Everlast PowerMTS 251Si Operator's Manual page 23

Section 2
gun when it is connected.
19. Negative Polarity Connector (-). This front
mounted connector terminal is a standard 35
series DINSE style connector. It provides nega-
tive polarity output. When using stick mode, con-
nect the cable from the work clamp to this termi-
nal for most applications. When using Flux-core
or dual shield, change polarity inside the ma-
chine by changing the buss-bar position, unless
the wire manufacturer states to use electrode
positive. Do not use this connection for most Flux
-core and Dual shield wires that require Elec-
trode negative polarity (Straight Polarity) Con-
nect the work clamp to this side while in MIG/
Stick mode. Connect the TIG torch to this side
while in TIG mode. HINT: Don't forget to
change the work clamp when changing to TIG or
from TIG to the other processes. Failing to do
so will result in erratic operation of the selected
process. This is a common issue that prompts
many to call technical support.
Additional features located within the Sequencer.
1. MIG Inductance. (Located on the far left side of
the Sequencer Graph.) Varies the current-rise
time while welding after the arc shorts to the
puddle during the short-circuit transfer process.
This affects the actual physical point where the
current has risen sufficiently to melt back the
wire, subsequently pinching off and depositing in
the puddle. The physical point at which the wire
has burned back is considered the "pinch point"
of the arc. This is where the wire will melt back
to before transferring the wire back to the pud-
dle to once again short out. To put it in more
practical terms, the user will see that the wire is
sticking out longer or shorter from the MIG torch
before it burns away, depending upon the exact
setting. This controls spatter, penetration and
bead profile. When the arc force knob is rotated
from one extreme to the other, the operator will
observe that the arc is more stiff at one end or
more fluid at the other end. Bead profile chang-
es will occur as well. A stiffer arc will produce a
deeper but more narrow profile. A fluid arc will
produce a wider, shallower weld, usually with an
improved bead appearance and less spatter. Arc
force control is also known as inductance con-
trol, slope or wave form control (MIG). By
changing the level of inductance, the user can
fine tune the arc performance so the welder re-
sponds in a manner that the user is accustomed
Setup Guide and Component Identification
to with other brands of machines. The arc sound
will also change as the arc force is adjusted, going
from a relatively high pitched whine to a frying
sizzle. All MIGs, regardless of brand, without an
adjustable arc force, do have some fixed level of
inductance, though not all are set at the same lev-
el. A user can either adjust the inductance to have
a familiar feel, or to improve arc behavior whenev-
er welding position or condition change. This con-
trol is primarily useful for short circuit welding and
has limited value in Axial Spray. While using many
types of flux core or dual shield, manufacturers will
often specify a setting of "0", though "0" is a rela-
tive value, and inductance cannot be completely
eliminated. In MIG, excessive or too little amounts
of inductance can create a violent arc or an unsta-
ble one, so be careful about selecting too much or
too little. A good starting point is around 60 or
70%. Make gradual, changes to fine tune the in-
ductance. Giant swings will make other parame-
ters harder to dial in properly as the inductance
can greatly affect the feel of welding arc in both
modes. Set the amount of inductance to the ap-
proximate level desired before tuning other pa-
rameters (whether you are in standard or pulse
modes). Do not attempt to further alter induct-
ance until all other parameters are fine tuned as
much as possible. After Volt and Amp adjustments
are tuned to the best setting you can achieve, then
fine tune the inductance level as the final stage of
MIG adjustment.
2. Burn Back Timer Control. (Located on the far right
side of the Sequencer Graph.) The burn back timer
controls the amount of time that the arc stays en-
gaged after the trigger is released and the wire
feeding stops. This is to help reduce wire stick out
and reduce the need to trim the wire before
starting another weld. This also serves to prevent
the wire from sticking in the weld puddle once the
arc is stopped. For best results this should be used
with the Post flow feature so that the wire does
not become oxidized during the burn back phase. If
too much burn back is used, the wire may burn
back up into the tip. Increase burn back by only a
couple tenths of a second at a time to prevent over
adjusting the burn back and destroying the contact
tip. Generally burn back control will produce con-
sistent results and increase production. Different
wire diameters and feed rates will change the burn
back time requirement. Keep in mind burn back
control is another tool designed to help increase
quality and ease of welding. Time can be set at
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