Telwin TECHNOMIG 200 Manuel D'instructions page 9

preparing the edges correctly (FIG.O). To achieve a good weld the
pieces should be carefully cleaned and free of oxidation, oil, grease,
solvents etc.
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. Lift
the electrode 2-3mm with a few moments' delay, thus striking the arc.
Initially the welding machine supplies a current I
moments the welding current setting will be supplied.
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% cerium (grey band).
It is necessary to sharpen the tungsten electrode axially on the
grinding wheel, as shown in FIG. P, 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.
MMA WELDING WITH COATED ELECTRODES
- 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
(TAB.7).
- 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.
- In addition to being determined by the selected current intensity, the
mechanical characteristics of the welded join are 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 dry and protected by suitable packaging or containers).
- The properties of the weld also depend on the ARC-FORCE value
(dynamic behaviour) of the machine.
- It should be noted that high ARC-FORCE values achieve better
penetration and allow welding in any position typically with basic
and cellulose electrodes, low ARC-FORCE values give a softer,
spray-free arc typically with rutile electrodes.
The welding machine is also equipped with HOT START and ANTI
STICK devices to guarantee easy starting and to prevent the
electrode from sticking to the piece.
Procedure
- Keeping the mask IN FRONT OF THE FACE, rub the tip of the
electrode on the piece to be welded with a movement like striking a
match; this is the best way to strike the arc.
WARNING: DO NOT TAP the electrode on the piece; this risks
damaging the coating and making arc strike difficult.
- As soon as the arc has struck, try to keep at a distance from the
piece equivalent to the diameter of the electrode being used and
keep this distance as constant as possible while carrying out the
weld; bear in mind that electrode inclination in the direction of
progress should be about 20-30 degrees (FIG.Q).
- At the end of the welded seam, take the end of the electrode
backwards slightly with respect to the direction of progress, above
the crater so as to fill it, then lift the electrode quickly from the weld
pool so that the arc is extinguished. (Appearance of the weld
seam FIG. R).
7. MAINTENANCE
______________________________________________________
WARNING! BEFORE CARRYING OUT MAINTENANCE
OPERATIONS MAKE SURE THE WELDING MACHINE IS
SWITCHED OFF AND DISCONNECTED FROM THE MAIN POWER
SUPPLY.
______________________________________________________
ROUTINE MAINTENANCE:
ROUTINE MAINTENANCE OPERATIONS CAN BE CARRIED OUT
BY THE OPERATOR.
Torch
- Do not put the torch or its cable on hot pieces; this would cause the
insulating materials to melt, making the torch unusable after a very
short time;
- Make regular checks on the gas pipe and connector seals;
- Every time the wire reel is changed, blow out the wire-guide hose
using dry compressed air (max. 5 bar) to make sure it is not
damaged;
- Before every use, check the wear and correct assembly of the parts
at the end of the torch: nozzle, contact tip, gas diffuser.
Wire feeder
- Make frequent checks on the state of wear of the wire feeder
rollers, regularly remove the metal dust deposited in the feeder
area (rollers and wire-guide infeed and outfeed).
EXTRAORDINARY MAINTENANCE:
EXTRAORDINARY MAINTENANCE OPERATIONS SHOULD BE
CARRIED OUT ONLY AND EXCLUSIVELY BY SKILLED OR
AUTHORISED ELECTRICAL-MECHANICAL TECHNICIANS.
______________________________________________________
WARNING! BEFORE REMOVING THE WELDING MACHINE
PANELS AND WORKING INSIDE THE MACHINE MAKE SURE THE
WELDING MACHINE IS SWITCHED OFF AND DISCONNECTED
FROM THE MAIN POWER SUPPLY OUTLET.
If checks are made inside the welding machine while it is live, this
may cause serious electric shock due to direct contact with live
, after a few
BASE parts and/or injury due to direct contact with moving parts.
______________________________________________________
- Inspect the welding machine regularly, with a frequency depending
on use and the dustiness of the environment, and remove the dust
deposited on the transformer, reactance and rectifier using a jet of
dry compressed air (max. 10 bar).
- Do not direct the jet of compressed air on the electronic boards;
these can be cleaned with a very soft brush or suitable solvents.
- At the same time make sure the electrical connections are tight and
check the wiring for damage to the insulation.
- At the end of these operations re-assemble the panels of the
welding machine and screw the fastening screws right down.
- Never, ever carry out welding operations while the welding machine
is open.
8. TROUBLESHOOTING
IN CASE OF UNSATISFACTORY FUNCTIONING, BEFORE
SERVICING MACHINE OR REQUESTING ASSISTANCE, CARRY
OUT THE FOLLOWING CHECK:
- Check that the welding current, which is regulated by the
potentiometer with a graduated amp scale, is correct for the diamter
and electrode type in use.
- Check that when general switch is ON the relative lamp is ON. If this
is not the case then the problem is located on the mains (cables,
plugs, outlets, fuses, etc.)
- Check that the yellow led (ie. thermal protection interruption- either
over or undervoltage or short circuit) is not lit.
- Check that the nominal intermittance ratio is correct. In case there is
a thermal protection interruption, wait for the machine to cool down,
check that the fan is working properly.
- Check the mains voltage: if the value is too high or too low the
welding machine will be stopped.
- Check that there is no short-circuit at the output of the machine: if
this is the case eliminate the incovenience.
- Check that all connections of the welding circuit are correct,
particularly that the work clamp is well attached to the workpiece,
with no interferring material or surface-coverings (ie. Paint).
- Protective gas must be of appropriate type (Argon 99,5%) and
quantity.
_______________(I)_______________
ATTENZIONE:
P R I M A D I U T I L I Z Z A R E L A S A L D AT R I C E L E G G E R E
ATTENTAMENTE IL MANUALE DI ISTRUZIONE!
SALDATRICI A FILO CONTINUO PER LA SALDATURA AD ARCO
MIG/MAG E FLUX, TIG, MMA PREVISTE PER USO INDUSTRIALE
E PROFESSIONALE.
Nota: Nel testo che segue verrà impiegato il termine "saldatrice" .
1. SICUREZZA GENERALE PER LA SALDATURA AD ARCO
L'operatore deve essere sufficientemente edotto sull'uso sicuro
della saldatrice ed informato sui rischi connessi ai procedimenti
per saldatura ad arco, alle relative misure di protezione ed alle
procedure di emergenza.
(Fare riferimento anche alla "SPECIFICA TECNICA IEC o CLC/TS
62081": INSTALLAZIONE ED USO DELLE APPARECCHIATURE
PER SALDATURA AD ARCO).
- Evitare i contatti diretti con il circuito di saldatura; la tensione a
vuoto fornita dal generatore può essere pericolosa in talune
circostanze.
- La connessione dei cavi di saldatura, le operazioni di verifica e
di riparazione devono essere eseguite a saldatrice spenta e
scollegata dalla rete di alimentazione.
- Spegnere la saldatrice e scollegarla dalla rete di alimentazione
prima di sostituire i particolari d'usura della torcia.
- Eseguire l'installazione elettrica secondo le previste norme e
leggi antinfortunistiche.
- La saldatrice deve essere collegata esclusivamente ad un
sistema di alimentazione con conduttore di neutro collegato a
terra.
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MANUALE ISTRUZIONE