Thermal Arc 400 GTSW AC/DC, Operating Manual

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INTRODUCTION vi
come electrically hot - a dangerous condition that may cause
potentially fatal electric shock.
Before welding, check ground for continuity. Be sure conductors
are touching bare metal of equipment frames at connections.
If a line cord with a ground lead is provided with the equipment
for connection to a switchbox, connect the ground lead to the
grounded switchbox. If a three-prong plug is added for connec-
tion to a grounded mating receptacle, the ground lead must be
connected to the ground prong only. If the line cord comes with
a three-prong plug, connect to a grounded mating receptacle.
Never remove the ground prong from a plug, or use a plug with
a broken off ground plug.
Fully insulated electrode holders should be used. Do not use
holders with protruding screws.
Fully insulated lock-type connectors should be used to join
welding cable lengths.
Frequently inspect cables for wear, cracks and damage. Replace
those with excessively worn or damaged insulation to avoid
potentially fatal electric shock from bared cable. Cables with
damaged areas may be taped to give resistance equivalent to
original cable.
Keep cables dry, free of oil and grease, and protected from hot
metal and sparks.
Terminals and other exposed parts of electrical units should have
insulating covers secured before operation.
For equipment with output ON/OFF control (contactor): Weld-
ing power sources for use with gas metal arc welding (GMAW),
gas tungsten arc welding (GTAW) and similar processes nor-
mally are equipped with devices that permit ON-OFF control of
the welding power output. When so equipped the electrode wire
becomes electrically hot when the power source switch is ON and
welding gun switch is closed. Never touch electrode wire or any
conducting object in contact with electrode circuit unless the
welding power source is OFF.
For equipment without output ON/OFF control (no contactor):
Welding power sources used with shielded metal arc welding
(SMAW) and similar processes may not be equipped with weld-
ing power output ON-OFF control devices. With such equipment
the electrode is electrically hot when the power switch is turned
ON. Never touch the electrode unless the welding power source
is off.
Safety devices such as interlocks and circuit breakers should
never be disconnected or shunted out.
IMPORTANT SAFETY PRECAUTIONS (continued)
Electric Shock
(continued)
Electrode