5.3
WELDING STAINLESS STEEL
The welding machine must be prepared as for welding mild
steel with gas protection, but with the following differences:
- Reel of stainless steel wire compatible with the composition
of the material to be welded.
- Cylinder containing 98% ARGON + 2% 0
composition)
The recommended torch angle and welding direction are
shown in figure 6.
6
MAINTENANCE AND CHECKS
Maintenance must be performed by skilled personnel.
6.1
GENERAL NOTES
Turn off the welding machine and unplug the power cord from
• • • • •
the socket before each checking and maintenance operation.
Moving parts can cause serious lesions
• • • • •
Keep away from moving parts.
• • • • •
INCANDESCENT SURFACES can cause serious burns.
• • • • •
Let the unit cool before servicing.
• • • • •
Periodically remove any dust or foreign matter that may
• • • • •
have deposited on the transformer or diodes; to do so, use
a jet of clean, dry air.
When replacing the wire roller, make sure the groove is
• • • • •
aligned with the wire and corresponds to the diameter of the
wire used.
Always keep the interior of the gas nozzle clean to avoid
• • • • •
metal bridges created by welding dross between the gas
nozzle and the contact tip. Make sure the outlet hole of the
contact tip has not expanded excessively; if so, replace.
Strictly avoid striking the torch or allowing it to suffer violent
• • • • •
impact.
6.2
REPAIRING THE WELDING MACHINE
Experience has shown that many mortal accidents are
caused by repairs performed incorrectly. That is why it is just
as important to check a repaired welding machine carefully
and completely as it is for a new welding machine.
In addition, this protects the manufacturer from being held
liable for defects when the true fault lies elsewhere.
6.2.1 Instructions for performing repairs
After rewinding the transformer or inductance, the welding
• • • • •
machine must pass the applied voltage tests as indicated in
table 2 of paragraph 6.1.3 of the standard EN 60974.1 (CEI
(recommended
26.13). Compliance must be verified as specified in 6.1.3.
2
If no rewinding has been done, a welding machine that has
• • • • •
been cleaned and/or revised must pass an applied voltage
test with test voltage values equal to 50% of the values given
in table 2 of paragraph 6.1.3. Compliance must be verified
as specified in 6.1.3.
After rewinding and/or replacing parts, the no-load voltage
• • • • •
must not exceed the values given in paragraph 10.1 of EN
60974.1.
If the repairs have not been performed by the manufacturer,
• • • • •
repaired welding machines in which some components have
been replaced or altered must be marked in such a way that
the person who performed the repairs is clearly identifiable.
After making repairs, take care to re-order the wiring so
• • • • •
that there is certain insulation between the primary side
and the secondary side of the machine. Prevent the wires
from coming into contact with moving parts or parts that
heat up during operation. Replace all clamps as on the
Fig.6
original machine to prevent a connection from occurring
between the primary and secondary side if a conductor
accidentally breaks or disconnects.
6.3
TROUBLE
The welding machine
supplies limited current
Welding with a lot of
metal spatter
The wire jams or
entangles between the
drive rolls and the torch
infeed wire guide
No wire feed or irregular
wire feed
Porosity in the welding
seam
TROUBLESHOOTING GUIDE
PROBABLE CAUSE
Line fuse blown
Burnt out diode or diodes
Burnt out electronic board
Loosened torch or earth connec-
tions or any other electrical power
connections
Voltage adjustment switch
has a loose contact
Improper adjustment of
welding parameters
Insufficient grounding
Contact tip with wrong
diameter
Misalignment of the drive roll
groove
Obstructed or clogged liner
Drive roll with too large a
groove
Obstructed or clogged
liner
Wire holding roller not
completely tightened
Clogged contact tip
Insufficient shielding gas
Excess oxidation of the
edges to be welded
Gas nozzle partially or
completely clogged by
spatter
REMEDY
Replace line fuse
Replace
Replace
Tighten all connections
Replace the switch
Select the correct parame-
ters through the welding-
voltage switch and the wire-
speed adjustment poten-
tiometer
Check grounding
connections
Replace
Realign
Remove and clean
Replace the drive roll
Remove and clean
Tighten all the way
Replace
Increase gas delivery
Thoroughly clean the
edges with a metal brush
Remove and clean or
replace being careful not
to clog the gas outlets
11