Lincoln Electric NA-3S, Service Manual, Page: 40 / 110

OPERATING INSTRUCTIONS
B-11 B-11
NA-3 AND NA-4
WELDING WITH DC OR AC
CONSTANT CURRENT (CC)
MECHANICAL SETUP
1. Set the head position relative to the
work as required for the fixture,
application, and procedures.
2. Rotate the wire straightener until the
hand wheel faces the wire reel. This
is required to smoothly feed the
electrode into the straightener.
3. If using a K148 or K226 Contact
Assembly, rotate the assembly
relative to the direction of travel as
shown in Figure B.7.
4. The mount for standard 60 lb
(27.2 kg) electrode coils includes a
two-position brake assembly.
Generally, when submerged arc
welding, the brake should be left at
the inner position (nearest the wire
reel shaft.)
5. Load the wire reel or install the speed
drum or reel.
6. Fill the flux hopper with new or freshly
screened flux.
ELECTRICAL SETUP
1. If using a multi-process power source
(SAM, SAF, SA-800, DC-600,
DC-1000, or DC-1500), set the power
source for constant current (CC)
welding per the instructions in the
power source manual.
2. Set the wire feeder for constant
current (CC) welding.
3. Set the power source for the
electrode polarity [DC(+) or DC(-)]
specified by the procedures. Reverse
the NA-3 or NA-4 voltmeter and
ammeter leads if the polarity was
changed. If using the discontinued
solid state remote field control with a
motor-generator power source, be
sure to set the power source
and field
control to the same polarity
before
starting the power source. Opposite
polarity settings will blow the fuse in
the field control.
4. Depending on the procedures and
application, the following must be
decided:
a. Whether to use “hot” or “cold”
starting.
b. Whether to start the travel with
the “Start” button or the arc.
WORK PIECE
TRAVEL
NOZZLE
TRAVEL
CONNECTOR
TAB
CONTACT
PRESSURE
SPRING
K148 CONTACT
ASSEMBLY
CONTACT
SPRING
K226 CONTACT
ASSEMBLY
FIGURE B.7 – K148 AND K226 CONTACT ASSEMBLY POSITIONING.