Goedjn wrote:
On 13 Sep 2006 13:52:06 -0700, "matt"
wrote:

grounding bar or lugs should have only bare copper wires only. as long
as the connection is good, it doesnt matter how many grounds per lug.
neutral bar should only have white wires, not doubled up.
breakers or fuses should have only black or red wires, not doubled up.
So you're saying that I really need two ground-busses - one for bare
copper ground wires (doubled up okay), and one for neutral white wires
(but not doubled up)? I think I can do that.

Of course none of my black (hot) wires are doubled up. That seems
common sense, at least to me.


My understanding was that you need keep the ground-buss and the
nuetral-buss separate in sub-panels, but that you can mix and
match in the main service panel, because that's the one and
only place where ground and nuetral are supposed to meet.
(which explains why service panels come with only one buss,
but doesn't explain why there's never enough holes in that buss.)

Further, I was under the impression that whether or not you
can end two wires in any one spot was a function of whether
the connector in question is rated for multiple wires.
Granted that most of them aren't. It SHOULDN'T make
any difference whether the wires in question are
nuetrals, grounds. Either the connection
method is reliable for two wires, and specified that way,
or it's not. (I can see not wanting to mix neutrals
and grounds, on the theory that the pair might come loose
from the buss, but not from each other. That would be bad.)

Likewise, breakers may or may not be rated for two wires
under the screw. I'd expect most not to be, and any that
are should be labled to say so. I'll confess that I can't
think of all that many reasons to WANT to put two wires
under one breaker.

--Goedjn

Goedjn
The reason that some terminals in neutral buss bars are OK for two
Equipment Grounding Conductors (EGCs) but not two Grounded Current
Carrying Conductors (neutrals) is that since neutrals carry current
under normal operating conditions the two neutral conductors might well
be expanding and contracting at different times and to different
degrees. That would cause the connection to loosen over time. EGCs on
the other hand only carry current under fault conditions for a very
brief time so sharing a terminal that is listed for two conductors is
permissible for EGCs but not for neutrals.
--
Tom Horne

"This alternating current stuff is just a fad. It is much too dangerous
for general use." Thomas Alva Edison