On Sun, 21 Mar 2010 12:46:20 -0700 (PDT), harry
wrote:

On Mar 21, 4:49*pm, HerHusband wrote:
As in electrocuted to death in the absence of an underlying health
condition? Having myself received 120V a few times, I'd be interested
in that, too.
120V feels like the world's biggest, wriggliest worm crawling through
you at about 500 miles per hour. But I'm not dead. I think.

It's not the voltage that kills you, it's the current.

For example, a typical static shock can be thousands of volts, but the
current is so low it's usually nothing more than a quick "ouch" (though
it's still enough to destroy some sensitive electronic circuitry).

I've been shocked by 120V a few times in my life as well. *The reason I
lived to tell about it is because there was enough resistance through my
skin, clothing, shoes, carpeting, or whatever to keep the current low
(combined with the reflex jerk that pulled me away from the wire).

Think of a bird sitting on major power transmission line. There may be
thousands of volts in that wire, but the resistance to ground (i.e. the
air) is so high that it can sit there unharmed.

Common 120V household electricity can easily kill you if the resistance to
ground is low enough. i.e. dropping a hairdryer in your bathtub, or
changing a fuse while standing barefoot in a puddle of water.

Anthony

I seem to remember reading somewhere the lowest voltage causing a
fatality was 40V. But 10mA through the heart will stop it. We have
240V single phase/415V three phase in the UK and also in most of
Europe. However we also have Residual Current Circuit Breakers the
detect more than 30mA leakage to earth and cut off power in less than
1/2 cycle.

Yes, it's the current that kills (if enough of it passes through the
right path), but the voltage creates that current:

I (current) = V (voltage) / R (resistance)

The lower your skin/body resistance (wet skin has much lower
resistance than dry skin) or the higher the voltage, the higher the
current.

Lower voltages often aren't as dangerous for 2 reasons:

1) Whatever your body's resistance, the current is lower

2) The low voltage is often supplied by batteries or transformers
with lower current capacity (high internal resistance) -- if your body
tries to sink a lot of current (low body resistance), the voltage
drops significantly. On the other hand, a car battery can supply
hundreds of amps at 12V, and you could easily electrocute yourself
with one if your body resistance/path is right.

Josh