Originally Posted by
SeriouslyLost
The US system is designed to be safe with double insulation. Which is a great system, in theory. Except most times it isn't installed that way, thus rendering the entire circuit potentially unsafe. Contrast that with the UK/Oz/NZ Multiple Earth Neutral system that relies on a serial connection back to earth. The US system earths off any available earth potential, often copper plumbing mains or the external sheathing used to protect the wiring itself.
Plumbing mains do go into the ground and will conduct the charge away very well. I have never seen the external sheath used as the ground, it's merely connected to the ground. If you drive a nail through a metal-sheathed wire the breaker will trip but you're not going to be hurt even if you're standing in water. Drive it through a wire without a metal sheath, though...
Around here the metal sheaths are only used when a wire needs extra protection anyway.
That means that the potential for a reverse or cross phase situation that causes the entire plumbing system or conduits to become live can occur. Most civilized countries
use a separate earth line to a dedicated earth rod (you can't, in theory, cause the plumbing to become live) and don't allow protective sheathing/conduit to be metal or earthed off for any reason.
I don't think the plumbing could become hot enough to matter even if you shorted the mains to it and somehow didn't pop a breaker.
As for not grounding the sheath--see above.
The US system has phase always live: switched outlets are uncommon in most of the US.
Agreed.
US contractors tend to use single core copper or, even worse, aluminium wire. Such wire is harder to secure, more prone to breaking when being drawn at install and subsequent rewiring, and less capable of dealing with surges compared to the more common standard (in the EU and OZ/NZ/Jpn) multicore copper wire.
I don't think aluminum has been used for a long time. They thought it was a way to save money, experience showed it was a bad idea and we're back to copper.
US outlets consist of multiple parts, usually metal and seldom earthed. Contrast with the more common style in NZ & Oz where the outlet and external plate are one assembled piece and incapable of carrying current outside of the connectors themselves, usually attached to a single, non-conductive outlet box. Etc, Etc.
Or were you just being facetious?
I think having the plate separate is a good idea. That way you don't have to mess with the electric part of it if you want to pull the plates for painting. I also have a couple of outlets where I pulled the screw that holds the plate so I had the screwhole available for a splitter that turns things sideways. (For example, in the kitchen I put in such a splitter. While it has 6 outlets I'm still only using two, the advantage being that they now face sideways and thus the wire doesn't get a sharp bend if something is pushed back against it. I likewise have one on the plug under my desk to avoid having a wire sticking out.)