USAG 998 140A, Instruction Manual

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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
1
absorbed by the unit. The absorbed current I
1
is determined by dividing by 1.6 the value stated on the table. Any extension
cord should have a section adequate for the absorbed current I
1
. Set welding current based on the weld to be performed then
adjust the gas flow with knob on torch handle. Start the arc, by contact, with a quick scratch on the surface to be welded.
CAUTION do not use commercial ignition devices. The TIG torch is designed in such a way that using the valve on the
torch body the gas flow can continue after the weld is performed to protect the electrode while it is still hot. After the proper
amount of time /few seconds) the gas flow can be stopped by shutting the valve on the torch handle. Once welding is
finished the unit is to be turned off and the gas cylinder valve is to be closed.
4.3.1 ELECTRODE PREPARATION
It is necessary to use special attention when preparing the electrode tip grinding it so as to obtain vertical makings as shown
in figure (see in schemas section): CAUTION: HOT FLYING METAL PARTICLES can injure personnel, start fires and
damages equipment. TUNGSTEN CONTAMINATION can lower weld quality. Shape tungsten electrode tip only on
grinder with proper guards in a safe location wearing proper face, hand and body protection.
Shape tungsten electrode tip on a fine grit, hard abrasive wheel used only for tungsten shaping. Grind the end of the
tungsten electrode to a taper for a length of 1.5 to 2 electrode diameters
.