Saf-Fro PRESTO 220 VRD Instruction De Securite D'emploi Et D'entretien page 6

EN
1. Start without requiring high frequency.
2. Start without ruining the electrode tip at any current setting,
therefore there is no inclusion of tungsten inside the work-
piece (a phenomenon that occurs with stroke start).
ARC EXTINGUISHING: To exit the welding phase the operator
can use the conventional lift method or, alternatively, a new meth-
od that simulates the torch button.
This method, called "Fuzzy Exit" enables a downslope with-
out torch button to be obtained. During the welding phase the
operator only has to move away from the workpiece to start
a downslope. To interrupt the slope (without waiting the time
necessary for its closing) the operator only has to lift the arc
(like with the classic Tig Lift procedure). Downslope duration
can be displayed and modified by pressing the key 11.
10. WELDING PROCESS SELECTION KEY: press this key
(Rif.10 - Picture 1 Page 4.) to select the welding process
(MMA or LIFT TIG).
11. WELDING PARAMETER SELECTION KEY: press this key
(Rif.11 - Picture 1 Page 4.) to modify the welding parameters
associated with the process selected.
In MMA mode, press the key to sequentially access the dis-
play and possible modification, by means of the knob, (Rif.12
- Picture 1 Page 4.) of the HOT START and ARC FORCE
rate (Rif.5 - Picture 1 Page 4.).
Press the key to display the set HOT START percentage val-
ue. Operate the adjustment knob (Rif.12 - Picture 1 Page 4.)
to change the value between 0 and 99%.
Press the key again for display/adjustment rate of the ARC
FORCE key. To return to the display of current, wait a few
seconds or press the key again (Rif.11 - Picture 1 Page 4.).
In LIFT TIG mode, press the key to sequentially access the
display (and possible modification by means of the knob
(Rif.12 - Picture 1 Page 4.) of the current up/downslope time
(Rif.6 - Picture 1 Page 4.) .
Press to display the time associated with the current upslope.
Operate the adjustment knob (Rif.12 - Picture 1 Page 4.) to
change the value between 00 and 9.9 seconds.
Press the key again for display/adjustment of the current
downslope time. The logic that starts the slope when the op-
TYPES OF MALFUNCTIONING
WELDING FAULTS
The generator does not weld: the digital instrument
does not light up.
The generator does not weld: the display shows
"- - -".
During welding the output current suddenly stops,
the green LED goes off, the yellow LED lights up
and the display shows the message "thA".
Reduced welding power.
Excessive jets.
Craters.
Inclusions.
Insufficient penetration.
Sticking.
Blowholes and porosity.
Cracks.
In TIG the electrode melts.
MAINTENANCE
12. ADJUSTMENT KNOB (Rif.12 - Picture 1 Page 4.): this knob
NB: The generator has an antisticking device that disables the
power in case of output short circuit or sticking of the electrode,
thus allowing the electrode to easily detach from the workpiece.
This device cuts in when the generator is powered, hence also
during the initial test period, therefore any inclusion of load or
short circuit in this period is seen as an anomaly that causes dis-
abling of output power (the message "ScA" is displayed).
5.0
IMPORTANT: DISCONNECT THE POWER PLUG AND WAIT
AT LEAST 5 MINUTES BEFORE CARRYING OUT ANY MAIN-
TENANCE. MAINTENANCE MUST BE CARRIED OUT MORE
FREQUENTLY IN HEAVY OPERATING CONDITIONS.
Carry out the following operations every three (3) months:
1.
2.
3.
4.
5.
Carry out the following operations every six (6) months:
1.
2.
6.0
POSSIBLE CAUSES
The main switch is off.
Power cable interrupted (two or more phases
are missing).
Other.
Insufficient power supply voltage.
A phase is missing.
Other.
The thermal trip switch has cut-in due to an
overtemperature
(See duty cycles).
Output connection cables not connected cor-
rectly.
Welding arch too long.
Welding current too high.
Excessive Arc Force.
Rapid moving away of electrode on lifting.
Poor cleaning or distribution of passes. Faulty electrode movement.
High feed speed. Welding current too low.
Welding arc too short.
Current too low.
Wet electrodes. Long arc. Incorrect torch polarity.
Current too high. Dirty materials.
Incorrect torch polarity. Type of gas unsuitable.
5 EN
erator moves the torch away from the workpiece can be ex-
cluded by setting the slope time to "of" (the message "dof" is
displayed).
Prolonged pressing of the key brings the welding parameters
to values that are more appropriate for the process selected
(Default values).
is used to adjust the welding current and the value of param-
eters associated with the selected process.
MAINTENANCE
Replace any illegible labels.
Clean and tighten the welding terminals.
Replace damaged gas tubing.
Repair or replace damaged welding cables.
Have specialized personnel replace the power cable if dam-
aged.
Remove any dust inside the generator using a jet of dry air.
Carry out this operation more frequently when working in
very dusty places.
TYPES OF MALFUNCTIONING/ WELDING
FAULTS – CAUSES – REMEDIES
CONTROLS AND REMEDIES
Turn the main switch on.
Check and remedy.
Request a check by the Assistance Centre.
Check and remedy.
Check and remedy.
Request a check by the Assistance Centre.
Leave the generator on and wait for it to cool (10-15
minutes) until the protector is reset and the corre-
sponding yellow LED goes off.
Check the condition of the cables, make sure the
earth clamp is adequate and that it is applied on the
workpiece cleaned of any rust, paint or grease.
Wrong torch polarity, lower the current values.
Wrong torch polarity, lower the current values.
Lower the Arc Force rate.
Increase the set current value.