8
SECTION 2
INSTALLATION
2.4 OUTPUT WELDING CONNECTIONS
Before making any connections to the power source
output terminals, make sure that all primary input
power to the power source is deenergized (off) at the
customer's disconnect switch.
A
.
MIG Setup
(see Figure 2-1).
This power source
is designed to provide MIG welding operating
characteristics only when the J2 control recep-
tacle is "vacant" (meaning no accessories are
plugged in) or, if the remote HC-3B or HC-4B
hand control is plugged in. The process switch
must be set in the CV-MIG position for conven-
tional wire feeders or in the DIGITAL-MIG (cen-
ter) position for Digimig/Digimatic controls. Ad-
ditionally, proper operation of the power source
depends on the use of copper output cables that
are insulated, of adequate size, in good condi-
tion, and properly connected to the machine
using the jack plug connectors provided with the
power source. It is recommended that only 4/0
welding output cable be used, regardless of
length and current, and that these cables be kept
as short as possible. (Total length including work
and electrode leads should not exceed 100 feet.
Beyond this distance, there will be performance
deterioration. Consult with the factory if you have
an application of this nature.)
Pay particular attention to high resistance in the
welding circuit; specifically, the work cable/circuit
and water-cooled torch cable. It is recommended
that the power source/wire feeder and workpiece
be placed as close together as possible to limit
resistance in the welding circuit. High resistance
in the welding circuit can cause performance
deterioration (loss of "heat" input, popping of
weld puddle, bushy arcs, etc.). Ensure the work
cable is large enough, kept as short as possible,
properly insulated, securely connected to the
workpiece, and that all connections are clean
and tightly secured. If a separate work circuit is
used (such as in mechanical fixturing, shipbuild-
ing, robot fixturing, etc.), make sure the work
circuit is secure and presents a low resistance
path to the flow of welding current. Also, the
power cable on a water-cooled torch is normally
subject to gradual deterioration and increased
resistance due to corrosion. This leads to poor
performance as described above.
To ensure good torch performance, periodically
replace the water-cooled power cable.
The welding output receptacles are located on
the front panel; one negative (-) and one positive
(+) receptacle. Two male plug connectors (P/N
950693) are supplied with the power source for
attachment to customer supplied 4/0 welding
cables (see Table 2-1 and Figure 2-1). This
power source is designed for conventional and
digital MIG applications using Direct Current
Reverse Polarity (DCRP) setup. In a DCRP
setup, the torch or electrode is positive (+), and
the workpiece is negative (-).
B
.
Stick/Scratch-Start TIG/ Arc Gouging Setup
(see Figure 2-3).
These processes require
constant current (cc) type curve characteristics
for proper operation. These characteristics are
only provided when one of the remote accesso-
ries (FC-5B, TC-2B) is plugged into the J2 recep-
tacle or when the remote HC-3B or HC-4B hand
control is connected to J2 and its process switch
is set in the CC-TIG/Stick position. Select the
desired welding mode, accessories, and polarity
as shown in figure 2-3. The output cables may be
connected for DCRP or DCSP; meaning that for
a DCRP setup, the electrode holder/torch is POS
(+) and the work is NEG (-); whereas for a
DCSP setup, the electrode holder/torch is NEG (-
) and the work is POS (+).
Regardless of your secondary welding cable setup
(DCRP or DCSP), in order to prevent electrical shock,
it is necessary that you connect the workpiece to an
approved electrical (earth) ground. The work cable
lead is not a ground lead. It is used to complete the
welding circuit between the power source and the
workpiece. This connection (at the workpiece) must
be made to a clean, exposed metal surface that is free
of paint, rust, mill scale, etc. A separate connection
is required to ground the workpiece to an approved
earth ground. The work cable should be the same
rating as the torch/electrode cable lead.
Proper operation of the power source depends to a great
extent on the use of copper output cables that are
insulated, adequately sized, in good condition and prop-
erly connected to the machine using the jack plug connec-
tors provided. It is recommended that the output cables
be kept as short as possible, placed close together, and
be of adequate current carrying capacity. The resistance
