[SML] wire colors

[e-mail frank.wood95]

On 29 June 2015 at 20:02, Bill Nelson via Stagecraft
<stagecraft at theatrical.net> wrote:
>>> He may have specified what is a "shared neutral" configuration - which is
>>> not the same as "ground and neutral are the same thing".

I don't understand what you mean by the term "shared neutral". In my
book, the neutral is the star point of a three-phase star connected
supply. The neutral wire carries only the 'out-of-balance' current.
>>
>> Well, yes and no.  The result of his design was a 4-pin connector,
>> with 3 3-Ø hot conductors, and one neutral shared among them.  The
>> "consultant" said to me, word-for-word, "Ground and neutral are the
>> same thing."  We did find that the metal cover of the floor pocket was
>> mechanically grounded back to the distro panel via the conduit, which
>> helped somewhat when exhibitors had modern electronic gear like sound
>> systems or computers.

Your 'consultant' needs his head seen to. Four wires are needed for a
three-phase star connection, but an earth connection is also needed.
It is possible to obtain this through the conduit, but it is not
really reliable. Remember that instantaneous fault currents can be
several thousand amperes, albeit for a very short time.




-- 
Frank Wood