[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Ground fault circuit interrupter (GFCI or GFI)

>From: wshimoda at alum_mit.edu
>Subject: Ground fault circuit interrupter (GFCI or GFI) (was Re:T8 
>electronic ballast wiring)
>I spoke with an electrical engineer about this and he mentioned that the 
>GFCI alone may not protect you from electrocution.
>Imagine a simple situation with just an aquarium filled with water and a 
>heater with a broken glass tube.  The broken heater would cause a 
>hazardous condition in the water.  However, since the glass of the 
>aquarium makes an excellent insulator, the GFCI may not detect a 
>difference between the current flowing in each conductor and therefore 
>wouldn't trip.  But if you then stuck your hand in the water, some of the 
>current would now have a path by which it could flow to ground.  The GFCI 
>would then trip after detecting the resulting difference in current flow 
>between the two conductors.

Exactly, but the GFCI acts so quickly that the amount of time your body 
conducts the current is very very short.  Most likely you wouldn't even 
feel anything (maybe just a tingle?).

Hoa (another electrical engineer who has gotten shocked plenty o' times).

Hoa G. Nguyen
Freshwater Planted Aquarium: http://www.geocities.com/Heartland/Hills/2637/