Re: Death Row HV Question

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Eric Davidson by way of Terry Fritz <twftesla-at-qwest-dot-net>" <edavidson-at-icva.gov>

Richard et al,

There is alot of misinformation about the actual voltages used in the
electric chair.  Part of this is due to the fact that there is not alot of
standardization in the electric chair industry or among prison systems.
Secondly, most of what the public knows about the electric chair comes from
reporters accounts of executions and other information handed down from
various witnesses.  This is the stuff of urban myth.  The voltages used are
usually around 2400 volts.  This is probably because the primary voltage of
the electric utility was 2400/4160 volts in the early days (the hay day, if
you will) of the electric chair.  In any case, 2400 volts is not simply
applied between the calf and the top of the head.  This would force the
entire 2400 volts to be dropped across the body, and Ohm's law would
determine the current.  The results of this could be explosively destructive
and very unpredictable, a spectre unsuitable for viewing even by the most
experienced person.  I'm sure most of us have HEARD what happens when an
unsuspecting squirrel or the like gets across power lines.  Yes, a squirrel
is much smaller than a human, but the squirrel usually explodes, and little
or no remains can be found at the scene of the fault.  Instead, the current
applied to the individual is carefully regulated by a series of reactors.  I
don't know the exact current value, but my guess would be not much more than
1 ampere.  I've heard people say things like 6-8 amperes at 2400 volts! That
is 14-19 kW! Also, the current is not set to a specific value as to effect
fibrillation, because cessation of heart pumping is only part of the
execution process.  As gruesome as it sounds, there must be some heating of
the core of the body, as this causes destruction of vital organs and halts
the actions of life sustaining enzymatic reactions.
    As far as coming in contact with the high side of a 'pole pig' is
concerned, the result could most certainly be lethal, especially if the
circuit powering the pig was stout enough to maintain full voltage on the
low side during the fault.  Most high voltage encounters are, at the very
least, extremely destructive, especially at voltages under 69kV or so.  The
current flows deep into the tissue and bone, resulting in complete necrosis.
If you got across phase to phase, or phase to ground with your arms, and
were 'lucky' enough to survive, you would likely lose both arms, at least to
the elbow.  There would be devastating burns at the entry sites.  My guess
would be that ANY pole pig contact to the head would be lethal.  At higher
voltages, the current would more likely arc across the surface of your body
causing horrible burns, but less deep tissue damage.  Also, the shock wave
(kinda like thunder, I guess) would likely blast you clear of the contact.
But when you are at ground zero of a huge arc, which could easily dissipate
a megawatt or more (I'm talking about utility lines here, not at your
house), the potential for massive burning is inevitable.  I always say be
very careful around 'pole pigs', consider ANY contact with them to be
lethal.  NEVER think of them in the same light as their current limited and
much less lethal cousin, the neon sign transformer. Hope this helps.  As
always.....coil safe.

Eric
edavidson-at-icva.gov