You're probably right in real life, John, but my (admittedly vague) recollection is that the SAE test waveform for the clamped version actually makes us deal with more enery. Maybe the standardized test waveform and real life are not in alignment. How unusual!
Jim Eichner, P.Eng. Compliance Engineering Manager Xantrex Technology Inc. e-mail: [email protected] web: www.xantrex.com Any opinions expressed are those of my invisible friend. Confidentiality Notice: This email message, including any attachments, is for the sole use of the intended recipient(s) and may contain confidential and privileged information. Any unauthorized review, use, disclosure or distribution is prohibited. If you are not the intended recipient, please contact the sender by reply e-mail and destroy all copies of the original message. From: [email protected] [mailto:[email protected]] On Behalf Of John Woodgate Sent: Thursday, April 27, 2006 2:08 PM To: [email protected] Subject: Re: Surge testing limits - research question In message <[email protected]>, dated Thu, 27 Apr 2006, Jim Eichner <[email protected]> writes >Great point. I don't think C62.41 takes that clamping into account. Well, it is probably wise not to, when you consider the impedances, conductor resistance AND inductance, between the power network and the clamping device. The network doesn't really 'see' the clamping device. >The SAE standard for surges on DC systems has waveforms for both >situations - unclamped and clamped (by other products in the system >that have their own TVSS). The clamped waveform turns out to be harder >to protect against in some ways - lower peak voltage, longer duration, OK so far. >more energy under the curve. H'mmm. If you clamp a transient, the 'pass through' energy must go down, I think, because some is dissipated in the clamping device. I think it's the longer duration that is the cause of trouble. -- OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk 2006 is YMMVI- Your mileage may vary immensely. John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to [email protected] Instructions: http://listserv.ieee.org/request/user-guide.html 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] All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to [email protected] Instructions: http://listserv.ieee.org/request/user-guide.html 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] All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
