I agree, but doesn't that also apply to surge-suppression built into equipment? Should we stop requiring surge immunity testing on equipment? With best wishes DESIGN IT IN! OOO - Own Opinions Only <http://www.jmwa.demon.co.uk/> www.jmwa.demon.co.uk J M Woodgate and Associates Rayleigh England UK is a sovereignty, not a Zollverein-ty From: Richard Nute [mailto:[email protected]] Sent: Friday, September 15, 2017 10:56 PM To: [email protected] Subject: Re: [PSES] power strip details In my opinion, surge suppression in a power strip or in a product may protect the local environment from overvoltage, but may create additional overvoltages elsewhere on the system. Many surge suppression techniques place a momentary short-circuit on the mains. So, the local environment is near zero voltage for the duration of the overvoltage incident. But, the wires of the source constitute inductance. For the duration of the incident, the magnetic field surrounding the supply wires collapses, and the voltage at the other end of the inductance increases sharply. Voila! Other equipment, at a distance from the surge suppressor, is subject to overvoltage damage. Surge suppression is the domain of the electricity suppliers. And they are good at it! In the USA, the domestic service entrance will flash over at 6 kV. So, households should see no more than 6 kV overvoltages. Rich From: Kunde, Brian [mailto:[email protected]] Sent: Friday, September 15, 2017 9:15 AM To: [email protected] <mailto:[email protected]> Subject: Re: [PSES] power strip details John, I think surge suppression on power strips is more of a Marketing Gimmick than anything. We all know that in a real world surge event, the device that fires first will take the brunt of the hit, and may not survive a second hit. Power strips have become a throw-away item but maybe it is better than nothing. The built in surge suppression in your $3000 computer will easily protect your $5 power strip. But your computer may not survive more than one hit. The Other Brian From: John Woodgate [mailto:[email protected]] Sent: Friday, September 15, 2017 9:10 AM To: Kunde, Brian; [email protected] <mailto:[email protected]> Subject: RE: [PSES] power strip details Is this surge suppression a) effective, b) necessary? I have seen comments that suggest 'No' for both a) and b). With best wishes DESIGN IT IN! OOO - Own Opinions Only www.jmwa.demon.co.uk <http://www.jmwa.demon.co.uk/> J M Woodgate and Associates Rayleigh England - ---------------------------------------------------------------- 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] <mailto:[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) <http://www.ieee-pses.org/list.html> List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <[email protected] <mailto:[email protected]> > Mike Cantwell <[email protected] <mailto:[email protected]> > For policy questions, send mail to: Jim Bacher <[email protected] <mailto:[email protected]> > David Heald <[email protected] <mailto:[email protected]> >
- ---------------------------------------------------------------- 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]>
