I knew someone was going to ask this.. A few years back, I was attending a UL 1950 seminar in Minneapolis. One of the presenters (a fellow named 'Bahra') happened to mention that UL has a specification for the 'electric chair'.
The operating current was quoted by him to not exceed 70ma. I jotted down this figure, but unfortunately the voltage and clause was not mentioned, and I was hesitant to ask. The topic at the time was AC electric shock. In my copy of the slide presentation (slide 25), I noted the effects: (for AC electric shock, verbatim, with figures added as quoted) -perception .05 to .5ma -reaction 2 to 5ma -inability to let-go 5 to 20ma -ventricular fibrillation 20ma + -cell damage 20 to 70ma -burn hazard (high frequency) No voltages or frequency were specified.. btw, I lived in Portland, Or. in the 70's and had a friend that worked at the Tek Wilsonville plant. He had the most amazing set of tools...I think I kinda bonded with him. Now, I have even more tools than he did.. <Tim Allen porking in background> Kyle Ehler KCOIQE <mailto:kyle.eh...@lsil.com> Assistant Design Engineer LSI Logic Storage Systems Div. 3718 N. Rock Road U.S.A. Wichita, Kansas 67226 Ph. 316 636 8657 Fax 316 636 8321 -----Original Message----- From: Dan Kinney (A) [mailto:dan.kin...@heapg.com] Sent: Tuesday, November 13, 2001 3:56 PM To: Rich Nute; gkerv...@eu-link.com Cc: jrbar...@lexmark.com; emc-p...@majordomo.ieee.org Subject: RE: Define Continuous DC Voltage Does anyone know what voltage is used in electric chairs? Just Curious. Dan Kinney Horner APG Indianapolis > -----Original Message----- > From: Rich Nute [SMTP:ri...@sdd.hp.com] > Sent: Tuesday, November 13, 2001 2:08 PM > To: gkerv...@eu-link.com > Cc: jrbar...@lexmark.com; emc-p...@majordomo.ieee.org > Subject: Re: Define Continuous DC Voltage > > > > > > Hi Gregg: > > > > There was also a very good (but short) article by Tektronix in the > 70's > > called The Lethal Current. > > > > It concluded that currents between 100 mA and 3 Amps were more lethal > that > > currents of more than 3 Amps because those high currents tended to > 'restart' > > the heart. > > Hmm. Having been the manager of product safety at Tektronix in > the '70's, I don't recall such an article. At least not by that > name. > > Electric energy causes various injuries to the body depending > on the magnitude of the energy. Only two of the injuries can > lead to a fatality. > > The two injuries are fibrillation of the heart, and overheating > of internal organs, especially the liver. > > Fibrillation is caused by ac current in the range of 50 mA to > 500 mA (external connections) where the current pathway through > the body includes the chest (and the heart). Above 500 mA, > fibrillation is not a likely consequence. (And, I believe I > am correct in asserting that dc cannot cause fibrillation.) > > Overheating of internal organs is a function of power dissipated > in the body, where the body impedance can be taken as 1000 ohms. > The power required depends on the time of contact. Electric > utility linemen are subject to such injury. Consider 1 ampere > through 1000 ohms is 1000 watts! (The electric chair kills by > over-heating the internal organs, not by fibrillation.) > > So, Gregg's statement that there is both a lower and upper limit > for fibrillation is correct (although I do not agree with Gregg's > values). > > > Best regards, > Rich > >
