GFCI Part #3

[alton]

Okay before we get started let us cover the standards for a GFCI receptacle which we hope will protect us.

GFCI Trip Level 4 to 6 mA (Industry Standard)

Which means it should trip at 4, but will definitely trip at 6

Okay I found this following information online.
1 mA you will feel a tingle
5 mA a shock felt and you should be able to let go?
10 to 20 mA you will have muscle contractions
100 to 300 mA will cause heart problems, spasms (hard to let go) and possible fatality
1000 mA will likely cause death
Amperage of 10 to 15 mA can be fatal if continued for more than a few seconds

1 mA = .001 amp and 1000 mA = 1 amp

Back to our GFCI receptacle tripping at 4 to 6 mA when there is an imbalance between the ungrounded and the grounded (neutral) conductors they will trip.
Problem: our aquariums are insulated because they are made out of glass or plastic which are great insulators. So you could have a bad heater, pump and the current is staying in your aquarium because the GFCI is balanced. This can cause a heater to become an even larger resistor until it explodes. Once you reach into the tank, you have now provided a grounding path so therefore the GFCI should trip in .025 seconds? Remember the chart for 1 to 5 mA and what it does to the human body and the fact is the GFCI will not trip for sure until 6 mA.
So therefore keeping a grounding probe in your tank provides a grounding path for the unbalanced load to travel if one of your pieces of equipment shorts out.
But remember your grounding has to be adequate at your service panel or your service will use your tank as a ground rod waiting for you to make the connection.

[jroescher]

Thanks for researching and posting this Alton. Maybe it will save someone, or at least explain why it's still not as safe as expected.

Here is an old thread that explains it a little more in depth:
http://www.maast.org/showthread.php?...arine-Aquarium