This is what I was thinking of, from 60950-2000. 1.2.8.8 HAZARDOUS ENERGY LEVEL: A stored energy level of 20 J or more, or an available continuous power level of 240 VA or more, at a potential of 2 V or more.
John Woodgate <j...@jmwa.demon.co.uk> wrote: In message <497805.15292...@web39612.mail.mud.yahoo.com>, dated Sun, 12 Aug 2007, Bill Owsley writes: >Is there also a hazardous energy limit? something like 240 VA? > No, there is no fixed value. The body is sensitive to current, and different parts are differently sensitive. Nerves are most sensitive, and the action of the heart, itself controlled by currents, is probably most sensitive. A few milliamps can disrupt it. But those few milliamps might result from a much larger current flowing from hand to hand, or very few more milliamps flowing through nerves or blood from a faulty invasive medical device. The hand-to-hand path (with dry skin) has a resistance typically of 10 kohms, so, for example, a total current of 20 mA would require 200 V and an energy of 40 joules for every second that the current flowed. But the path through nerve and/or blood has a resistance of just a few ohms, so a lethal 5 mA into the heart would require maybe 25 mV and an energy of 125 microjoules for every second of current flow. -- OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk There are benefits from being irrational - just ask the square root of 2. John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - 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 _____ Fussy? Opinionated? Impossible to please? Perfect. Join Yahoo!'s user panel <http://us.rd.yahoo.com/evt=48516/*http //surveylink.yahoo.com/gmrs/yahoo_panel_invite.asp?a=7> and lay it on us. - ---------------------------------------------------------------- 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 email has been scanned by the MessageLabs Email Security System. For more information please visit http://www.messagelabs.com/email ______________________________________________________________________
