PULSE WELDING
Some people have trouble getting used to the behavior
of the pulsing arc. The parameters programmed into
the Power Wave have been thoroughly tested for their
ability to deliver a sound weld with good appearance.
There are, however, a few things to keep in mind when
pulse welding.
Spatter levels are often very low with the pulse
welding process. Pulsing is often used to eliminate
cleaning operations necessary when using other weld-
ing processes.
Fume levels are sometimes lower with the pulsing
process.Whether or not you will get lower fume levels
depends on the pulsing programs used.Cer tain wave-
form characteristics are necessary to get low fume lev-
els. Unfortunately, low fume procedures are harder to
weld with than procedures designed to optimize the
welding process.
The pulsing process is not slower than other pro-
cesses.The process is sometimes less forgiving when
the arc gets on or ahead of the puddle.More attention
must be paid to the weld to avoid losing the puddle.
Speed is a matter of deposition rate. All things being
equal regarding the joint being welded, the speed will
depend on the wire feed speed. The travel speed is
maximized by maintaining a very short arc. Often the
process is “trimmed”down until the arc “crackles.”The
spatter increases slightly, but many of the advantages
of pulsing are retained.When welding steel, the Power
Wave is designed to run well in this region between
pulse and short arc.
The pulsing process greatly affects the heat input
to the workpiece.This can be a valuable tool for either
increasing or decreasing the heat input with a given
process.For instance, it is possible to greatly increase
the heat input when welding steel at high deposition
rates. On the other hand, it is possible to reduce the
heat input using the pulsing process.For example, heat
input is reduced greatly with some of the low current
stainless steel procedures using the processes pro-
grammed into the Power Wave.In all cases, the Power
Wave procedures have been checked for their ability to
deliver a sound weld. However, the fusion of the weld
metal into the workpiece may be affected. It is the
responsibility of the user to determine if the welds pro-
duced are suitable and sound.
The Power Wave is optimized for use with a 0.75”
(1.9 cm) stickout. The adaptive behavior is pro-
grammed to support a stickout range from 0.5”to 1.25”
(1.3 to 3.2 cm).In the low and high end of the wire feed
speed ranges of most processes, the adaptive behav-
ior may be restricted.This is a physical restriction due
to reaching the edge of the operating range for the
process. It is possible to achieve adaptive behavior for
longer stickout lengths.However, shielding gas is often
lost when the stickout is too long.
A longer electrical stickout is often used with the
puls-ing process at higher deposition rates. A long
stickout will increase the melt-off rate of the wire. In
pulse welding, like other wire welding processes, the
arc length is determined by the voltage setting. This
voltage is programmed at the factory for each process
and wire feed speed. It may be changed using the
Voltage setting on the wire feeder.
When adaptive processes are used,the voltage will
vary with stickout.The machine must change the volt-
age to keep a stable arc.It is very impor tant to recog-
nize this. “Actual”arc voltage when welding will vary
because the stickout will seldom be held at the nominal
0.75”(1.9 cm) value.
OVERLOAD PROTECTION

Thermal Protection

The Power Wave has thermostatic protection from
excessive duty cycles, overloads, loss of cooling, and
high ambient temperatures.When the power source is
subjected to any of the conditions mentioned above, a
thermostat will open.The yellow high temperature light
on the case front comes on. See Figure B.1 for loca-
tion. Machine output is disabled, and welding is not
possible until the machine is allowed to cool and the
High Temperature Light goes out.

Current Protection

The Power Wave is limited to producing 750 amps peak
current. If the average current exceeds 540 amps, the
peak current will automatically be cut back to 100 amps
until the average current decreases to 50 amps.
OPERATION
B-21 B-21
POWER WAVE 450