Toller wrote:
and then I will be done for a while, really!

I have a Sylvania breaker box, and need to put a common trip quad breaker in
for a new circuit because I am out of room. Two years ago I put in a
Siemens quad, so I know they fit and work; but now can't find one. I need a
C23030CT2. Lowes carries Murray, and while they don't have the one I need,
they have a quad that looks to be identical to the Siemens. Are they the
same? The Murray I need is a MP230230CT2, and seem to be readily available.

Don't know them specifically, but should be rated/listed for
interchange if it is. A electrical service distributorship will have
the data sheets/catalogs that will tell if you'll go there instead of
the Borg's.

(I am tempted to pull out three circuits going to my workshop and put a
subpanel in, rather than putting in the fourth circuit. I sure wish I had
done it that way originally.)

I'd recommend it as a far cleaner solution and agree w/ the "rue the
day" sentiment. If's almost always better to plan ahead for growth and
who knows--you may want something yet again one day and then be stuck
for certain.

I intend on running 10/2AC or 10/2MC. The AC is $0.60/ft, and the MC is
$1.10/ft. What about the MC is worth nearly twice the price? I don't want
to waste $50, but I "save" $50 by buying a product that will be much
inferior.

"Inferior" is hardly the word here, they're designed for differening
purposes/applications. Where is the run and what is needed for it is
the question to answer, then buy the appropriate cable. You might look
here for MC description and then find the AC and compare. (Google is
your friend )

http://www.southwire.com/Southwire/S...alog_pages.pdf
That's all, thanks.