Lincoln Electric PRECISION TIG 375 Service Manual page 11

A-5
3. Be sure the torch and work cable rubber coverings
are free of cuts and cracks that allow high frequency
leakage. Cables with high natural rubber content,
such as Lincoln Stable-Arc ® better resist high fre-
quency leakage than neoprene and other synthetic
rubber insulated cables.
4. Keep the torch in good repair and all connections
tight to reduce high frequency leakage.
5. The work terminal must be connected to a ground*
within ten feet of the welder, using one of the follow-
ing methods.
* A metal underground water pipe in direct contact
with the earth for ten feet or more.
* A 3/4" (19mm) galvanized pipe or a 5/8" (16mm)
solid galvanized iron, steel or copper rod driven at
least eight feet into the ground.
The ground should be securely made and the ground-
ing cable should be as short as possible using cable of
the same size as the work cable, or larger. Grounding
to the building frame electrical conduit or a long pipe
system can result in re-radiation, effectively making
these members radiating antennas. (This is not rec-
ommended.)
6. Keep all access panels and covers securely in place.
7. All electrical conductors within 50 feet (15.2m) of the
welder should be enclosed in grounded rigid metal-
lic conduit or equivalent shielding. Flexible helically-
wrapped metallic conduit is generally not suitable.
8. When the welder is enclosed in a metal building,
several earth driven electrical grounds (as in 5
above) around the periphery of the building are rec-
ommended.
Failure to observe these recommended installation
procedures can cause radio or TV interference prob-
lems and result in unsatisfactory welding performance
resulting from lost high frequency power.
INSTALLATION
INPUT AND GROUNDING CONNECTIONS
___________________________________________
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.
Remove the reconnect panel cover located near the
back of the left case side to reveal the reconnected
panel. Welder supply line entry provision is in the
case rear panel. Entry is through a 1.75 inch (44mm)
diameter hole in the case back. Appropriate supply
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 qualified electrician is recom-
mended.
1. Connect the terminal marked
nect panel) to an earth ground.
2. Connect the input leads to terminals marked L1
(U) and L2 (V) on the reconnect panel. Use a sin-
gle phase line or one phase of a two or three
phase line.
3. On multiple input line voltage welders, be sure the
reconnect panel is connected for the voltage being
supplied to the welder.
Failure to follow these instructions can cause
immediate failure of components within the
welder.
PRECISION TIG 375
WARNING
ELECTRIC SHOCK can kill.
* Turn the input power OFF at the
disconnect switch or fuse box
before working on this equip-
ment.
FIGURE A.1
(below the recon-
WARNING
A-5
CONNECT INPUT
VOLTAGE LEVEL