small safety note
[snip]
> Should any grounded part of the board be connected to the
> > netural line on the AC?
>
> You should always ground the chassis of your equipment to earth
> ground. The neutral line will be connected to earth ground at the
> circuit breaker, so you don't need to connect it yourself; but many
> will to make sure that the path to earth ground is as short as
> possible.
>
> If you're going to float your neutral, you should make whoever does
> it jump through some hoops so you can avoid liability for
> electrocuting someone.
I think I must've misunderstood what you said. But after re-reading this
post a couple of times, what you said still sounds a bit dangerous. So let
me try to clarify a couple of points.
Whet talking about AC power, there are generally three lines - hot, neutral
and ground.
Hot is self-explanatory.
Neutral is, as the poster noted, connected to ground at the circuit breaker,
but that's THE ONLY PLACE where it should be connected. No "shortest path to
ground" argument applies here. This is probably the most basic rule that the
electricians who wired up your house had to follow if they had any hope of
the house passing the inspection. I am not sure what the poster meant by
"floating" the neutral, but if you "float" it, you won't have any current
flowing (unless you use the ground instead, which is a big no-no).
Ground exists for ∗safety∗ only. Under normal circumstances no current
should ever be present in that wire. If any current is present, something is
wrong. So, never connect it to anything but the case or the enclosure of
your project. (ok, that's a generalization, so there are exceptions, but it
is a pretty good and safe generalization to start with).
Vlad
--
Vlad's shop
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