Saf-Fro DV 400 FW FEEDER Instruction De Securite D'emploi Et D'entretien page 5

1 - Welding system selector:
In position (2 stroke welding) press the torch button to
start welding, and release to stop.
In position (4 stroke welding) press the torch button to de-
liver gas; on release, wire feed and current are activated; press
again to stop wire feed and current and release to shut off the gas
supply.
In position (spot welding) the welder operates in timed
mode; press the torch button to start the welding phase, which
stops automatically after the time interval as set on the timer po-
tentiometer (Ref. 5 - Picture 1 Page 3.).
2 - Machine ON indicator lamp
3 - Machine overheating indicator lamp or defect on the water
cooling PCB.
4 - Wire feed speed control -potentiometer
5 - Spot welding time control potentiometer, from 0.3 to 10
seconds (operating only with selector (Ref. 1 - Picture 1 Page 3.)
set to position
6 - Wire feed motor acceleration time control potentiometer.
7 - Wire burn-off potentiometer. Time during which the welding
power is maintained after regular release of the torch button. In
practice, at the end of welding, if this time is too short, the wire re-
mains stuck in the bath or protrudes too far from the torch contact
tube; otherwise, if the control time is too long, the wire remains
stuck in the torch contact tube, often causing damage to the latter.
8 - Advance wire button (without "current")
9 - Gas output test button
10 - Euro torch connector
14 - Voltmeter
15 - Ammeter
16 - Cooling water delivery connection (blue)
17 - Cooling water return connection (red)
5.0 BASIC INFORMATION REGARDING MIG
WELDING
MIG WELDING PRINCIPLES
MIG welding is autogenous, i.e. it permits welding of pieces made
of the same metal (mild steel, stainless steel, aluminium) by fu-
sion, while granting both physical and mechanical continuity. The
heat required for melting is generated by an electric arc that
strikes between the wire (electrode) and the piece to be welded.
A shield gas protects both the arc and the molten metal from the
atmosphere.
6.0 CONNECTION AND PREPARATION OF
EQUIPMENT FOR WELDING
CONNECT WELDING ACCESSORIES CAREFULLY TO AVOID
POWER LOSS OR LEAKAGE OF DANGEROUS GASES.
Carefully follow the safety standards
N.B. DO NOT ADJUST SWITCHES during welding operations to
avoid damage to the equipment.
CHECK THAT GAS IS DELIVERED FROM THE NOZZLE AND
ADJUST FLOW BY MEANS OF THE PRESSURE REDUCER
VALVE.
CAUTION: SCREEN GAS FLOW WHEN OPERATING IN OUT-
DOOR OR VENTILATED SITES; WELDING OPERATIONS
MAY NOT BE PROTECTED DUE TO DISPERSION OF INERT
SHIELDING GASES.
BASIC INFORMATION REGARDING MIG WELDING
6.1 WELDING
1. Open the gas cylinder and regulate gas outlet flow as re-
quired. Fit the earth clamp on a part of the welding piece with-
out any paint, plastic or rust.
For optimal welding, keep the torch in the same direction as
the wire feed, as illustrated in figure.
2. Select the welding current by means of switches bear in mind
that the greater the welding thickness, the more power is re-
quired. The first switch setting is suitable for minimum thick-
ness welding.Also take into account that each setting
features a specific wire drive speed which can be selected by
means of adjustment knob (Ref. 4 - Picture 1 Page 3.).
6.2 CARBON STEEL WELDING
For MIG welding, proceed as follows:
1. Use a binary shielding gas (commonly a AR/CO2 mixture
with percentages ranging from 75-80% of Argon and from 20-
25% of CO2), or ternary mixtures such as AR/CO2/O2.
These gases provide welding heat and a uniform and com-
pact bead, although penetration is low. Use of carbon dioxide
(MAG) as a shielding gas achieves a thin and well-penetrat-
ed bead but ionisation of the gas may impair arc stability.
2. Use a wire feed of the same quality of that of the steel for
welding. Always use good quality wire; welding with rusty
wires can cause welding defects.
In general the applicable current range for wire use is:
- Ø wire mm x 100 = minimum Amps.
- Ø wire mm x 200 = minimum Amps.
Example: Ø filo 1.2 mm= minimum Amps 120 mm/maximum
Amps 240.
The above range is used with binary AR/CO2 gas mixtures
and with short-circuiting transfer (SHORT).
3. Do not weld parts where rust, oil or grease is present.
4. Use a torch suited to welding current specifications
5. Periodically check that the earth clamp pads are not dam-
aged and that the welding cables (torch and earth) are not cut
or burnt which could impair efficiency.
6.3 STAINLESS STEEL WELDING
MIG Welding of 300 series (austenitic) stainless steel must be car-
ried out with a shielding gas that has a high Argon content and a
small percentage of O2 to stabilise the arc. The most commonly
used mixture is AR/O2 98/2.
- Never use CO2 or AR/CO2 mixtures.
- Never touch the wire.
The filler material used must be of a higher quality than the base
material and the welding zone must be completely clean.
6.4 ALUMINIUM WELDING
To MIG weld aluminium, use the following:
1. 100% Argon shielding gas.
2. Filler wire with a composition suited to the base welding ma-
terial. To weld ALUMAN and ANTICORODAL use 3-5% sili-
4 EN
EN