> I have never really understood the mania on this third wire or
> "Ground" wire
> in the US since 99.9% of all electrical panels have the
> supposedly "Neutral"
> wire and the "ground" wire connect to the same buss.
Well, consider what happens if you have an appliance with a metal housing,
connected to safety ground, and the neutral (power carrying) conductor has a
break in it. With a separate safety ground, the appliance just stops
working. But if the neutral is used for a safety ground, the housing will
be hot !
Of lesser importance (but still a consideration) is the voltage drop through
the neutral conductor. Although nominally it shouldn't be more than a volt
or two, it can rise to 6 volts or more under some legitimate circumstances
(like when my compressor starts). And while 6 volts isn't particularly
dangerous, it can be a problem if, for example, your hands are wet and one
hand is on the refrigerator and the other is on the stove. I have gone out
on installations where the voltage had spikes over 10 volts ! Makes
computers flaky as all get-out ... I came home with 17 blown-up power
supplies and there were only something like 8 computers in the installation.
> It's even
> sillier now on the 220 appliances because you now have to have 4 wires
> instead of three - 2, 120 wires and 1 ground and now lets add
> another ground wire.
The 4th wire is only required on appliances that also need 120v for some
reason (like light bulbs). If it's purely 220v (like a welder) then only 3
conductors are required, there's no need for the neutral.
> Just hook up a wire form the ground screw on the back of the outlet to the
> neutral (white side) on the back of the plug - and you have the exact same
> circuit as if you had hooked the ground wire to the white wire at
> the panel.
Not true ! It's apparently a common misconception that wires are perfect
conductors ... the truth is that they are not perfect conductors, and where
the current flows does make a difference.
> Stick in one of those fancy three light testers and you'll see
> what I mean.
Guess we have a different threshold of "fancy" ... I consider those to be
one of the most basic test tools there is. There is a whole raft of
conditions they don't detect ... you've named only one of them.
Randall
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