Lincoln Electric POWER FEED 25M NNS Operator's Manual page 54

POWER FEED™ 25M NNS
PROBLEMS
(SyMPTOMS)
Variable or "hunting" arc.
Poor arc starts with sticking or
"blast-offs", weld porosity, narrow
and ropy looking bead.
The wire feed speed/amperage and
voltage/trim display work during pre-
set but show nothing during welding.
If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely, contact your
Local Lincoln Authorized Field Service Facility for technical troubleshooting assistance before you proceed.
Observe all Safety Guidelines detailed throughout this manual
POSSIBLE
Output Problems
1. Wrong size, worn and/or melted
contact tip.
2. Worn work cable or poor work
connection.
3. Wrong polarity.
4. The gas nozzle is extended
beyond the contact tip or the wire
stickout is too long.
5. Poor gas shielding on processes
requiring gas.
1. Improper procedures or tech-
niques.
1. The software in the POWER
FEED™ 25M NNS must be
upgraded.
CAUSE
1. Replace the contact tip.
2. Verify all work and electrode con-
3. Adjust polarity to the recommend-
4. Adjust the gas nozzle and shorten
5. Check gas flow and mixture.
1. See "Gas Metal Arc Welding
1. Contact the local authorized
CAUTION
E 4
TROUBLE SHOOTING
RECOMMENDED
COURSE OF ACTION
nections are tight and that the
cables are in good condition.
Clean/replace as necessary.
ed procedure.
the stickout to 3/8 to 1/2 inches.
Remove or block sources of
drafts.
Guide". (GS-100).
Lincoln Field Service Shop.