Lincoln Electric LN- 25 IM10084 Operator's Manual page 33

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PRObLEMS
(SYMPTOMS)
Wire feed speed consistently oper-
ates at the wrong value. The speed
changes when the wire feed speed
knob is adjusted.
The wire feed speed stuck at 200-
300 in/min and there is no change
when the wire feed speed knob is
adjusted.
Variable or "hunting" arc.
When the trigger is pulled, the wire
feeds slowly.
Poor arc starts with sticking or
"blast-offs", weld porosity, narrow
and ropy looking bead.
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.
TROUbLESHOOTING
Observe all Safety Guidelines detailed throughout this manual
POSSIbLE
Output Problems
7. Incorrect tension arm pressure on
the drive rolls.
8. The spindle brake is too tight.
9. Worn drive roll.
1. The jumper lead for normal
speed/extra torque is connected
improperly.
2. The wrong gear is installed in the
wire drive.
3. The brushes on the motor are
worn.
1. The tachometer is connected
improperly.
2. The tachometer has failed.
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.
The Run-In switch is "ON"
1. Improper procedures or tech-
niques.
LN-25™ IRONWORKER
CAUSE
7. Adjust the tension arm per the
8. Verify the spool of wire moves
9. Replace the drive rolls if worn or
1. Properly connect the normal
2. Install the proper pinion gear in
3. Replace
1. Verify all of the tachometer leads
2. Replace the motor and tachome-
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.
Use the set-up Push-button to turn
Run-in OFF.
1. See "Gas Metal Arc Welding
CAUTION
RECOMMENDED
COURSE OF ACTION
Instruction Manual. Most elec-
trodes feed well at a tension arm
setting of "3".
with minimal effort.
filled with dirt.
speed/extra torque jumper.
the wire drive.
the motor/gearbox
assembly.
are properly connected.
ter assembly.
nections are tight and that the
cables are in good condition.
Clean/replace as necessary.
ed procedure.
the strike out to 3/8 to 1/2 inches.
Remove or block sources of
drafts.
Guide" (GS-100).
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