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Posted by Thomas D. Horne, FF EMT on August 27, 2006, 9:58 pm
powercat@verizon.net wrote:
> NEC requires an electrical disconnect at the service entrance to an
> outbuilding when fed from a main located elsewhere on the property. In
> addition to the two hots, the subpanel in the separate structure need
> to have the neutral and the ground also connected to the main panel (in
> most areas of the US this means whether or not you have a separate
> grounding point for the subpanel).
>
> Now here's my question. In the newest NEC book from 2005 there is some
> screwy language about being able to disconnect all of the wiring at the
> mechanical disconnect. I showed this to my friend a retired
> electrician who wonders if it was written in English.
>
> Has anyone seen a mechanical disconnect that is a true (i.e. four wire)
> disconnect for a structure? All the ones I have ever seen are
> three-wire disconnects and don't disconnect the grounding portion.
>
The code only requires the simultaneous disconnection of all UNGROUNDED
conductors. It specifically forbids the disconnection of the Grounded
Current Carrying Conductor unless that disconnecting means will also
simultaneously open the ungrounded conductors as well.
--
Tom Horne
Well we aren't no thin blue heroes and yet we aren't no blackguards to.
We're just working men and woman most remarkable like you.
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