Symptoms (analysis)
The specific symptom of the “DBDS corrosive sulfur – C1” problem is associated with the presence of:
DBDS – dibenzyl disulfide (IEC 62697-1).
If the concentration of DBDS exceeds recommended values (see table in the Diagnosis section) the necessary treatments must be implemented.
Possible analytical configurations for testing DBDS
- ECD – Electronic Capture Detector (IEC 62697-1 Ed.1-2012, par. 5.3.2);
- AED – Atomic Emission Detector (IEC 62697-1 Ed.1-2012, par. 5.3.3);
- MS – Mass Spectrometer (IEC 62697-1 Ed.1-2012, par. 5.3.4);
- MS/MS (IEC 62697-1 Ed.1-2012, par. 5.3.5);
- see also IEC 62697-1 Ed.1-2012, Annex B
There are other useful co-factors that complete the diagnostic picture:
TCS – Total Corrosive Sulfur (IEC 62697-2 draft)
Potentially corrosive sulfur – CCD (IEC 62535) test
Corrosive sulfur (IEC 62535, ASTM D1275 Method B, DIN 51353)
Oil fingerprint: GC-AED / GC-MS (IEC 62697-1) profile
Additives:Passivators (BTA, Irgamet 39, Irgament 30); oxidation inhibitors (DBPC, DBP)
Total sulfur (IP 373)
Particles (IEC 60970)
Evaluation of T1, T2 and T3 by analysis of dissolved gases (DGA – IEC 60599)
Total acidity TAN (IEC 62021-1 or IEC 62021-2)
By analysing the DBDS in oil
you can check for corrosion in the transformer
