>To all those electricians out there I need some enlightenment. I was feeding the
>gang this morning and inadvertently dropped my eye-dropper (feeding baby brine)
>into one of the tanks. I reached in to retreive and to my unpleasant surprise I
>received a SHOCK!! After recovering my composure, it was a small shock
>obviously, I reached in with my other hand (I guess one shock wasn't enough!),
>and - NOTHING! I noticed that one hand had a cut and the other did not. The hand
>with the cut registered the shock while the cut free hand did not.
>
>What's going on here and what should I do? All my electrical components are on
>GFI's. I was under the impression that they would detect current leaks and trip
>the breaker.
Yes and they will, but the current must first reach the trip point. A
GFI measures the difference of the current flowing out a returning
through the GFI. When the imbalance is to great they trip. If your
test functions works then you're safe.
>Is this current that I feel only on the hand with the cut dangerous? And why
>does the GFI not trip out?
Nope just doesn't feel good. Again you didn't pull enough current to
trip the GFI.
>Why exactly do I only get shocked on the cut hand?
Skin has a fairly high resistance (resistances reduces current flow)
and is a poor conductor of electricity. Flesh contains water and salt
which are both fairly good conductors. In other words your skin
protects the flesh underneath from conducting much electricity. The
skin is broken the electricity flows through an easier and more
concentrated path. I'll venture the guess you where also not wearing
shoes and standing on a concrete floor (or else touching metal that
was grounded). This provides the other end of the path for the
electricity.
>Is this current leak harming the fish in any way? In turning on and off the
>power supply I don't see the fish reacting in any noticeable way.
>I'm guessing one of the heaters is defective but, I have not yet isolated which
>one. This whole thing makes me somewhat nervous so, I'd appreciate a quick
>reply!
There has been some question as to if it can create some long term
effects. But is it going to kill them fast? No it will not. They are
not grounded and not in the path of electrical flow. In other words
they're not getting tickled like you are.
Next time you have a cut wear dry insulating shoes. In fact this is a
good idea whenever you work on your tanks. For electricity to pass
through you it must have a path to an opposite potential such as earth
ground. No doubt you floor is slightly damp and you feet slightly
sweaty (that is salt on wet skin creating lower resistance). When you
use the uncut hand this electricity leak is reduced (higher total
resistance) and spread over your body rather than traveling through
body and centering on the cut. That's the tickle you felt.
Later
Cary Hostrawser
Minnesota Aquarium Society
http://www.mn-aquarium.org/
Rainbowfish Study Group of North America
http://home.earthlink.net/~sbuckel/index.html