Electronic – Aren’t non-polarized plugs a little dangerous? Why still use them


Sorry if there is an answer for this kind of question somewhere. I can't find it anywhere.

Take a look at obvious toaster example:
If you live in Europe and have non-polarized plug and a toaster (a bad one without double-pole turn off) – you have a 50% chance of touching the hot wire (via the heating elements or even bread if you're unlucky) if you plug it in the wrong way, so that the off switch turns off just the neutral wire. You will be shocked if you somehow connect your body to ground (through another device for example).

I understand that these conditions are not very likely to happen, but why do many countries still not even think about doing away with non-polarized sockets and adopt polarized?
I'm sure even in Europe the light-bulb sockets are wired to be neutral-shell polarized, so why not wall sockets?

Sure it is not a cheap thing to do, but 10 years later it will be even more expensive since more stuff will be produced without a polarized plug.

Best Answer

A couple of things.

A very small point, the UK is in Europe, and AFAICR we have had 3-pin plugs, 3-wire cables, since the late 50's.

My house was rewired in the 80's, and we have Earth Leakage Circuit Breakers (ELCB) on every circuit. So even if I stuck a fork into my toaster while grabbing a copper water pipe, I'd expect it to trip (I am not willing to back this up with evidence :-)

When I have visited continental Europe, I am pretty sure that I've seen the same ELCB technology in use.

I suggest that is even more effective than having an Earth connection; after all, if I touched the correct bit of wire in your toaster with my fork, without touching anything else, the Earth connection via a plug would do me no good. Further, unless the device had a metal case connected to Earth, I don't think I am much more likely to touch both Earth and live than just live alone.

I imagine the cost of rewiring all of the houses in Europe which have two-wire cabling t have three-wire would be very large. However, upgrading the distribution panel with ELCB is pretty simple (a drop in replacement in some cases for an old fashioned fused unit), and could be caused to happen more easily when electricity metres need replacing.