Re: NANFA-- GFCI/FIRES/Electrical

Ty Hall (
Wed, 10 Dec 2003 18:04:40 -0600

Another great reason to install a grounding probe.

geoff wrote:

> Just recently, I rewired my garage to add a dedicated circuit for my fish
> tanks. Since the circuit is for fish, I installed a GFCI (correctly I might
> add). Besides - all circuits in garages have to be GFCI to meet code.
> A couple of months ago, I reached into one of my tanks and grabbed an old
> powerhead and got a BIG shock. It seems that over the years, the cord had
> pulled out of the epoxy enough for the bare wires to be exposed.
> However, the GFCI did not trip. I'm not saying 'don't have one', I'm
> saying - don't ignore routine inspection of your equipment just because you
> have a gfci. Also, don't expect a gfci to protect you 100%. They aren't
> magic. Since the powerhead did not have a ground, and the tank was not
> grounded, the GFCI did not trip.
> That's because GFCI's monitor the amount of current in the hot and neutral
> wires. If there is more than about 5 milliamp difference, the GFCI trips.
> The problem I ran into is that I got between the hot and neutral.
> Here's a link that explains how GFCI's work:
> Geoff Kimber
> Lexington,KY
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