Lincoln Electric LN-7 GMA WIRE FEEDERS - Manual (Page 53)

E-2 TROUBLESHOOTING & REPAIR E-2
LN-7 & LN-7 GMA
Observe all Safety Guidelines detailed throughout this manual
If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely, contact your Local Authorized
Field Service Facility.
CAUTION
PROBLEMS
PROBLEMS
(SYMPTOMS)
POSSIBLE
CAUSE
RECOMMENDED
COURSE OF ACTION
Rough wire feeding or wire not feed-
ing but drive rolls are turning.
Variable or hunting arc.
1. Gun cable kinked and/or twisted.
2. Wire jammed in gun and cable.
3. Incorrect size or installation of
drive rolls and guide tubes.
4. Drive roll loose.
5. Gun cable dirty.
6. Worn drive rolls.
7. Electrode rusty and/or dirty.
8. Worn nozzle or cable liner.
9. Partially flashed or melted contact
tip.
10. Incorrect idle roll pressure.
11. Wire reel brake tension set too
high.
1. Worn and/or melted contact tip.
2. Worn work cable or poor work
connection.
3. Loose electrode connections.
4. Wrong polarity.
1. Inspect gun cable and replace if
necessary.
2. Remove wire from gun and cable -
feed in new wire. Note any
obstructions in gun and cable.
Replace gun and cable if neces-
sary.
3. Refer to Operation Section for
proper installation of drive rolls
and guide tubes.
4. Remove, clean, install and tighten.
5. Clean cable or replace liner.
6. Replace.
7. Replace.
8. Replace.
9. Replace contact tip.
10. Set idle roll pressure see
Operation Section of manual.
11. Tension should be just high
enough to prevent overrun.
1. Replace tip - remove any spatter
on end of tip
2. Inspect - repair or replace as nec-
essary.
3 Be sure electrode lead is tight, gun
cable tight in wire feeder contact
block, gun nozzle and gun tip tight.
4. Check connection at output studs
for polarity required by welding
process.