Doug Miller wrote:

3/4" is overkill for most NM cabling. 1/2" is ample for one or two 14-2 or one
14-3; 5/8" quite sufficient for one or two 12-2 or one 12-3. Why bother
drilling smaller holes, you may ask? It's faster. And it doesn't drain the
battery in your cordless drill as quickly.

I like the idea of putting two 12-2 cables through one 5/8" hole. It
goes without saying that safety is my highest priority.

What is an ideal hole size for a single 10-2 cable? 3/4"? Similar
distance between adjacent holes?


It is good that no feet will be able to stretch the wire, but I think it
should be protected so that no one can push a box against it as well.

Correct.

I have seen the idea of building a "U-shaped" running board proposed.

Not necessary. Why make more work for yourself?

Hmmm...attaching it low (close to the eaves) seems to offer the running
board the safest reasonable location. BTW, it will be approximately 12
feet long. Surely I don't wish to clutter the area directly over the
existing main and the new adjacent subpanel more than it already is.
Presently wires "spew" from the top plate over the main panel . So, I
will strive that my new work will not impede access. What is a good way
to add protection against the above-mentioned box that someone might be
inclined to push against the running board? A gun? : )




6 cables across an 6"-8" wide board?

No problem. A 1x6 should be fine.




I don't think you've considered the difficulty of attaching
the boards with half a dozen cables hanging off of them....

You are correct (but I can imagine worse, I think)!


3) Why bother with the plastic-backed staples? Code permits plain metal
staples such as these
http://www.amazon.com/NM-Cable-Stapl.../dp/B002CM2IPY
which are much cheaper, and *far* easier to install.


Hmm. I've noticed those in my present configuration. Intuitively, plain
metal staples seem to increase the risk of accidentally damaging the
cabling. Someone suggested that they used insulated staples with nm
cable. I will seek to better understand these options. I don't mind
spending a few dollars on staples if it makes installing cable more
idiot-proof, in case I have a helper! : )



We discussed outlet locations (in proximity to panels) earlier.
My main panel is 24" to the right of the back door of the garage. Is
there any problem with installing a duplex outlet in between the panel
and the back door, at 50" high? My concern was that the location was
where someone might expect to find a light switch (so I would use a
coverplate, or equivalent protection). Does the NEC prohibit what I
have suggested?

Thank you very much!

BTW, most of the drywall on Wall #2 is coming off tomorrow. I may try to
speed things up with careful use of my reciprocating saw. I hope I can
get to sleep! : )