Therefore, following steps must be followed:
A) The contact tip hole must be kept free of dirt or oxidation.
B) After lengthy welds, spatter can easily accumulate on the
contact tip and prevent the wire from being fed. The contact
tip must be cleaned regularly and if necessary it must be
replaced.
C) The contact tip must always be screwed tightly on to the
body of the torch. The thermal cycles which the torch under-
goes during operation may loosen the contact tip which, in
turn, may cause the torch body and nozzle to overheat or
cause unsteady wire feed.
The Wire Liner is an important part that must often be
checked since, during normal operations, the wire can depo-
sit copper dust or tiny metal shavings in the lining. Periodically
clean the liner and the gas line with a jet of dry, compressed
air. Wire liners are exposed to continual wear and therefore
they must be replaced after a certain period of time.
Wire feed motor. Periodically clean the wire feed assembly
and the drive rolls from any rust or metal shavings due to the
feeding of the wire. A periodic check of all the components
of the wire feed assembly, spool holder, drive rolls, wire liner
and the contact tip is recommended.
8 TROUBLESHOOTING
PROBABLE CAUSE
TROUBLE
Limited electric
A phase is missing
output
A line fuse is burnt
Wrong connection on the
voltage changer terminal
board
The rectifier diode are burnt
Loosened torch or
ground connections
Welding regulation commuta-
tor has an uncertain contact
Trasformer wire interrup-
ted on the commutator
Welding with a lot
Wrong adjustment of the
of metal spatter
welding parameters
Wire advancing unproperly
Insufficient grounding
Wire not
Wire roller with too wide
advancyng or
groove
advancyng unpro-
Obstructed or clogged liner
perly
Loose wire pressing roller
Coil reel friction too tight
Current nozzle clogged
The wire jams or
Wrong current nozzle dia-
entangles between
meter
the drive rolls and
Wrong roller groove align-
the torch infeed
ment
wire guide
Obstructed or clogged
sheath
Note: All repair work must be done by qualified person-
nel.
Disconnect the power input cable from the mains supply
before replacing cables or before removing the unit covers.
The machine is equipped with a thermostat that shuts the
machine down when the power source overheats. After the
thermostat intervenes, let the power source cool down for
several minutes before resuming welding operations.
The troubleshooting table lists troubles, causes and reme-
dies for those troubles that occur most commonly.
Experience has shown that many fatal accidents originated
from servicing improperly executed. For this reason, a care-
ful 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 producers can be protected from
being held responsible for defects stemming from repairs
not carried out by the manufacturer.
9.1 Prescriptions to follow for servicing
• After rewinding the transformer or the inductance, the wel-
ding machine must pass the applied-voltage test in accor-
dance with indications in table 2 of 6.1.3 of the EN 60974.1
standard (CEI 26.13).
Conformity must be checked as specified in 6.1.3.
REMEDY
• If no rewinding is done, a welding machine which has
Check the phase of the
feed line and/or the remo-
been cleaned and/or reconditioned must pass an
ve control switch contacts
applied-voltage test with voltage values equal to 50% of
Replace it
the values given in table 2 of 6.1.3. Conformity must be
Check the terminal board
checked as specified in 6.1.3.
connections by following
• After rewinding and/or the replacement the no-load
the plate scheme
voltage shall not exceed the values given given in 10.1
Replace the rectifier
of EN 60974.1.
Tighten all connections
l If the servicing is not done by the manufacturers, the repai-
red welding machines which underwent replacements or
Replace the commutator
modifications of any component, shall be marked in a
way such that the identity of the person having serviced
Unscrew the commutator
it is clear.
contact, remove the wire
• After making repairs, take care to re-order the cables so
insulation and put it under
that there is sure to be insulation between the primary and
the contact
secondary sides of the machine. Make sure that the wires
Select the correct parame
ters through the welding-
cannot come into contact with moving parts or parts that
voltage switch and the
heat during operation. Replace all clamps in their original
wire-speed adjustment
positions on the machine, to prevent a connection between
potentiometer
the primary and secondary circuits if a conductor acciden-
Uncorrect sheath diam.
tally breaks or disconnects.
Check grounding connec-
tions
Replace roller
Extract it and clean
Tighten it
Loosen and adjust it
Replace it
Replace it
Align it
Remove and clean
9 Welding machine servicing
11