IEC 62271-307: Very useful but still little known. A door to avoid tests in high voltage switchgear.
image credit: Image prepared by Sergio Feitoza
- Mar 17, 2020 9:28 pm GMT
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The preparation of document IEC 62271-307 started in 2011. It was published in 2015. Its title is “High-voltage Switchgear and Controlgear -Part 307: Guidance for the extension of validity of type tests of AC metal and solid-enclosed switchgear and controlgear for rated voltages above 1 kV and up to and including 52 kV”. I am co-author and was a member of the IEC working group that prepared it. Many ideas related to the use of test simulations to replace real tests are contemplated .This IEC Report focuses on medium voltage panels (IEC 62271-200 and 62271-201). In the same way that IEC 61439 and the old IEC 60439 (low voltage switchgears) it brings good opportunities to avoid the unnecessary repetition of expensive tests.
These opportunities can be taken advantage of, by manufacturers who choose the correct “first of a family” equipment to test in the laboratory. At the end, It will be successful only if, they get a test report in hands that transparently describes the details of what was actually tested, in the light of the tables in IEC 62271-307.
Testing laboratories rarely report this in a detailed way, as needed bi IEC 62271-307. Some of them don't even write if the equipment has been approved or not. So, you need to talk to the lab about this, when booking - before - the test.
Just for reference, in the same approach, the old IEC 60439 (low voltage switchgear) permitted to replace the temperature rise and short circuit tests (the part about electrodynamic forces) with calculations comparing a tested project with another similar one not tested. The IEC 61439 standard was an evolution of it bringing the intelligent “Design Rules” that avoid many tests However it has a serious flaw in the temperature rise test where, in addition to being confusing, there is no table that allows a human to know what are the temperature rise limits allowed as explained in the article http://www.cognitor.com.br//TemperatureRise_IEC61439Mistery.pdf
For the ones interested in knowing more about IEC 62271-307 read the complete article in this link https://lnkd.in/dx_wJ7i