tropical36 wrote:
You must remember that GFI's are able to detect very small amounts of current flow and no where near the pain threshold, so I would suggest that any appreciable amount of current flow to ground, would trip the breaker itself, by qualifying as a short circuit. I fully understand their worth, especially with using portable equipment in bathrooms, kitchens and outside receptacles, even though a nuisance for the most part. For other things, they're usually just a PITA, period. Now if all modern outlets and equipment didn't contain the third pin safety ground for metal cases, then it would be an entirely different story.
I suppose that depends upon what you mean by any appreciable amount of current. Leaking a few amps to ground is plenty to be dangerous, both in terms of personal and fire safety, but entirely insufficient to trip a 15A breaker.
A couple years ago I disconnected and removed a couple of old electric heaters from the basement of my house as they were no longer useful (I had no need of heating the basement) and looked to me to be of questionable condition. The circuit, until I shut it off to remove them, had been live with no apparent troubles for many years.
Upon dismantling one, I discovered that an internal wire had broken and shorted against the metal case of the heater, burning a hole in the back of the case and scorching the cinder block behind it a little. It apparently never drew sufficient current to trip the 20A breaker. (This was a 240V circuit, but that doesn't really enter into things at all; the potential between either leg and ground is 120V.) Needless to say, I was very, very glad it was mounted on the block wall and not in a wooden framed partition, where it could very easily have started a house fire.
A GFCI would have tripped in this situation. I assume an AFCI also would have tripped, at least if they do indeed work as advertised. Neither were required in this particular application when the house was built, and indeed I suspect that's still the case for a hardwired heating circuit.
