Input And Grounding Connections - Lincoln Electric PRECISION TIG 275 Operator's Manual

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PRECISION TIG 275
5. The work terminal must be connected to a ground within ten
feet of the welder, using one of the following methods:
• A metal underground water pipe in direct contact with the
earth for ten feet or more.
• A 3/4" (19 mm) galvanized pipe or a 5/8" (16 mm) solid
galvanized iron, steel or copper rod driven at least eight
feet into the ground.
The ground should be securely made and the grounding cable
should be as short as possible using cable of the same size as
the work cable, or larger. Grounding to the building frame elec-
trical conduit or a long pipe system can result in re-radiation,
effectively making these members radiating antennas. (This is
not recommended).
6. Keep all access panels and covers securely in place.
7. All electrical conductors within 50 feet (15.2 m) of the
welder should be enclosed in grounded rigid metallic conduit
or equivalent shielding. Flexible helically-wrapped metallic
conduit is generally not suitable.
8. When the welder is enclosed in a metal building, several
good earth driven electrical grounds (as in 5 above) around
the periphery of the building are recommended.
Failure to observe these recommended installation procedures
can cause radio or TV interference problems and result in unsat-
isfactory welding performance resulting from lost high frequency
power.

INPUT and GROUNDING CONNECTIONS

ELECTRIC SHOCK can kill.
•
Turn the input power OFF at the discon-
nect switch or fuse box before working
on this equipment
_______________________________________
Be sure the voltage, phase, and frequency of the input power is
as specified on the rating plate, located on the rear of the
machine.
Fuse the input circuit with the recommended super lag fuses or
delay type1 circuit breakers. Choose an input and grounding
wire size according to local or national codes or use Section A-
2. Using fuses or circuit breakers smaller than recommended
may result in "nuisance" tripping from welder inrush currents
even if not welding at high currents.
Unbalanced AC TIG welding draws higher input currents than
those for Stick, DC TIG, or Balanced AC TIG welding. The welder
is designed for these higher input currents. However, where
unbalanced AC TIG welding above 185 amps is planned, the
higher input currents require larger input wire sizes and fuses per
Section A-2:
Remove the reconnect panel cover located near the back of the
left case side to reveal the reconnect panel. Welder supply line
entry provision is in the case rear panel. Entry is through a 1.75
inch (44 mm) diameter hole in the case back. Appropriate sup-
ply line strain relief clamp is provided by installer. (See Figure
A.1)
CONNECT INPUT
POWER LEADS
CONNECT INPUT
GROUND LEAD
All connections should be made in accordance with all local
codes and national electrical codes. Installation by a quali-
fied electrician is recommended.
A 4
INSTALLATION
WARNING
.
FIGURE A.1
CONNECT INPUT
VOLTAGE LEVEL