be brought to steady
conditions before being able to connect the inverter.
- PLUG AND OUTLET:
- The 230V model is fitted at the factory with a power supply cable
and normalised plug, (2P + T) 16A/250V .
It can therefore be connected to 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.
- For welding machines without a plug (115/230V models), connect
a normalised plug (2P + T) - 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.
Fig. E
Fig. F
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).
CONNECTION OF THE WELDING CABLES
WARNING!
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
2
machine.

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.
WELDING OPERATIONS WITH DIRECT CURRENT
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
- It is most important that the user refers to the maker's instructions
indicated on the stick electrode packaging. This will indicate the correct
polarity of the stick electrode and the most suitable current.
- The welding current must be regulated according to the diameter of
the electrode in use and the type of the joint to be carried out: see
below the currents corresponding to various electrode diameters:
Ø Electrode (mm)
1.6
2
2.5
3.2
4
- The user must consider that, according to the electrode diameter,
higher current values must be used for flat welding, whereas for vertical
or overhead welds lower current values are necessary.
- As well as being determined by the chosen current intensity, the
mechanical characteristics of the welded join are also determined by
the other welding parameters i.e. arc length, working rate and position,
electrode diameter and quality (to store the electrodes correctly, keep
them in a dry place protected by their packaging or containers).
Procedure
- Holding the mask IN FRONT OF THE FACE, strike the electrode tip on the
workpiece as if you were striking a match. This is the correct strike-up
method.
WARNING: do not hit the electrode on the workpiece, this could
damage the electrode and make strike-up difficult.
- As soon as arc is ignited, try to maintain a distance from the workpiece
equal to the diameter of the electrode in use. Keep this distance as
much constant as possible for the duration of the weld. Remember
that the angle of the electrode as it advances should be of 20-30 grades
- 7 -
BEFORE MAKING THE
Welding current (A)
min.
25
40
60
80
120
FOLLOWING
max.
50
80
110
160
200