Brian Thanks That generally confirms my own opinion in the past. I also have the same opinion regarding the general state of the standard wrt LVD compliance! Regards John Allen
From: Brian O'Connell [mailto:boconn...@t-yuden.com] Sent: 30 November 2004 15:40 To: John Allen; - EMC PSTC Posts (E-mail) Subject: RE: IEC/EN 61010-1, 2001 'Circuits derived from Mains Circuits' Mr. Allen, My "personal rule" is either the apparatus is ultimately connected to mains, or it is not; and various NCBs has supported that analysis. For an apparatus connected to mains, refer to Annex D to determine insulation requirements. Also, see 3.5.5, 3.5.6, and 4.3.2.4. Section 6.9 also indicates insulation types, according to the shock hazard. For apparatus not connected to mains, you can determine the over-voltage that it may be subject to, and may decide to use the formula in 6.7.3.2 . As you know, 6.7.3.2 and Table 9 have errors. IMO, IEC 61010-1 as a test standard for end-use apparatus, is more confusing than most LVD standards. I suspect that many answers can only be found in the standards listed in Annex ZA. luck, Brian -----Original Message----- From: John Allen [ mailto:john.al...@era.co.uk] Sent: Tuesday, November 30, 2004 5:27 AM To: - EMC PSTC Posts (E-mail) Subject: IEC/EN 61010-1, 2001 'Circuits derived from Mains Circuits' Hi Folks Sub-Clause 6.7.3.1 "Clearance values - General" and Table 5 of Clause 6.7.3. "Circuits other than MAINS CIRCUITS" refers to the term 'Circuits derived from MAINS CIRCUITS'. However, nowhere in the standard are there clear definitions or ranges of examples of what these circuits are, or of what they are not! Neither are there any references to other standards to provide this distinction. Therefore one cannot point clearly to a methodology for deciding what is, or is not, a 'Circuit derived from Mains Circuits' - except possibly that a totally battery powered unit with no charging facilities probably is NOT a 'Circuit derived from Mains Circuits' ! This leads me to the following questions: a) Where, if anywhere, is the dividing line between the two? b) If there is a dividing line, then how many layers of definable compliant insulation, isolation, barriering, transient reduction measures, etc., do you need to need between one and the other? c) If there is not a dividing line, then how the H*ll do you make the distinction and so be able to apply the standard? Thus, if anyone can shed some light on the unspoken meanings of this part of the standard, I would be most grateful! Thanks in advance. John Allen, _____________________________________________________________________ This e-mail has been scanned for viruses by MCI's Internet Managed Scanning Services - powered by MessageLabs. For further information visit http://www.mci.com ********************************************************************** Copyright ERA Technology Ltd. 2004. (www.era.co.uk). All rights reserved. The information supplied in this Commercial Communication should be treated in confidence. No liability whatsoever is accepted for any loss or damage suffered as a result of accessing this message or any attachments. ********************************************************************** _____________________________________________________________________ This e-mail has been scanned for viruses by MCI's Internet Managed Scanning Services - powered by MessageLabs. For further information visit http://www.mci.com ---------------------------------------------------------------- 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/listserv/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Scott Douglas emcp...@ptcnh.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
