Lincoln Electric NA-3S, Service Manual, Page: 43 / 110

OPERATING INSTRUCTIONS
B-14 B-14
NA-3 AND NA-4
When using an open arc process, it is
necessary to use correct eye, head, and
body protection.
9. Make a test weld and adjust the wire
feeder “Voltage Control” and “Current
Control” until the meters indicate the
output specified by the procedure.
10. Make several test welds and readjust
the starting and stopping controls in
the following order:
a. Set the “Inch Speed” control for
optimum arc striking. If using long
stickout techniques, see the
IM278 operating manual on using
the Linc-Fill extension.
b. If installed, adjust the “Start
Controls” to set the welding pro-
cedures during the first 0 to 3
seconds of welding in order to
provide the bead size, penetra-
tion, or other factors as needed
for the application.
c. If installed, adjust the “Crater
Controls” to set the welding
procedures during the first 0 to 3
seconds after the “Stop” button is
pressed in order to provide the
bead size or to fill the crater as
needed for the application.
d. Set the “Contactor and Electrode
Back Up Time Delay” to provide
the stopping characteristics
needed.
STARTING AND
STOPPING SEQUENCES
AVAILABLE STARTING
SEQUENCES
The NA-3N utilizes “hot start” arc striking.
The NA-3s and NA-4 can use either “hot
start” or “cold start” arc striking without any
rewiring.
Hot Starting
1. With the electrode not touching the
work, press the “Start” button.
2. The electrically “hot” electrode inches
down at the preset inching speed.
3. When the electrode touches the work,
the arc strikes and the circuit
automatically switches from inching to
welding wire feed speed.
Use either the standard “on-the-fly” travel
starting or rewire the controls for “standstill”
travel starting as described in the Setting
Travel Starting and Stopping section.
Cold Starting
Cold starting is recommended primarily for
submerged arc welding with a constant
current power source when the weld must
start at a precise location. It can be used on
DC-600 and DC-1500 power sources.
1. Inch the electrode down with the “Inch
Down” button. When it touches the
work, inching automatically stops and
the flux valve opens (the switch on
the flux hopper must be “On”).
2. Press the “Start” button to begin the
weld.
Optional Start Controls PC Board
This starting sequence is recommended for
applications in which penetration, bead size,
and other characteristics must be carefully
controlled at the start. It is required when
using Linc-Fill long stickout procedures.
The starting sequence is as described in the
“hot starting” procedure except that when the
arc strikes, the machine welds at the
current* and voltage set by the start controls
panel until the time set on the “Time in
Seconds” control elapses. The circuit then
automatically switches to the welding current
and voltage. Actual settings depend on
application requirements.
SETTING TRAVEL STARTING
AND STOPPING
When shipped, all models are connected so
travel starts when the “Start” button is
pressed and stops when the “Stop” button is
pressed. Standard machines can be
connected for a variety of starting and
stopping sequences.
*With the NA-4 and discontinued AC-1000 or AC-750
combination, the current is not adjustable.
WARNING