Troubleshooting - Lincoln Electric SAE-400 Operator's Manual

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PROBLEMS
(SYMPTOMS)
Machine fails to hold the "heat"
constantly.
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
FUNCTION PROBLEMS
1. Rough or dirty commutator.
2. Brushes may be worn down to
limit of life.
3. Brush springs may be broken.
4. Field circuit may have variable
resistance connections or inter-
mittent open circuit, due to loose
connections or broken wire.
5. Electrode or work lead connec-
tions may be poor.
6. Wrong grade of brushes may be
installed on generator.
7. Field rheostat may be making
poor contact and overheating.
8. "Current Control" may not be
operating properly.
9. "Current Control" brush holder
contact springs may be worn out
or missing. Contact surface may
be dirty, rough and pitted.
10. "Current Control" brush holder
support stud and mating contact
surfaces may be dirty or pitted
and burned.
11. Engine running at varying
speeds.
CAUSE
1. True and clean commutator.
2. Replace brushes.
3. Replace brush springs.
4. Check field current with ammeter
5. Tighten all connections.
6. Use only the recommended
7. Inspect and clean rheostat.
8. Check for loose or missing set
9. Inspect. Replace needed parts.
10. If brush holder internal contact
11. Set welder controls for maximum
CAUTION
SAE-400 ®
RECOMMENDED
COURSE OF ACTION
to discover varying current. This
applies to both the main genera-
tor and exciter.
Lincoln brushes.
screw in control handles.
Clean internal contact surface of
control device. Do not lubricate.
Smooth rough surfaces.
surface is pitted and burned,
replace the brush holder and
support stud. If the contact sur-
face is dirty, clean off the brush
holder stud and internal contact
surface. Apply mixture of three
parts silicone grease and one
part zinc powder (by weight) to
stud.
output and weld. Then, while
welding, check engine rpm. The
engine should be running at full
speed. If indicator shows a sig-
nificant difference, consult your
engine manual.
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