>From K.98: 3.1.4 multiservice surge protective device (MSPD) [ITU-T K.85]: A surge protective device (SPD) containing both telecommunications and mains protection. It may also include port protection for video or Ethernet
Cheers, Adam in Atlanta On Tue, Sep 19, 2017 at 4:16 AM, John Woodgate <[email protected]> wrote: > Good info. What is an MSPD? > > With best wishes DESIGN IT IN! OOO – Own Opinions Only > www.jmwa.demon.co.uk J M Woodgate and Associates Rayleigh England > > UK is a sovereignty, not a Zollverein-ty > > -----Original Message----- > From: mickm [mailto:[email protected]] > Sent: Tuesday, September 19, 2017 8:51 AM > To: [email protected] > Subject: [PSES] power strip details > > IEEE Std. C62.41.1 (2002 - reaffirmed 2008) contains a mountain of > information. If you go to A.2.2.3 Voltages induced in cables adjacent to > down-conductors, it covers the induced voltage in an open-circuit loop by a > nearby lightning current. The induced voltage table gives values ranging > from 50 V to 500 V. Do the same calculation for Ethernet cables and you end > up with voltages in the kV region. The inclusion of a voltage limiter is > not covered. The poor coupling between the source and victim means that the > voltage limiter current is surprisingly small. > > My previous comments are comprehended with statements like "The resulting > voltages induced in the loop by the fast-changing surge currents flowing in > the grounding system can cause a large voltage difference between the power > port and the telecommunications port". > Hence paving the way for the use of MSPDs to reduce the inter-service > voltage differences for equipment or equipment clusters. > > At the time of document creation, MSPDs where not widely used and in Annex > D called "surge reference equalisers". To understand how the MSPD transfers > the surge on one service to another you need to look at more modern > documents like ITU-T recommendation K.98 (08/2014) Overvoltage protection > guide for telecommunication equipment installed in customer premises. This > Recommendation covers direct strikes to the incoming service feed, mains > configuration types of TN-S, TN-C, TN-C-S, TT and IT together with effects > of various earthing system lead lengths and earth electrode resistances. > > Time is running out for IEEE Std. C62.41.1, under new IEEE rules the life > of a standard is 10 years. If nothing is done to revise C62.41.1 it with be > withdrawn in 2018. Hopefully the IEEE PES Surge Protective Device Committee > will take up this challenge and, as part of the revision rational, replace > the 10/350 with the more realistic values from CIGRÉ Technical Bulletin > (TB) 549 (2013) Lightning Parameters for Engineering Applications > > > Regards, > > Mick Maytum > > Safety and Telecom > Standards > > [email protected] > > https://ictsp-essays.info > > > ------ Original Message ------ > From: "Richard Nute" <[email protected]> > To: [email protected] > Sent: 18/09/2017 18:58:00 > Subject: Re: [PSES] power strip details > > >Hi Ralph: > > > >Thanks for the reference. My comments are validated by ANSI C62.41.1 . > > > >Best regards, > >Rich > > > > > >-----Original Message----- > >From: Ralph McDiarmid [mailto:[email protected]] > >Sent: Monday, September 18, 2017 9:01 AM > >To: [email protected] > >Subject: Re: [PSES] power strip details > > > >Pardon me, the correct reference is ANSI C62.41.1 (finger trouble on > >keyboard) > > > >Ralph McDiarmid > >Product Compliance > >Engineering > >Solar Business > >Schneider Electric > > > > > >-----Original Message----- > >From: Ralph McDiarmid > >Sent: Monday, September 18, 2017 8:55 AM > >To: [email protected] > >Subject: RE: [PSES] power strip details > > > >While I agree that an SPD at the service entrance seems to be the way > >to suppress surges resulting from direct/near/far lightning strokes, > >ANSI C62.4.1 writes about switching transients on circuits which cause > >oscillatory surges on the mains. SPD at service entrance might be less > >effective for those. The ANSI standard seems a very good summary of > >what is a complex topic. > > > >Ralph McDiarmid > >Product Compliance > >Engineering > >Solar Business > >Schneider Electric > > > > > >From: Richard Nute [mailto:[email protected]] > >Sent: Saturday, September 16, 2017 12:30 PM > >To: [email protected] > >Subject: Re: [PSES] power strip details > > > > > >I believe the principal culprit is the extreme magnetic field that > >surrounds the conductors when the surge protector operates rather than > >the current in the PE conductor. This field can generate high voltages > >in adjacent and nearby low-voltage conductors such as telephone and > >data cables. Think air-core transformer. > > > >If the surge protector is at the service entrance, then the high > >current is in the electricity supplier wires, and the coupling to > >telephone, cable, and data cables is reduced due to the distance > >between the wires. > > > >http://www.nemasurge.org/faqs/ > > > >Rich > > > > > >From: mickm [mailto:[email protected]] > >Sent: Saturday, September 16, 2017 1:40 AM > >To: mailto:[email protected] > >Subject: [PSES] power strip details > > > > > >John, > > It seems to me that TC 108 documents really devise surge protection > >component tests rather that complete equipment tests and so miss some > >hidden field gotchas. > > > >I with Richards point about surge protection, for me the concern is the > >surge current being diverted into the PE system creating local PE surge > >differential voltage rises. > >Multi-service surge protective devices (MSPDs) - all in one surge > >protection (mitigation actually) - can cause problems here by > >transferring a surge on one service, say AC mains, to another service > >e.g. telephone service, because that service feed offers a better path > >for the diverted surge current than the PE connection. > >Equipment connected to the protected output of the MSPD should survive > >the surge, but equipment connected on the unprotected side may suffer > >due to the unexpected diverted surge. Solution, put and MSPD on every > >bit of equipment. Looks like a win-win situation for MSPD > >manufacturers. > > > > > >Regards, > >Mick Maytum > >Safety and Telecom > >Standards > >mailto:[email protected] > >Ictsp-essays.info > > > >------ Original Message ------ > >From: "John Woodgate" <mailto:[email protected]> > >To: mailto:[email protected] > >Sent: 16/09/2017 08:04:59 > >Subject: Re: [PSES] power strip details > > > >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/ J M Woodgate and Associates Rayleigh > >England > > > >UK is a sovereignty, not a Zollverein-ty > > > > > >- > >---------------------------------------------------------------- > >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 <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 > >List rules: http://www.ieee-pses.org/listrules.html > >For help, send mail to the list administrators: > >Scott Douglas <mailto:[email protected]> Mike Cantwell > ><mailto:[email protected]> For policy questions, send mail to: > >Jim Bacher <mailto:[email protected]> > >David Heald <mailto:[email protected]> > > > >______________________________________________________________________ > >This email has been scanned by the Symantec Email Security.cloud > >service. > >______________________________________________________________________ > >- > >---------------------------------------------------------------- > >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 <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 > >List rules: http://www.ieee-pses.org/listrules.html > >For help, send mail to the list administrators: > >Scott Douglas <mailto:[email protected]> Mike Cantwell > ><mailto:[email protected]> For policy questions, send mail to: > >Jim Bacher <mailto:[email protected]> > >David Heald <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]> > > > >- > >---------------------------------------------------------------- > >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]> > > - > ---------------------------------------------------------------- > 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]> > > - > ---------------------------------------------------------------- > 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]> > - ---------------------------------------------------------------- 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]>
