Iirc gfci's are nec code allowed on non grounded lines because they will still trip, but you have to test with the gfci test button because they're only tripping on current difference, not like a breaker.
Yeah, IIRC the "proper" way to upgrade an ungrounded circuit to have a 3-prong outlet (without running new cabling) is to use a GFCI and label it "NO EQUIPMENT GROUND". This is considered safe, but is still ultimately a hack.
It assumes that any dangerous shocking current will be taking a path that isn't just coming back on its own white wire, presumably from taking an unspecified path to ground. This seems a reasonable assumption for safety (and the NFPA surely has looked at the data), but it doesn't really inform the above isolated-bathtub situation.
It assumes that any dangerous shocking current will be taking a path that isn't just coming back on its own white wire, presumably from taking an unspecified path to ground. This seems a reasonable assumption for safety (and the NFPA surely has looked at the data), but it doesn't really inform the above isolated-bathtub situation.