Rich, What are the legal effects on my employer for Ordinary vs. Skilled vs. Instructed Persons ? How does this affect the concept of an existing hazard as compared to a fault condition ? UL says that "A skilled person is expected to use their training and experience to recognize energy sources capable of causing pain or injury and to take action to protect them from injury from those energies".
Do you think that now is the time to get some HBSE training, or will we see a national implementation of IEC62368-1 before the apocalypse ? AFAIK, if a box allows contact that exceeds a certain voltage or current or power, there is a hazard, for all people. Am I being a primitive tribal idiot ? Can I assume that if UL/EN62368-1 gets published prior to the apocalypse, that the apocalypse as a procedural device can be certified for use by Skilled and certain Instructed Persons. Nothing I say or do indicates the policies of my employer; most certainly when I am very bad. Brian > -----Original Message----- > From: emc-p...@ieee.org [mailto:emc-p...@ieee.org]On Behalf > Of Richard > Nute > Sent: Friday, October 29, 2010 12:27 PM > To: jim.eich...@ca.schneider-electric.com > Cc: EMC-PSTC@LISTSERV.IEEE.ORG > Subject: Re: Protection system fault-tolerance hierarchy? > > > I don't want to re-invent the wheel, but I'm looking to > find a simple > > way to communicate the idea that some systems don't need > protection, > > others need protection, others need protection that will > still protect > > even with a single-fault present anywhere, and so-on. > Somewhere somebody > > must have codified this idea for example with type 0, > type 1, type 2, > > etc. I'm sure there are standards out there for this - > can anyone point > > me to one or more? > > > > Thanks, > > > > Jim > > > Hi Jim: > > The new IEC 62368-1 standard does exactly what you wish > for. > > The standard asserts that injury (or fire or whatever) > is due to a transfer of energy (from an energy source) > to a body (or other susceptible part). > > Energy sources are classed as: > > Class 1: Little or no perceptible effect on the > body (or other susceptible part) even in the event > of a single fault. No safeguards are required. > The energy source is inherently safe. > > Class 2: Sensation to pain on a body part but no > injury or equivalent on a susceptible part) even > in the event of a single fault. At least one > safeguard, e.g., a basic safeguard, must be > interposed between the energy source and a body > part (or other susceptible part). > > Class 3: Severe pain or injury to a body part or > equivalent susceptible part). At least two > safeguards, e.g., basic plus supplementary, or > a reinforced safeguard must be interposed between > the energy source and a body part (or other > susceptible part). The energy source is inherently > hazardous. > > The only difference between what we do today and this > new standard is the inclusion of the Class 2 energy > source criterion. Class 2 was included because most > telephone circuits fall between Class 1 and Class 3. > > The standard applies this concept to electric shock, > electrically-caused fire, thermal injury, mechanical > energy, radiated energy (acoustic, electromagnetic, > and optical), and chemically-caused injury. > > All of these energy sources have continuous > gradations from low (marginally detectable) to high > (injurious). Most energy sources have well-defined > and researched limits for "low" (non-hazardous). > > > Best regards, > Richard Nute > Product Safety Consultant > San Diego - ---------------------------------------------------------------- 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.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. 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>
