John: Are "such words of explanation" allowed in an IEC standard, or do the standards have the same limitation applied to them as the IEV has?
Jim Eichner, P.Eng. Compliance Engineering Manager Xantrex Technology Inc. phone: (604) 422-2546 fax: (604) 420-1591 e-mail: jim.eich...@xantrex.com web: www.xantrex.com 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: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of John Woodgate Sent: Friday, February 03, 2006 11:35 AM To: emc-p...@ieee.org Subject: Re: Definition of Residual Current In message <de87437fe365cb458c265ea3d73b6f1d013da...@xbc-mail1.xantrex.com>, dated Fri, 3 Feb 2006, Jim Eichner <jim.eich...@xantrex.com> writes >I am working on a standard for which a definition of Residual Current >is needed. I don't own any other standard that defines it, and I don't >subscribe to the IEC electrotechnical vocabulary (perhaps I should). At >any rate, I could use some help please. > >1. Does anyone have an official definition for me? Please state your >source. There are several in the IEV, but see below. Some apply only to 3-phase supplies without a neutral conductor. > >2. According to the standard for RCCB's, IEC 61008-1, here's the >definition (translated from German to English by a colleague, so >perhaps not verbatim from the English version of the standard): > >Residual current: "Vector sum of the actual values of the currents >flowing in the main circuit of an RCCB" > >That seems like a pretty poor definition to me, as it is circular and a >bit vague It's close to the IEV definition 442-05-19: r.m.s. value of the vector sum of the currents flowing through the main circuit of the residual current device But yes, your 'translator' had better not give up the day job. (;-) >(I'm guessing "main circuit" should read "mains circuit" but still that >could be interpreted to include the earth wire in which case it's >incorrect). No, 'main circuit' excludes the earth wire. > >I think the definition does not need to and should not make any >reference to an RCCB, because residual current exists whether or not an >RCCB is used, and using RCCB in the definition just requires a >definition of RCCB, leading back to a need to define what Residual >Current is. > >I think the definition should be something like this: > >"Residual Current: The vector sum of the currents in each phase and >neutral (if applicable), OK so far, and similar to another, but less satisfactory, IEV definition, which says 'algebraic' instead of 'vector' and is thus not really correct. >which if non-zero indicates that current is returning to the source via >a path other than the current-carrying conductors, which therefore >indicates a potential shock hazard." Such words of explanation are not permitted in an IEV definition. > -- OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk 2006 is YMMVI- Your mileage may vary immoderately. John Woodgate - 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 emc-p...@ieee.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...@ptcnh.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: emc-p...@daveheald.com 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 emc-p...@ieee.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...@ptcnh.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: emc-p...@daveheald.com All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
