Tig Welding (Fig. C) - CEA ROCK 160 Manual De Instrucciones

WELDING THICKNESS (mm)
1,5 ÷ 3
3 ÷ 5
5 ÷ 12
≥ 12
Ø ELECTRODE (mm)
1,6
2
2,5
3,2
4
PART TO BE WELDED
The part to be welded must always be connected to earth in or-
der to reduce electromagnetic emission. Much attention must
be afforded so that the earth connection of the part to be weld-
ed 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 elec-
trode, 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.
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.
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
Table 3
Ø ELECTRODE (mm)
2
2,5
3,2
4
Table 4
CURRENT (A)
30 ÷ 60
40 ÷ 75
60 ÷ 110
95 ÷ 140
140 ÷ 200

TIG welding (Fig. C)

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 cylin-
der and open it.
• With the machine switched off:
- Connect the earth cable to the snap-on connector
marked + (positive).
- Connect the relative earth clamp to the workpiece or
to the workpiece support in an area free of rust, paint,
grease, etc..
- Connect the TIG torch power cable to the snap-on con-
nector marked - (negative).
2) Adjust the welding current using the potentiometer (Pos. 3,
Fig. A).
3) Adjust the process switch (Pos. 4, Fig. A) to TIG (switch le-
ver moved to the left-hand side).
4) Start the welding machine by selecting pos. "I" on the line
switch (Pos. 8, Fig. A).
5) The green LED (Pos. 1, Fig. A) indicates that the welding
machine is powered and ready to work.
6) Adjust the gas flow by manually turning the valve on the
TIG torch.
7) The "Lift" function strikes the arc when the TIG torch elec-
trode comes into contact with the workpiece and is then
removed (see Fig. D).
8) Carry out TIG welding.
FIG. D
11