Ecnerwal wrote:
Hey, it's on topic - lots of metal in long squiggly bits, and it's going
to my shop...

I'm throwing 300 amp service (one phase, all there is out in the woods)
at my new shop building, having finally gotten past various hurdles that
caused me to think for a long time I was going to have to make it be
off-grid. Eventually 100 amps will come off that to the eventual house,
if that ever eventually happens.

It's about 335 feet of run, plus running from the pole-mount transformer
to down in the ground, and back up to the meter at the far end. It's on
the cusp of 400 or 500 MCM copper, and I'm probably just going 500 to be
sure. Can't run primary underground per the power company rules (I
can't. They can, but they won't, or they price it so high that I won't,
comes to the same thing in the end). Something like 370-390 feet of wire.

Conduit figures to 3" min, I'm thinking 4" - not only more room, but
possibly one of those bigger is not more expensive (might even be
cheaper?) if it's the more common size things - don't know for sure.
Yes, I'll be dropping in some spares while I have the hole open. Well,
at least some extras - the price I'm being estimated on the large
conduit (PVC) seems high - $5/foot? The 4" plumbing stuff is only about
$2/foot last I recall, and while I expect electrical to cost a bit more,
more than double seems high. That may preclude a spare for the big
stuff. At least one empty smaller run as well as the phone line run.

Anyway, while I'm pondering prices, does $5.67/foot sound like a
reasonable price for 500 MCM copper when buying 1100-1200 feet (370-390
X3)? My electrician has been saying his suppliers have cut prices
drastically with the slowdown in building and/or China (depending what
you think drives copper prices more), but only got to specifics once the
run length was nailed down.

I've saved Bruce's previous advice about getting copper bus bars in the
breaker box and making sure it's industrial interchange, rather than
some oddball custom breakers. What other advice have I forgotten, before
it's too late? I don't know that an air line in the trench makes a lot
of sense, as the trench terminates halfway up the driveway. I should be
able to tie the ground network into a 100 foot well casing. Should I run
a ground all around the outside of the building, and if so, is #4
adequate for that? Too late for a Ufer on this building.

I do have a licensed electrician working on this, but I value a second
opinion...it's a big chunk of the building fund on one aspect.

Leave an extra pull cord in the conduit if
you can. It will probably be all rotten
and tangled if you need it, but who knows..