Thor Forums

[Chance]

Originally Posted by JamieGeek

Good question: Nope, same GFI in the house for years and I haven't touched it LOL.

Keep in mind what GFI does: The GFI trips when there is a short from one of the "hot" legs to ground (e.g. drop the toaster in water). Reversing the polarity (e.g. swapping the two "hot" wires) would not trip the GFI at all.

As I understand it, GFI compares current in hot leg to neutral, and if it's not identical (within 5 milliamperes or so) will trip. It does not have to go to ground.

Basically it protects us from shock by making sure we don't become a path from the hot leg to ground. If we do, then the current returning through neutral wouldn't match the hot, which is why it trips. It's a clever way to protect us indirectly.