A very nice clarification; thanks Rich. As a case in point, I know of a least one high school in this jurisdiction where students (instructed persons) are allowed to assemble and test circuits consisting of magnitude 3 energy sources. I wonder if the school board needs to review that practice, since the principles of electric circuits can be taught just as effectively using magnitude 1 energy sources.
Ralph McDiarmid Product Compliance Engineering Solar Business Schneider Electric -----Original Message----- From: Richard Nute [mailto:ri...@ieee.org] Sent: Thursday, November 09, 2017 1:04 PM To: Ralph McDiarmid <ralph.mcdiar...@schneider-electric.com>; EMC-PSTC@LISTSERV.IEEE.ORG Subject: "persons" in IEC 62368-1 In IEC 62368-1, three different persons are defined with respect to their knowledge of safety, not with respect to other parameters. An "ordinary person" is naïve with regard to the safety of the equipment. Therefore, an "ordinary person" must have the full protections specified in the standard. "Ordinary person" is defined in the IEC Glossary, http://std.iec.ch/terms/terms.nsf/3385f156e728849bc1256e8c00278ad2/e6936aca232ebc83c1257cac004ac0a7?OpenDocument A "skilled person" is an expert with regard to the safety of the equipment. He is "expected to use their training and experience to recognize energy sources capable of causing pain or injury and to take action for protection from injury from those energies." None of the protections specified in the standard are applicable to a "skilled person." He can work on the equipment with the covers off. Ralph worked on TVs with the covers off and was able to avoid injury because of his knowledge of the energy sources, so, with respect to TV safety, he was a "skilled person." "Skilled person" is also defined in the IEC Glossary. An "instructed person" is just that. He must be instructed as to energy sources that could cause pain and the precautions he must use to avoid the pain. And, he cannot be exposed to energy sources that could cause injury. Instruction must be by someone who knows the energy sources in the specific equipment and knows the precautionary measures that must be taken to avoid pain, which means that the instruction must be by a "skilled person." "Instructed person" is defined in the IEC Glossary. Associated with the person definitions, IEC 62368-1 defines three magnitudes of energy. Magnitude 1 may be detectable, but not likely to cause pain or injury. An "ordinary person" may have exposure to magnitude 1 energy sources, e.g., low voltage. Magnitude 2 may cause pain, but not likely to cause injury. An "instructed person" may (is allowed to) have exposure to magnitude 2 energy sources. Magnitude 3 may cause injury. A "skilled person" may have exposure to magnitude 3 energy sources, e.g., mains voltages. Rich -----Original Message----- From: Ralph McDiarmid [mailto:ralph.mcdiar...@schneider-electric.com] Sent: Wednesday, November 1, 2017 2:38 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Regulatory requirements for MOVs placed line-to-ground on AC mains ports? IEC 63386-1 seems to introduce a lot of new terms I have not seen used in other IEC standards. ( but I haven't read everything out there) I would add that a "skilled person" perhaps is a "qualified person" , but qualification is often associated with formal training by an accredited institute, not just on-the-job experience. I have fixed a few TVs in my time, but I wouldn't say I was qualified; skilled maybe. Ralph McDiarmid Product Compliance Engineering Solar Business Schneider Electric ______________________________________________________________________ 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 <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://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 <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com>
