worst night of my life

[midgetwaiter]

Originally Posted by Dale

A GFCI prevents an electrical component from drawing too much power from the grid (malfunctioning heaters, knocked in lights).

This is technically incorrect. What A GFCI does is detect that there is current leaving on the hot wire that is not being returned on the neutral. ie it is going to ground through you, this is when it trips. In Steve's situation the current didn't have a path to ground, the GFCI may not have stopped anything

A ground probe could also save you in the "knock the lights in" situation. If there is a device leaking current into the water the ground probe gives it a path to ground. The "save you" function of a ground probe is pretty simple, that current wants to go to ground and hopefully the probe provides a better way to do that than you do.

Talking about a ground probe "removing" stray voltage is also flawed. The assumption is that having this stray current in the tank is bad for the inhabitants but there isn't a lot of proof for it. A leaky device is giving you potential current but it's not until you get a path to ground, ie your probe, that you have current flowing through the water. Think about a bird on a power line. Touching one line, no problem but touch another line or the ground at the same time and you have a big problem. Is potential current or a completed circuit worse for fish and inverts? I don't think there is a definitive answer.

The thing that could have saved Steve's critters is both a GFCI and a ground probe. When the heater broke the current would have gone to ground rather than returning on the neutral and it should trip. This probably would have worked but I think you'd have to look far and wide to find many people that use both these devices.