Maintenance; Routine Maintenance; Periodic Maintenance - Lincoln Electric GMA WIRE FEEDERS LN-7 Operator's Manual

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ROUTINE MAINTENANCE

DRIVE ROLLS AND GUIDE TUBES
After feeding every coil of wire, inspect the drive roll
section. Clean the assembly as necessary. Do not
use solvent to clean the drive roll assembly as it may
wash the lubricant out of the bearings. The drive rolls
and guide tubes are stamped with the wire sizes they
will feed. If a wire size other than that stamped on the
rolls is to be used, the rolls and guide tubes must be
changed.
The drive rolls for 0.045 and 0.052 cored electrode
and 1/16, 0.068, 5/64, 3/32, and 7/64 electrode have
a double set of teeth so they can be reversed for
additional life. Between the two knurled rolls (except
1/16 and smaller rolls) is a shim washer which limits
the damage to the electrode if wire feeding problems
occur. Drive rolls for 0.023 through 0.052 solid
electrodes have no teeth.
Refer to the instructions included with the drive roll kit
for installation and replacement of the drive rolls on
the wire feeder.
WIRE REEL MOUNTING
To prolong the life of the reel shaft on the 50 to 60 lb
coils, periodically coat it with a thin layer of grease.
No maintenance to the two position brake is required.
If the brake shoe wears through to metal, replace the
brake assembly.
No routine maintenance is required for Readi-Reels
and 10 to 30 lb spools. Do not lubricate the 2 in.
spindles.
CONTACTOR CIRCUIT FUSE
The 2 amp, 250 volt fuse (F1) on the control P.C.
Board protects the contactor circuit (leads #4 and #2)
from overloads or shorts which can be caused by a
wrong connection at the power source.

PERIODIC MAINTENANCE

WIRE DRIVE MOTOR AND GEARBOX
Every year inspect the gearbox and coat the gear
teeth with a moly-disulfide filled grease. Do not use
graphite grease.
Every six months check the motor brushes. Replace
them if they are less than 1/4 in. long.

MAINTENANCE

GUN AND CABLE MAINTENANCE
For instructions on periodic maintenance for the
welding gun and cables, refer to the manual for your
specific model of welding gun.
Gun Nozzles (All)
1. Replace worn contact tips as required.
2. On Innershield guns, remove spatter from tip or
extension guide after each ten minutes of arc time
or as required.
3. Replace worn spring liners in nozzles. The life of
the liner can be doubled by rotating liner 180°. The
liner can be pulled out the back end of the nozzle
by wedging the blade of a small screwdriver in the
I.D. and pulling.
4. Inner parts of nozzles can be removed and
replaced by removing the internal hollow-lock set
screw from the contact tip end of the nozzle with a
5/32 or 3/32 Allen wrench.
The insert and retainer will normally fall out the end of
the nozzle but if they do not, gently drive the spring
liner towards the outgoing end of the nozzle.
When re-assembling nozzle, make certain the ceramic
nozzle insert (if used) is placed next to the spring
liner. The hollow-lock set screw is to be tightened to
give the dimension specified below as measured from
the end of the nozzle to the hollow-lock set screw.
GUN
K112 (500)
K113
K114
K115
K116
K126
K206
K289-5/64
K289-3/32 & .120
K309
LN-7 & LN-7 GMA
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DIMENSION
.38 IN.
.38 IN
.38 IN
.75 IN
.75 IN
.38 IN
.38 IN
.44 IN
.75 IN
.38 IN