Peter, Per IEC 60364 and BS 7671, you select wire and circuit breakers in accordance with Chapter 43 (IEC 60364-4-43), "Protection Against Overcurrent", and Chapter 52 (IEC 60364-5-52), "Selection and Erection of Wiring Systems." I have used these references enough to notice no reference to sizing branch circuits to "the noncontinuous load plus 125 percent of the continuous load."
Moreover, back when times were good, I was able to get approval to take the IEE Design Course for BS 7671, Requirements for Electrical Installation in London. I still have the course material, and looking through the sections on wire systems, fuses, and circuit breakers, there is no analogy to sizing the overcurrent protection to 125% of the continuous load like there is in the US and Canadian electrical codes. The analysis of the circuit breaker and fuses and situations are quite a bit different at times from analysis in North America. In general, you look at the time/current curves of the types of circuit breakers and fuses more closely, and do more math. Also, in Europe, you can use breakers and fuses as a means of protection against shock with 411 - Protective Measure: Automatic Disconnection of Supply. Here, you have a measurement of the earth fault loop impedance (Zs) co-ordinated with time/current characteristics of fuses and breakers, with the fuse/breaker opening quickly enough to protect against shock. This is generally not possible in North America. Best regards, DON GIES ALCATEL-LUCENT SENIOR PRODUCT COMPLIANCE ENGINEER BELL LABS - GLOBAL PRODUCT COMPLIANCE LABORATORY 600-700 Mountain Avenue Room 5B-104 Murray Hill, NJ 07974-0636 USA Phone: +1 908 582 5978 Fax: +1 908 582 0582 <mailto:don.g...@alcatel-lucent.com> don.g...@alcatel-lucent.com MEMBER, ALCATEL-LUCENT TECHNICAL ACADEMY -----Original Message----- From: Peter Tarver [mailto:ptar...@enphaseenergy.com] Sent: Thursday, May 03, 2012 5:12 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: Circuit breakers in Europe > From: Brian Oconnell <mailto:[mailto:oconne...@tamuracorp.com]> [mailto:oconne...@tamuracorp.com] > Sent: Thursday, May 03, 2012 08:36 > > Not certain what OP is attempting, as wire gage is dependent on the > fault calc found in electric code, and breaker rating is related to > the distribution. In North America, barring circumstances requiring deeper engineering calculations and supervision, a circuit sized for and protected by a 20 A breaker cannot carry long continuous currents larger than 16 A. My preexisting notion (for lack of better understanding) for Europe has been that a 16 A breaker is used to protect a 16 A circuit. (The "80% Rule" or a similar rule does not apply in Europe and overcurrent protection is generally matched to the circuit size.) I'm looking for either confirmation of or contradiction of that notion. So far, one vote received confirming. Regards, Peter L. Tarver This email message is for the sole use of the intended recipient(s) and may contain confidential and/or privileged information. If you are not an intended recipient, you may not review, use, copy, disclose or distribute this message. If you received this message in error, please contact the sender by reply email and destroy all copies of the original message. - ---------------------------------------------------------------- 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:emc-p...@ieee.org> emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: <http://www.ieee-pses.org/emc-pstc.html> 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/> http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: <http://www.ieee-pses.org/> http://www.ieee-pses.org/ Instructions: <http://listserv.ieee.org/request/user-guide.html> http://listserv.ieee.org/request/user-guide.html List rules: <http://www.ieee-pses.org/listrules.html> http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas < <mailto:emcp...@radiusnorth.net> emcp...@radiusnorth.net> Mike Cantwell < <mailto:mcantw...@ieee.org> mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: < <mailto:j.bac...@ieee.org> j.bac...@ieee.org> David Heald: < <mailto:dhe...@gmail.com> 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://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 <emcp...@radiusnorth.net> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com>
