Beating the electricity horse
Sorry to bring this issue back into circulation. Many of you, I'm sure,
were releived that the thread had died. But I have been behind on my APD
reading, so I just now read this comment from APD #383, and I couldn't sit
Steve Pushak wrote:
>The comment about 120v AC being non-lethal is in my opinion, (let me
>search for an appropriate adjective) SILLY! Where water is involved,
>no voltages can be considered safe when there is hazard of an
>electric potential being developed across your heart. This is also
>true for 10V devices operated by a transformer.
First, let me agree wholeheartedly, that, indeed, 120v AC can be quite
lethal. However, let me disagree that 10V DC will give you anything more
than a funny buzz.
Not that I want anyone to go out and put a 10V DC potential on their
aquarium and start fooling with it, but the hazards are, in fact, quite
The real danger comes from dealing with AC currents as opposed to DC
currents, and this is why noone should ever put a 120v AC line source into
their aquarium. You see, AC currents have the ability to de-fibrillate
your heart muscles, and cause cardiac arrest. It doesn't take much to do
it, either - as little as 10 milliamps AC current passing through your
heart spells big trouble.
Why this tirade? I just wanted everyone to be clear on the fact that the
real benefit of using a transformer for undergravel heating cables is NOT
that you reduce the voltage from 120 volts to 10 volts (or whatever). THE
REAL reason is that you convert a potentially fatal AC line voltage to a
much less harmful DC voltage.
Either way, don't forget your ground fault circuit interrupt if you have
anything electrical placed in your aquarium.
I'll hop down from the soap box now,
Steve in Ann Arbor where it's 5 degrees F, but the sun is shining.