Troubleshooting - Elettro CF MMA 770 Instruction Manual

or 2 mm; the lighting power of the spark will allow you to
see through the dark glass of the face - plate. Make sure
that the spark is exactly on the edges to be welded; now
keep the spark on in order to heat the piece to be welded
and make the electrode melt. To get this, move the hand
back regularly, evenly and slowly by 1 or 2 mm, as the
electrode, when melting, makes the distance from the
piece to be welded increase (see picture 7).
In order to get perfect weld beads make sure of the
following :
1) The lag floating on the weld pool shall never exceed
the electrode, otherwise the welding would be porous
(i.e. the evenness of the weld bead would be broken by
any voids);
2) The advancing speed shall be proportional to the
diameter of the electrode and the surface to cover;
3) The width of the weld bead shall be got by little and
even oscillating movements;
4) The welding current shall be nether neither poor nor
excessive.
In the first case a weld bead would be obtained which
shows a marked roundness upwards and a poor
penetration; in the second case the penetration would be
very deep and the bead would show a flat roundness.
The obstacles the beginner comes up against in the
welding are mainly the electrode sticking and piercing.
Sticking occurs when the welding current is poor or when
the electrode is brought too strongly in touch with the
piece. If the electrode sticks to the piece, do not try to
tear it out, but make an oscillating motion and at the
same time pull back.
Piercing or burning generally occurs on thin thickness
and is due to overheating of the piece; in this case we
recommend to carry out the welding at intervals.
3 MAINTENANCE AND CHECK UP
3.1 GENERAL NOTES
3.3 TROUBLE SHOOTING
Problem
•
The welding machine does not
supply current:
inoperative.
• The welding machine supplies a
feeble current.
•
The pilot light and the thermostat
light are alight, but the welding
machine is inoperative.
Possible cause
→ Switch on OFF position.
completely
→ Plug not correctly connected.
→ The input supply voltage is different
from the voltage required by the
machine.
→ The thermostat is open.
WARNING: ELECTRIC SHOCK CAN KILL.
Do not touch live electrical parts.
−
Turn off welding power source and remove input
−
power plug from receptacle before, maintenance,
servicing.
MOVING PARTS can cause serious injury.
Keep away from moving parts.
−
HOT SURFACES can cause severe burns
Allow cooling the unit before servicing.
−
3.2 WELDING MACHINE MAINTENANCE
Experience has shown that many fatal accidents
originated from servicing which had not been perfectly
executed. For this reason, a careful and thorough
inspection on a serviced welding machine is just as
important as one carried out on a new welding machine.
Furthermore, in this way manufacturer can be protected
from being held responsible for defects when the fault is
someone else.
3.2.1 Prescriptions to follow for servicing:
After rewinding the transformer or the inductance, the
−
welding machine must pass the voltage test applied
according to that indicated in table 2 of the EN
60974-1.
If no rewinding is done, a welding machine, which
−
has been cleaned and/or reconditioned, must pass a
voltage test applied with voltage values equal to 50%
of the values given in table 2 of EN 60974-1.
After rewinding and/or the replacements of parts, the
−
no -Load voltage should not exceed the values given
in 10.1 of EN 60974-1.
If the servicing is not done by the manufacturer, the
−
repaired welding
replacements or modifications of any component,
should be labelled in a way such that the identity of
the person having serviced is clear.
Switch to ON position.
Connect it properly.
Check it.
Await some minutes to have the
reset of the thermostat.
machines which underwent
Remedy
9