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electrical safety

>From: johnc at msc_edu (John Cavanaugh)
>Date: Fri, 8 Mar 1996 09:23:33 -0600 (CST)
>Subject: Re: Aquatic Plants Digest V1 #310
>
>KB Koh <KB_Koh at ccm_ipn.intel.com> writes:
>> It would take something like 1 Ampere to kill someone. ...
>
>When I was in Electrical Engineering school, I was told that 70
>milliamps was enough.

I had a look into another safety guide and it says 200mA. I had someone 
here arguing with me that current won't kill but voltage do. Good luck 
to him.

>From: nguyenh at nosc_mil (Hoa G. Nguyen)
>Date: Fri, 8 Mar 96 09:23:03 PST
>Subject: Re: Aquatic Plants Digest V1 #310
>
>Now here you get confusing again!  The ONLY reason the current is ever low
>when flowing through your body MUST be due to the drop in voltage!  Remember
>
>                       Current = Voltage / Resistance
>
>and your body resistance isn't changing!  To have a low body current
>requires you to go back to case (a).

I must admit that I was really getting confused with Kirchoff Law for a while, 
forgetting about the Ohms Law. Having spent 8 years in software is no excuse for
me :-( Since your *case (a)* is not applicable to utility supply at home, I 
would say that the reason low current flow is because body resistance to ground 
is very high. For 240V main and body resistance to ground of say 1MegaOhms, the 
current is 0.24mA enough to give you a good shock. If you are wet from playing 
with fish tank, the resistance to ground may go very low and that would be 
really dangerous and may be fatal. Now my Disclaimer: To get body resistance to 
ground of 1MOhms or higher would require you to wear good insulating footwear 
and dry skin.

>of a ground path!  And you'd better hope it's a very quick-acting fuse!  Or
>have a Ground-Fault-Interupt in the circuit (I do).

What is that Ground-Fault-Interrupt? Is it the same as ELCB (Earth Leakage 
Circuit Breaker). Over here it is required by law for every home to have it.

The better way is to ground the water with a wire and hook it to ELCB or 
your GFI(?). Any current leakage to the water would immediately trip the 
breaker. Anyone know of any side-effect to the water here?

>Okay, NOW let's get back to plants.

I'm talking about safety with fish tank now :-) Did someone just cried 
PLANTS!!!

rgds..kbkoh