| Joel Kamentz 2005-06-17, 11:30 pm |
| I have a farm, so am planning to do most work myself, but call an
electrician for final connection to real juice.
I want to build a shop fairly close to my house. I was planning to run
power from the house to the shop (and have several panels) and then from the
shop to a barn and some other buildings further away.
The barn won't be a very large load -- most commonly lights, but there may
eventually be a water heater for a wash stall. I've already purchased (and
buried) some 4-wire cable to run from the barn (which already exists) to
where the shop will be. I don't remember, but I think the cable was ALU
2/0, though it might have been 1/0. It was definitely rated for direct
burial and is roughly 3' down. I wanted reasonably large cable because of
the chance of installing a water heater. The wire distance from barn to
house is approx 300'.
Since I expect the shop to be a much larger load, I purchased (and buried)
some ALU 4/0. However, it's only 3-wires -- no ground. I was originally
planning to drive ground rods at the shop and at the barn and tie the barn's
ground wire to the barn ground rods at one end and the shop ground rods at
the other end. I (perhaps incorrectly) reasoned that, since the power
company just hooks to ground regularly and gets by with 3 wires instead of 4
that I could do the same thing and not need an actual ground wire running
between service at the house and the panel for the shop. (Distance from
house electrical service to where shop service panel will be is roughly 80')
Someone commented to me once that an actual fourth ground wire might be
necessary to feed the shop, so I'm no longer certain what is the proper way
to wire everything. Also, from lurking here a bit, it seems that, in many
cases, doing one's own grounding (ground rods, etc.) is frowned upon (though
I don't quite understand why).
Q: Should I lay a fourth wire to shop so that house --> shop is four wires
just like shop --> barn?
Q: Should I drive ground rods at barn and shop locations or should I use
four wires everywhere and let everything tie back to the house service and
use whatever ground the house has?
Q: If I need to add a fourth wire between house / shop, should I just get
2/0 ALU to make the set 4/0-4/0-4/0-2/0?
Q: Would it be better to try to get bare wire (ALU or copper) instead of an
insulated one? (It is a ground wire, after all.)
Thanks,
Joel
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