See static and active scr, Static and active scr tests, Troubleshooting & repair – Lincoln Electric SQUARE WAVE TIG 255 SVM100-A User Manual
Page 67: Static scr test, Warning caution
SQUARE WAVE TIG 255
F-26
TROUBLESHOOTING & REPAIR
STATIC SCR TEST
TEST DESCRIPTION
The Static SCR Test is a quick check to determine if an SCR is shorted or “leaky”. See
machine waveform section or normal and abnormal SCR waveforms.
MATERIALS NEEDED
Analog ohmmeter (Multimeter)
TIG 255 Wiring Diagrams (see Electrical Diagrams section of this manual)
SCR Heat Sink Assembly Drawing, Figure F.12
WARNING
CAUTION
Service and repair should only be performed by Lincoln Electric factory trained person-
nel. Unauthorized repairs performed on this equipment may result in danger to the
technician or machine operator and will invalidate your factory warranty. For your safe-
ty and to avoid electrical shock please observe all safety notes and precautions
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 the Lincoln Electric service department for technical
troubleshooting assistance before you proceed call 216-383-2531 or 1-800-833-9353
(WELD).
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If machine case sides and top are removed the case back and front must be support-
ed. Failure to do this could result in mechanical or electrical damage to the TIG 255.
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