http://disqus.com/by/salimkumar/enMon, 21 Sep 2009 03:31:31 -0000http://ecmweb.com/mag/electric_witness_test_transformerpart/#comment-17027657<p>Dear Hameed,<br>Pls be specific about your requirement.<br>You want to know how to measure tan delta of a transformer or bushing or transformer oil? Or just wants to know what is tan delta and its significance?</p>salimkumarMon, 21 Sep 2009 03:31:31 -0000http://ecmweb.com/mag/electric_witness_test_transformerpart/#comment-17027595<p>Dear Raj,<br>In order to identify the fault, the oscillograms need to be analyzed. <br>Moreover, the manufacturer should have done the partial discharge, core loss test etc to confirm the failure.<br>The IEC standard for dielectric tests (IEC60076- 3) gives the details. Its annexure gives an idea about interpretting waveforms after a failre. Though it is not conclusive, it may help to some extend. From the time of chopping in the oscillogram, it is possible to estimate the distance of failure from the applied terminal of the transformer.<br>In my opinion, this case needs a detailed investigation.<br>Regards</p><p>Salim kumar</p>salimkumarMon, 21 Sep 2009 03:27:03 -0000