Description of the welding machine
The welding machine is a current transformer for manual arc welding using MMA coated
electrodes and TIG with a torch that strikes the arc on contact.
The welding machine is built using electronic INVERTER technology.
The delivered current is direct.
The electrical characteristic of the transformer is of the falling type.
This manual refers to a range of welding machines that differ in some of their characteristics.
Identify your model in Fig. 1.
Main parts Fig. 1
A) Power cable.
B) ON/OFF switch.
D) Welding current adjustment.
F) Thermal cutout signal.
H) Couplings for welding cables (Some welding machines have directly connected
cables).
J) Power supply indicator
Technical data
A data plate is affixed to the welding machine. Fig. 2 shows an example of this plate.
A) Constructor name and address.
B) European reference standard for the construction and safety of welding equipment.
C) Symbol of the welding machine internal structure.
D) Symbol of the foreseen welding process: D1: MMA welding; D2: TIG welding.
E) Symbol of the continuous current delivered
F) Input power required:
1˜ alternate single phase voltage, frequency F1: from electrical power supply; F2:
from motor generator
G) Level of protection from solids and liquids.
H) Symbol indicating the possibility to use the welding machine in environments
potentially subject to electric discharges.
I) Welding circuit performance.
U0V
Minimum and maximum open circuit voltage (open welding circuit).
I2, U2 Current and corresponding normalised voltage delivered by the welding
machine.
X
Duty cycle. Indicate how long the welding machine can work for and how
long it must rest for in order to cool down. The time is expressed in % on the
basis of a 10 minute cycle (e.g. 60% means 6 min. work and 4 min. rest).
A/V
Current adjustment field and corresponding arc voltage.
J) Power supply data.
U1
Input voltage (permitted tolerance: +/- 10%).
I1 eff Effective absorbed current.
I1 max Maximum absorbed current.
K) Serial number
L) Weight
M) Safety symbols: Refer to Safety Warnings.
-
Technical data for electrode holder** Fig.7
Other technical data. Image 2b.
Normal use at 20° C for 10 minutes
T) Usable electrode
U) Normalized current supplied by the welding machine
V) Welding service in 10 minutes. Indicates how long the welding machine can work
and how long it must be turned off in order to cool down. Time is expressed in a
percentage of 10 minutes.
Z) Number of electrodes that can be welded in 10 minutes.
** (This component may not be included with some models).
Connections to the mains must be made by expert or qualified personnel.
Make sure that the welding machine is switched off and the plug is not in the power
socket before carrying out this procedure.
Make sure that the power socket that the welding machine is plugged into is protected
by safety devices (fuses or automatic switch) and grounded.
The device must be connected only to a supply system, with an earthed 'neutral' lead.
Assembly and electrical connections
¾ Assembly the detached parts found in the packaging (Fig.5) **.
¾ Check that the electrical supply delivers the voltage and frequency corresponding to the
welding machine and that it is fitted with a delayed fuse suited to the maximum delivered
rated current (I2max) Fig. 3,1.
L
The requirements set out in the IEC/EN61000-3-12 standard do not apply to this
equipment. If this equipment is connected to low voltage power supply network, either
the installer or the user is responsible for checking that this can be done (consult the
distribution system operator if required).
L
In order to comply with the requirements set out in the EN61000-3-11 (Flicker) standard,
it is advisable to connect the welder to the supply network interface points having an
impedance lower than the reference Zmax = Fig.3,4.
¾ Power plug. The effective absorbed current "I1 eff" is indicated on the technical
plate of the welding machine, when it is used at maximum power. Connect the
welding machine to a normalized plug (2P+T per 1Ph) of capacity sufficient
to deliver maximum power. Fig 3,2. If a 16A plug is connected to the welding
machine, make sure that the effective "I1 eff" current required for the desired use is
adequate to the 16A plug capacity and the slow blow fuse of the system. Fig 3,2.
950669-00 26/07/17
Starting up
Connection to motor generators
Some welding machines may be powered by a motor generator (see symbol on data
plate). Make sure that this has a power of at least 6 kVA and does not deliver a voltage
greater than 270V.
Preparing the welding circuit MMA
¾ Connect the ground lead** to the welding machine and to the piece to be welded, as
close as possible to the point to be welded.
¾ Connect the cable with the electrode holder gripper** to the welding machine and mount
the electrode on the gripper. Refer to the electrode manufacturer's instructions concerning
connection and welding current.
L
In welding machines that deliver direct current, most of the electrodes are connected
to the positive attachment, and only some electrodes (such as Rutile coated ones) are
connected to the negative attachment.
Preparing the welding circuit TIG
¾ Connect the ground lead** to the welding machine and to the piece to be welded, as
close as possible to the point to be welded.
¾ Connect the TIG torch** power connector to the negative attachment on the welding
machine and mount the electrode. The torch must be fitted with a gas flow adjustment
valve.
¾ Connect the TIG torch gas pipe to the output of the pressure reducer mounted on an
ARGON protection gas cylinder.
L
The recommended sections (mm2) of the welding cable, based on the maximum
delivered rated current (I2 max), are shown in Fig. 3,3.
** (This component may not be included with some models).
Welding process: description of controls and signals
Once you have put the welding machine into operation, switch it on and carry out the
required adjustments.
Adjusting the welding current
Select the welding current depending on the electrode, the joint and the welding position.
Indicatively, the currents to be used with the different electrode diameters are listed in Fig. 4.
L
To strike the welding arc with the coated electrode, brush it onto the piece to be
welded and as soon as the arc is struck, hold it constantly at a distance equal to the
electrode diameter and at an angle of approximately 20 - 30 degrees in the direction
in which you are welding.
L
To strike the welding arc with the TIG torch, make sure that the protection gas valve
is open. With a rapid, sure movement, touch and then withdraw the electrode point
from the piece to be welded.
Thermal cutout signal "F"
The warning light switched on means that the thermal protection is running.
If the duty cycle "X" shown on the data plate is exceeded, a thermal cutout stops the
machine before any damage is caused. Wait for operation to be resumed and, if possible,
wait a few minutes more.
If the thermal cutout continues to cut in, the welding machine is being pushed beyond its
normal performance levels.
"Hot start"
The welding machine is fitted with an automatic device that facilitates the striking of the
arc, increasing the current only at that very moment.
"Antisticking"
The welding machine is fitted with an automatic device that interrupts the current a few
seconds after having detected that the electrode has stuck to the piece to be welded. In
this way the electrode will not overheat.
Recommendations for use
Only use an extension lead when absolutely necessary and providing it has an equal or
larger section to the power cable and is fitted with a grounding conductor.
Do not block the welder air intakes. Do not store the welder in containers or on shelving
that does not guarantee suitable ventilation.
Do not use the welder in any environment in the presence of gas, vapours, conductive
powders (e.g. iron shavings), brackish air, caustic fumes or other agents that could
damage the metal parts and electrical insulation.
L
The electric parts of the welder have been treated with protective resins. When used for
the first time, smoke may be noticed; this is caused by the resin drying out completely.
The smoke should only last for a few minutes.
Switch off the welder and remove the plug from the power socket before carrying out any
maintenance operations.
Extraordinary maintenance to be carried out by expert staff or qualified electrical
mechanics periodically depending on use. (Apply the rule EN 60974-4).
• Inspect the inside of the welder and remove any dust deposited on the electrical parts
(using compressed air) and the electronic cards (using a very soft brush and appropriate
cleaning products). • Check that the electrical connections are tight and that the insulation
on the wiring is not damaged.
6
Maintenance