24 Jun
2005
24 Jun
'05
2:14 p.m.
In Norway, you will not get mains-powered devices
approved unless the
chassis is isolated. Our AC wiring does not have any concept of
"neutral", since both wires are supposed to be at the same potential
relative to ground. That way, everybody learns to be careful.
In the UK, althoguh one side of the mains is close to earth potential,
you are not allowed to assume this. Anything connected to the mains
(either side) has to be 'inaccessible without the use of a tool', and I
think devices have to remain safe if the live and neutral wires are swapped.
The 2 sides of the mains (live and neutral) are mentioned in the
regulations, in that signle-pole protective devices (like fuses) have to
be in the live wire, single pole switches must open the live wire (and
not the netural), Edison Screw lampholders must be wired so that the
outer shell is connected to neutral, and so on.
I have never come across a correctly functioning computer device that
puts high voltages on (say) the serial port if you swap live and neutral,
and I am sure such a device would not be acceptable over here.
-tony