Lincoln Electric IM475 MAGNUM 550 GUN & CABLE - Manual (Page 20)

E-2 TROUBLESHOOTING E-2
MAGNUM® 550
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 Lincoln Authorized Field Service Facility for technical troubleshooting assistance before you proceed.
CAUTION
PROBLEMS
(SYMPTOMS)
POSSIBLE
CAUSE
RECOMMENDED
COURSE OF ACTION
Drive rolls turn, but wire will not feed or
wire feeding is rough.
Variable or “hunting” arc.
Poor arc striking with sticking or “Blast-
offs”, weld porosity, narrow and ropy
looking bead, or electrode stubbing into
plate while welding.
Tip seizes in diffuser.
a. Gun cable kinked and/or twisted.
b. Wire jammed in gun and cable.
c. Incorrect drive rolls and guide tubes.
d. Gun cable liner dirty.
e. Worn drive rolls.
f. Electrode rusty and/or dirty.
g. Worn or improper size cable liner.
h. Partially flashed, melted, or improper
size contact tip.
i. Incorrect diffuser.
a. Contact tip worn or incorrect size.
b. Worn or undersize ground cables or
poor ground connections.
c. Loose electrode connections.
a. Improper procedures or techniques.
b. Improper gas shielding.
a. Tip overheating due to prolonged or
excessive high current and/or duty
cycle welding.
a. Keep as straight as possible. Inspect
cable and replace if necessary.
b. Remove wire from gun and cable -
feed in new wire. Note any obstruc-
tion. Replace liner if necessary.
c. Be sure the wire diameter being used
is stamped on drive rolls and guide
tubes. Replace if necessary.
d. Clean liner or replace.
e. Replace or reverse split drive roll
type.
f. Replace the electrode if it is rusty.
g. Replace cable liner.
h. Replace the contact tip.
i.
Be sure diffuser size is correct for the
electrode being used.
a. Replace contact tip.
b. Inspect - repair or replace as neces-
sary.
c. Be sure the following connections are
tight: electrode cable to wire feeder
and power source, work cable to
power source and work, gun cable to
wire feeder contact block, gun nozzle
to body, and contact tip to nozzle.
a. See “Gas Metal Arc Welding” (GS-
100).
b. Clean gas nozzle, Make certain that
gas diffuser is not restricted. Make
certain that gas cylinder is not empty
or turned off. Make certain gas sole-
noid valve is operating and gas flow
rate is proper. Remove gun liner and
check rubber seal for any sign of
deterioration or damage. Be sure set
screw in brass connector is in place
and tightened against the liner bush-
ing.
a. Do not exceed current and duty cycle
rating of gun. A light application of
high temperature antiseize lubricant
(such as Lincoln E2067 Graphite
Grease) may be applied to tip
threads.