DIYbanter - View Single Post - Wiring 3 way switches for detatched garage lights

wrote:
No insult taken, I posted to learn. Your right on the THWN, and most
THHN is also rated as THWN (which mine is). Interestingly I do have a
building permit and the electrical inspector is the one who showed me
the code on being able to run 2-2-4AL with a grounding rod at the
garage. My original intent was 2-2-2-4AL, but he convinced me
otherwise and showed me the code which supported it (no metal pipes
shared between buildings)

I could be mistaken, but you mentioned the ground wire should be white?
I thought that it should always be green if possible.?

I'm sure your inspector meant well but the prohibition against other
metallic pathways between the two buildings includes those lighting
switch circuits or any other wiring besides the feeder itself. If you
run a ground with your switching circuits it will end up carrying
neutral current in parallel with the neutral of the feeder. If you
don't run a ground with the switching circuits you will have a poor
fault clearing pathway for those circuits because the Equipment
Grounding Conductors (EGCs) for the garage will be bonded at the
building disconnecting means to the neutral of the garage feeder and the
EGCs for the house are bonded to the neutral of the power company supply
at the service disconnecting means for the entire premise. That may
make for an excessively long fault path. You would also never be able
to run an extension telephone, intercom, alarm circuit, video cable, nor
any other conductive pathway between the garage and the house. In order
to have a fully safe and efficient system to supply power to your garage
I'd suggest that you run a separate EGC in the feeder and use it to
provide the fault clearing pathway for all of the garage's wiring.
--
Tom Horne

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