Telwin MIG-MAG 220 A Manuel D'utilisation page 8

- Cut the end of the wire so that 10-15 mm protrude from the nozzle.
- Close the reel compartment door.
6. WELDING: DESCRIPTION OF PROCEDURE
SHORT ARC
The wire melts and the bead detaches as a result of the subsequent
short-circuits in the wire tip positioned in the weld pool (up to 200
times per second). The wire stick-out is normally between 5 and 12
mm.
Carbon steel and low-alloy steel
- Usable wire diameter:
- Usable gas:
Stainless steel
- Usable wire diameter:
- Usable gas:
Aluminium and CuSi
- Usable wire diameter:
- Usable gas:
Flux-core wire
- Usable wire diameter:
- Usable gas:
SHIELDING GAS
The shielding gas flow rate must be 8-14 l/min.
WELDING POWER ADJUSTMENT (FIG. C-3)
Adjusting the welding power according to the panel thickness
simultaneously influences the feeding speed and the amount of
current transferred to the filler wire.
Two different scales are available (FIG. C-5), which give an estimated
indication of the thickness that can be welded according to the wire
being used.
Having the arc length adjuster at the intermediate position
a good starting point for welding in different working conditions.
ARC LENGTH ADJUSTMENT (FIG. C-4)
Arc length adjustment establishes the highest or lowest temperature
ratio at the welding point. In the majority of cases, the basic setting is
optimal if the regulator is at the
If welding is too convex, the arc is too short or too cold. Use a longer
or hotter arc therefore, rotating the control clockwise.
If welding is concave, the arc is too long or too hot. To prevent
perforating the panels, rotate the control in an anticlockwise direction.
If necessary, the welding power can also be decreased.
NOTE: There is a label giving various thickness scales according to
the material and gas to be used in the reel space (Fig. F).
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).
0.6 - 0.8 mm
CO or Ar/CO mixes.
2 2
0.8 mm
Ar/O or Ar/CO (1-2%) mixtures
2 2
0.8 - 1.0 mm (0.8 mm for CuSi)
0.8 - 1.2 mm (140 A version)
0.8 - 0.9 mm (115 A version)
None
gives
intermediate position.
EXTRAORDINARY MAINTENANCE
EXTRAORDINARY MAINTENANCE MUST ONLY BE CARRIED
OUT BY TECHNICIANS WHO ARE EXPERT OR QUALIFIED IN
THE ELECTRIC-MECHANICAL FIELD, AND IN FULL RESPECT
OF THE IEC/EN 60974-4 TECHNICAL DIRECTIVE.
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 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
Ar 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.
- After having carried out maintenance or repairs, restore the
connections and wiring as they were before, making sure they do
not come into contact with moving parts or parts that can reach high
temperatures. Tie all the wires as they were before, being careful
to keep the high voltage connections of the primary transformer
separate from the low voltage ones of the secondary transformer.
Use all the original washers and screws when closing the casing.
8. TROUBLESHOOTING
IN CASE OF UNSATISFACTORY FUNCTIONING, BEFORE
SERVICING MACHINE OR REQUESTING ASSISTANCE, CARRY
OUT THE FOLLOWING CHECK:
- 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 and quantity.
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