Lincoln Electric INVERTEC STT Series Service Manual page 49

F-8
TROUBLESHOOTING GUIDE
PROBLEMS
(SYMPTOMS)
Machine loses output while weld-
ing. The thermal indicator light is
lit. Normal welding output returns
after about 10 minutes.
If for any reason you do not understand the test procedures or are unable to perform the test/repairs safely, con-
tact the Lincoln Electric Service Department for electrical troubleshooting assistance before you proceed. Call 216-
383-2531 or 1-800-833-9353.
TROUBLESHOOTING & REPAIR
POSSIBLE AREAS OF
MISADJUSTMENT(S)
OUTPUT PROBLEMS
1. Check to make sure the fan is
running and operating correctly.
2. Welding application
exceed recommended
cycle.
3. Dirt and dust may have clogged
the cooling channels. Blow out
the unit with clean, dry com-
pressed air.
4. Air intake and exhaust louvers
may be blocked due to inade-
quate clearance around the
machine.
CAUTION
INVERTEC STT
Observe Safety Guidelines
detailed in the beginning of this manual.
RECOMMENDED
COURSE OF ACTION
1. The Darlington heat sink ther-
mostat or fan thermostat may
be defective. Check or replace.
may
duty
F-8