Section 4; Description Of Control Panel; Coated Electrode Welding; Tig Welding - USAG 998 140A Manual Del Usuario

All manuals and user guides at all-guides.com
SECTION 4 --- OPERATION

4.1 DESCRIPTION OF CONTROL PANEL

On the front panel one finds:
1. Current adjustment knob
2. Electrode and earth clamp cable connectors
3. Welding current LED indicator (ok if on)
4. AC power input fault (voltage outside the + - 10% of 220 V range) or overheating condition LED indicator (OK if off).

4.2 COATED ELECTRODE WELDING

This power supply is suitable for welding with all types of electrodes. For the cellulose ones (AWS 6010), only specific
power supply can be used, see the technical tables. Use electrode holder clamps in compliance with the safety standards and
without projecting tightening screws. Make sure that the main switch on the back is on 0 position or that main supply plug is
not inserted in main outlet then connect welding cables in accordance with polarity indications given by the electrode
manufacturer. The welding circuit should not be deliberately placed in direct or indirect contact with protection wire if not
on piece to be welded. If earthing is deliberately made on the work piece by means of protection wire, the connection must
be as direct as possible, with the wire having a section at least equal to the welding current return wire and connected to the
piece being worked on, in the same place as the return wire, using the return wire terminal or a second earth terminal
closely. All possible precautions must be taken in order to avoid stray currents. Check that the input supply voltage matches
the voltage indicated on the power supply technical specification tag.
Connect main supply cable: when mounting a plug make sure that its capacity is adequate and that the yellow-green wire of
the mains cable is connected to the earth plug pin. The capacity of the magnetothermic switch or the fuses in the mains
supply line should be higher than or equal to current I absorbed by the unit. The absorbed current I is determined by
1 1
reading the technical specifications on the unit as corresponding to the main supply voltage U . Any extension cord should
1
have a section adequate for the absorbed current I . Turn on the power supply with the main switch on the back of the unit.
1
WARNING: ELECTRIC SHOCK CAN KILL.
Do not touch live electric parts.
Do not touch weld output terminals when unit is energized.
Do not touch torch or electrode and earth clamp at the same time.
Set current according to the electrode diameter, welding position and type of joint to be welded. When finished welding
.
always remember to turn the main switch off and to remove electrode from electrode holder

4.3 TIG WELDING

This power supply is suitable for TIG welding stainless steel, iron and copper.
Connect earth cable wire to positive (+) pole of welding unit and connect terminal clamp to working piece as close as
possible to power supply, making sure there is a good electrical contact. Use proper TIG torch and connect power wire to
negative pole of welding unit. The welding circuit should not be deliberately in direct or indirect contact with protection
wire if not on piece to be welded. If earthing is deliberately made on the workpiece by means of protection wire, the
connection must be as direct as possible, with the wire having a section at least equal to that of the welding current return
wire and connected to the piece being worked on, in the same place as the return wire, using the return wire terminal or a
second earth terminal closely. All possible precautions must be taken in order to avoid stray current. Connect gas pipe to
pressure reducer output connected to an ARGON cylinder. Regulate gas flow adjusting the regulation knob on the torch
handle. Inside the torch handle a valve allows the gas flow to be shut. Use a 2% thoriated tungsten electrode having a
diameter chosen according the negative electrode direct current (Argon) value as follows:
up to 60A diam. 1 mm
60A to 180A diam. 1.6 mm
180A to 250A diam. 2,4 mm
The electrode tip should be prepared for welding according to procedure indicated hereafter. Check the main
supply voltage to match the voltage on the power supply technical specification tag. Connect main supply cable:
17