Mma Electrode Welding (Fig. B); Tig Welding (Fig. C) - CEA Project 1600 Manual De Instrucciones

Fig. B

MMA electrode welding (Fig. B)

Electrode welding is used to weld most metals (different types
of steel, etc.) using coated rutilic and basic electrodes with
diameters ranging from Ø 1.6 mm to Ø 4 mm.
1) Connecting the welding cables:
Disconnect the machine from the mains power supply and
connect the welding cables to the output terminals (Posi-
tive and Negative) of the welding machine, attaching them
to the clamp and earth with the polarity specified for the
type of electrode being used (Fig. B). Always follow the
electrode manufacturer's instructions. The welding cables
must be as short as possible, they must be near to one
another, positioned at or near floor level.
2) Adjust the welding current using the potentiometer (Pos. 3,
Fig. A).
3) Adjust the process switch (Pos. 6, Fig. A) to ELECTRODE
(switch lever moved to the right-hand side).
4) Start the welding machine by selecting position 1 on the
line switch (Pos. 7, Fig. A).
5) The white LED (Pos. 1, Fig. A) indicates that the welding
machine is powered and ready to work.
6) Carry out welding by moving the torch to the workpiece.
Strike the arc (press the electrode quickly against the metal
and then lift it) to melt the electrode, the coating of which
forms a protective residue. Then continue welding by
moving the electrode from left to right, inclining it by about
60° compared with the metal in relation to the direction of
welding.
PART TO BE WELDED
The part to be welded must always be connected to earth in
order to reduce electromagnetic emission. Much attention
must be afforded so that the earth connection of the part to be
welded does not increase the risk of accident to the user or the
risk of damage to other electric equipment.
When it is necessary to connect the part to be welded to earth,
you should make a direct connection between the part and the
earth shaft. In those countries in which such a connection is
not allowed, connect the part to be welded to earth using sui-
table capacitors, in compliance with the national regulations.
WELDING PARAMETERS
Table 3 shows some general indications for the choice of
electrode, based on the thickness of the parts to be welded.
The values of current to use are shown in the table with the
respective electrodes for the welding of common steels and
low-grade alloys. These data have no absolute value and are
indicative data only. For a precise choice follow the instruc-
tions provided by the electrode manufacturer.
The current to be used depends on the welding positions and
the type of joint, and it increases according to the thickness
and dimensions of the part.
2000HA28
10
WELDING THICKNESS (mm)
1,5 ÷ 3
3 ÷ 5
5 ÷ 12
>= 12
The current intensity to be used for the different types of wel-
ding, within the field of regulation shown in table 4 is:
• High for plane, frontal plane and vertical upwards welding;
• Medium for overhead welding;
• Low for vertical downwards welding and for joining small
pre-heated pieces.
Ø ELECTRODE (mm)
1,6
2
2,5
3,25
4
A fairly approximate indication of the average current to use in
the welding of electrodes for ordinary steel is given by the fol-
lowing formula:
I = 50 x (Øe – 1)
where:
I = intensity of the welding current
Øe = electrode diameter
Example:
for electrode diameter 4 mm
I = 50 x (4 –1) = 50 x 3 = 150A

TIG welding (Fig. C)

TIG welding melts the metal of the workpiece, using an arc
struck by a tungsten electrode.
The fusion bath and the electrode are protected by gas
(Argon).
This type of welding is used to weld thin sheet metal or when
elevated quality is required.
1) Connecting the welding cables:
• Connect one end of the gas hose to the gas connecter
on the TIG torch and the other end to the Argon cylinder
and open it.
• With the machine switched off:
- Connect the earth cable to the snap-on connector
marked + (positive).
Table 3
Ø ELECTRODE (mm)
2
2,5
3,25
4
Table 4
CURRENT (A)
30 ÷ 60
40 ÷ 75
60 ÷ 110
95 ÷ 140
140 ÷ 190