Use Of Engine-Generators For Input Power; Grounding; Welding Leads - Thermal Arc ULTRA FLEX 350 Owner's Manual

430429-465
INSTALLATION
For Single Phase Connection:
1. Connect the BLACK and WHITE wires to the
AC power source.
2. Connect the GREEN wire to the power system
safety GROUND.
For Three Phase Connection:
1. Connect the RED, WHITE, and BLACK wires
to the AC power source.
2. Connect the GREEN wire to the power system
safety GROUND.
DANGER: ELECTRIC SHOCK
CAN KILL. Open the discon-
nect switch, or breaker, and
determine that no voltage is
present, before connecting
wires between welding ma-
chine and power supply.
CAUTION: The method of installation,
conductor size, and overcurrent protec-
tion shall conform to the requirements
of the local electrical code, the National
Electrical Code, or other national codes,
as applicable. All installation wiring and
machine reconnection shall be done by
qualified persons.
WARNING: Never connect the
safety ground screw to one of
the three line phases. This would
represent a serious electrical
shock hazard. The wiring to this
machine should be performed
by a qualified person only.
Use Of Engine-Generators For
Input Power
This welding power source may be powered by
engine driven generators. The generator must have
an adequate output power rating (20KVA minimum)
to power the unit. Make sure that the generator's
output voltage, frequency and phase ratings are
correct by checking the nameplate of the generator
or by measurement by a qualified electrician. To
connect the welding machine to the generator follow
the instructions in "Connecting the Welding Machine
to Line Voltage."
4-2
The generator used for power should have good
voltage and frequency regulation. If the generator's
output voltage or frequency (engine speed) varies
excessively with load, this may cause the protection
circuits for high or low line voltage to shut down the
welding machine and display a fault code. If this
happens frequently, then the generator output regu-
lation is not satisfactory to use as a power supply
for this welding machine.

Grounding

The frame of this welding machine should be
grounded for personnel safety, and to assure op-
eration of the overcurrent protection. The grounding
method, and the equipment grounding conductor
size and type shall conform to local and national
codes.
For the National Electrical Code, the equipment
grounding conductor shall be green, green with a
yellow stripe, or bare.
If flexible power cable is used, use a cable assem-
bly which includes the equipment grounding con-
ductor. If metallic armored cable or conduit is used,
the metal sheathing or conduit must be effectively
grounded per local and national codes.
Rubber-tire mounted equipment shall be
grounded to conform to local and national codes.
The grounding assists in providing protection
against line voltage electrical shock and static
shock. The grounding serves to discharge the static
electric charge which tends to build up on rubber-
tire mounted equipment. This static charge can
cause painful shock and lead to the erroneous
conclusion that an electrical fault exists in the equip-
ment.
If a system ground is not available, consult the
electrical code enforcement body for instructions.
The welding machine should be connected to an
adequate driven ground rod, or to a water pipe that
enters the ground not more than 10 feet (3 meters)
from the machine.

Welding Leads

Connect the welding leads to the output terminals
of the power source. Selection of the proper size of
welding leads should be based upon both the rated
ampacity of the wire as well as the voltage drop on
the cable. For Pulsed-GMAW welding, it is often
more important to size the welding leads for voltage
drop. If the voltage drop is excessive on the leads,
the power source will have difficulty producing the
peak pulse current with the correct voltage at the
February 28, 2000