"BIOSMonkey" wrote in message
...
More questions:

1) In order to add enough circuits in my breaker box, I may have to double
up
some of the breakers. We had a new heat pump system installed and the
HVAC guys
stole a lot of space!

I really only have one breaker space left, and 2 more circuits to run (1
20A for
bathroom and 2 15A for bedrooms), BUT some of the other breakers are
single and
could potentially be converted to two small breakers. What are the rules
regarding this? I am wondering why some are single and some are
double...why
not just make all of them double to leave space?

When you buy a box, its listed max capaciy usually is with double breakers.

In most later model boxes, a double breaker will be fed by one phase of the
240V. In some older boxes the double breaker might actually be fed by both
phases (as if they were seperate breakers). This differentiation really
only becomes important if you are using 3 conductor romex and trying to use
one neutral for two hot branches. In that case, the two branches should be
fed by different phases in the breaker box. If all your branch circuits are
wired on 12-2 romex, you probably don't have to worry about which phase you
are connecting to.

Run 20A to the bedroom unless the wire is 14# If you have 12# wire give it
all the juice it deserves. In many areas, AFCI breakers are required for
bedrooms. These usually only come in full slot size (no doubles). AFCI are
not available in receptacles like GFCI and must be in the box. Check your
city to know if it is required. I like GFCI in the bedroom also.



2) Does the bathroom circuit have to be dedicated to the GFCI outlet ONLY
or can
it also feed the vanity lights?

If you trip the breaker, you'll be fishing around in the dark looking for
the reset. Not sure of the code on that one. Can wire the light to the
bedroom lighting ckt. If the fixture has a plug, it should be GFCI also.

3) Can NM cable be run diagonally under the joists, or must it follow the
inside
of the joist or through holes? (remember I will be doing a drop ceiling)

If the joists are in an inaccessable area not likely to be touched or
stepped on, it would be OK. If the cieling is suspended in such a way that
one could not put a nail through a cable it should be OK. Concieling the
wire is a better practice. Check with your city, they might want you to use
armored cable in that situation.

The little "Code Check Electrical" book is a very concise resource
containing all the answers you seek and can be purchased at most big box
hardware stores.