Re: [PSES] Transformer insulation class

[Doug Powell]

Ian, My personal experience is mainly with custom switch mode transformers, some very high power and intended for use in high temperature ambients.  These have been used in European, North American and Asian markets. In every case these transformers have been approved through evaluation within the product or products where they are used. This evaluation included material classes for insulation, thermal and flammability; ‎construction review and finally performance testing within the product itself. In twenty years, I have yet to certify a custom made switch mode transformer as a separate component.   That said, I have on a couple of occasions had to get a special evaluation done on some insulating materials, such as ball pressure, hot wire, etc. In these cases, I find it best to have your supplier do these evaluations and pass the certs along to you. It can take months to complete. All the best,   Doug -------------- Sent from my smartphone, please excuse the typos. From: McBurney, Ian Sent: Thursday, May 19, 2016 3:19 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Reply To: McBurney, Ian Subject: [PSES] Transformer insulation class Hello colleagues.   The switch mode transformers we use in our power supplies are specified by the testing  agency as insulation class A even though the materials used in the transformer are all rated for 130°C operation. We have asked the agency to up rate the transformer to insulation class B but the say they cannot do this as the transformer would have to be approved as a component. Is this correct?   Many thanks in advance.   Ian McBurney Design & Compliance Engineer.   Allen & Heath Ltd. Kernick Industrial Estate, Penryn, Cornwall. TR10 9LU. UK T: 01326 372070 E: ian.mcbur...@allen-heath.com     Allen & Heath Ltd is a registered business in England and Wales, Company number: 4163451. Any views expressed in this email are those of the individual and not necessarily those of the company. - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher <j.bac...@ieee.org> David Heald <dhe...@gmail.com> - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher <j.bac...@ieee.org> David Heald <dhe...@gmail.com>