I would look at the various overvoltage protection circuits. When OVP operates, it may protect the immediate circuits from damage. But, when an OVP operates, the energy stored in the supply circuit inductances and capacitances has to be dissipated somewhere else. The energy can go anywhere on the supply network.
"An SPD puts a momentary very low impedance to earth on the distribution system. Such a tactic assumes transient overvoltages can be eliminated by connecting them to earth. The sudden change in current causes a change in the field of an inductor which causes a transient voltage across the inductor."* *Diverting Surges to Ground: Expectations versus Reality, François D. Martzloff, Proceedings, Open Forum on Surge Protection Application, NISTIR-4654, August 1991, National Institute of Standards and Technology, Gaithersburg, MD Joe Randolph presented a paper at the 2013 Symposium, and re-published this year in In Compliance magazine. His hypothesis is that OVP operation created the failures that he could not otherwise explain. He had data which supported his hypothesis. Best regards, Rich - ---------------------------------------------------------------- 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 <[email protected]> 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 <[email protected]> Mike Cantwell <[email protected]> For policy questions, send mail to: Jim Bacher: <[email protected]> David Heald: <[email protected]>
