Red-D-Arc LN-25x Operator's Manual page 26

LN-25X™
Internal Controls Description
2 Step - Trigger Interlock Switch
The 2 Step - Trigger Interlock switch
changes the function of the gun trigger.
2 Step trigger operation turns welding
on and off in direct response to the
trigger. Trigger Interlock operation
allows welding to continue when the
trigger is released for comfort on long
welds.
Place the toggle switch in the DOWN
position for 2 Step operation or in the
UP position for Trigger Interlock
operation.
2 Step Trigger
2 Step trigger operation is the most common. When the gun
trigger is pulled, the welding power source energizes the
electrode output and the wire feeder feeds wire for welding. The
power source and wire feeder continue welding until the trigger is
released.
Trigger Interlock
Trigger Interlock operation provides for operator comfort when
making long welds. When the gun trigger is first pulled, the
welding power source energizes the output and the wire feeder
feeds wire for welding. The gun trigger is then released while the
weld is made. To stop welding, the gun trigger is pulled again,
and when it is released the welding power source output turns off
and the wire feeder stops feeding wire.
Caution: If the arc goes out while welding with trigger interlock
operation, the electrode output from the welding power source
remains energized and the wire feeder will continue to feed wire
until the gun trigger is again pulled and then released.
Cold Feed Pushbutton
When cold feeding, the wire drive
will feed electrode but neither the
power source nor the gas solenoid
will be energized. Adjust the speed
of cold feeding by rotating the WFS
knob. Cold feeding, or "cold
inching" the electrode is useful for
threading the electrode through the
gun.
Preflow, Burnback and Postflow Timer Kit
The Preflow, Burnback and Postflow Timer Kit gives control over
the shielding gas at the beginning and end of the weld and
prepares the end of the wire for the next arc start. Additional
shielding gas protection is often required when welding aluminum,
stainless steel or exotic alloys.
TRIGGER
INTERLOCK
2-STEP
Preflow Timer
The preflow timer range is OFF to 10 seconds. Preflow time is the
time delay from when the trigger is pulled to when the wire starts
to feed and is energized. Preflow is used to purge the welding
gun with shielding gas and helps to minimize porosity at the start
of the weld.
Burnback Timer
The burnback timer range is OFF to 0.25 seconds. The burnback
timer controls the additional amount of time the power source
output remains ON after the wire drive has stopped feeding wire.
Burnback adjustment prevents the wire from sticking to the weld
at the end of a weld and helps to condition the wire for the next
weld.
To set the burnback time, adjust the knob to approximately 0.03
seconds and then decrease or increase the time as desired.
Postflow Timer
The postflow timer range is OFF to 10 seconds. Postflow is the
time from when the power source output turns OFF until the
postflow timer expires. Use postflow to protect the weld while the
weld cools.
B-9
PREFLOW BURNBACK
MIN MAX MIN
0 SECS 10 SECS 0 SECS 0.25 SECS
OPERATION
POSTFLOW
MAX MIN MAX
0 SECS 10 SECS