On Aug 11, 9:29 am, "Leon" wrote:
"Mike Marlow" wrote in message

...


http://www.electrical-online.com/planningacircuit.htm

Do-It-Yourself Repairs and Basic Wiring Projects:
Planning a Circuit

By Terry Peterman, the Internet Electrician
Summary: Planning a circuit in your home requires examining some
basic rules regarding the number of lights permitted on a circuit, and
recommendations for mounting boxes, receptacles and switches.



When planning to hook up a circuit, whether it is a new one directly
from the breaker panel or adding to an existing one, here are some
general rules to follow :

Maximum Lights Per Circuit

You are only allowed to put a maximum of 12 lights on one 15 amp
circuit, but try for between 8 and 10, if you are combining
receptacles and lights.

Remember that switches don't count as outlets. Run a separate circuit
for any large appliances, pumps, and motors etc.

Mounting Boxes

Start by marking the studs where you want your receptacles, switches,
and lights to be located. Then mount your outlet boxes.

Screws are required for octagon boxes but you can use either screws or
nails for switch and receptacle boxes. The important thing to remember
is to make the boxes secure because, once the drywall is on, it's hard
to re-attach them if they do work loose.

Don't forget that you must leave the boxes sticking out from the face
of the stud, slightly less than the thickness of the product that the
wall will be finished with.

Mounting Receptacles

Mount receptacles about 300 mm (12 inches) above the floor. The
general rule is that a receptacle is required for every 3.6 meters (12
feet) of usable wall space.

You are probably curious as to what useable wall space means
exactly...any measurement from the corner of a wall to a closet,
fireplace, or to where the door swings open is considered useable wall
space but, only if the wall is over 900 mm (3 feet) to begin with.

A receptacle is needed every 3.6 meters (12 feet) along a continuous
wall space so that at no time can a cord connected devise be any more
than 1.8 meters (6 feet) from an outlet. Also remember that there is
no maximum number of outlets, so make sure you have enough, and that
they are placed in convenient locations once the room is finished.

Mounting Switches

Mount switches on the inside of rooms opposite to the side that the
door opens. Make them as close as practical to the door opening, but
not so that the cover plate will interfere with the door casing.

The height is fairly flexible, but should be consistent and practical
(any where from 1.1 to 1.3 meters or 44 to 52 inches).

On 12 Aug 2007 08:23:31 GMT, Puckdropper
wrote:


Sometimes I know that I don't know.
;-)

Puckdropper

Then I would say you've advanced to the 2nd level of knowledge on that
particular topic.

1. Don't know that you don't know.
2. Know that you don't know.
3. Know that you know.
4. Don't know that you know.

Tom Veatch
Wichita, KS
USA

Tom Veatch wrote:

| Then I would say you've advanced to the 2nd level of knowledge on
| that particular topic.
|
| 1. Don't know that you don't know.
| 2. Know that you don't know.
| 3. Know that you know.
| 4. Don't know that you know.

This sounds remarkably like a former Secretary of Defense's
semi-coherent ramblings on Middle East intelligence...

--
Morris Dovey
DeSoto Solar
DeSoto, Iowa USA
http://www.iedu.com/DeSoto/SC_Madison.html

In article , duckecho@gmail-dot-com wrote:
On Fri, 10 Aug 2007 14:19:22 -0700, wrote:

[electrical question snipped]

there are about three or four posters here whose electrical
information you can trust. Probably at the top of the list is Doug
Miller. View anyone else's answers with suspicion. I'm surprised he
hasn't posted already. I'm sure he will, however. He can cite the NEC
chapter and verse. Hardly anyone else here can.

Thanks for the endorsement, Rod. I'll try to clarify a few things that seem to
need it, and correct a few things that definitely need it. Would've jumped in
earlier, but I was out of town for the weekend.

"You are only allowed to put a maximum of 12 lights on one 15 amp circuit" --
nonsense. There is no such limitation in the Code for residential
installations. The frequently-claimed limitation on the number of outlets on a
circuit doesn't exist either, for residential installations.

+++++

The discussion so far of the number of conductors in a nn/2 or nn/3 cable has
been only partially correct. Nobody has yet given the complete answer, which
is:

1) In cable intended and approved for use in premises wiring -- NM ("Romex"),
BX, AC, UF, etc. -- the number following the slash *does*not* include
equipment grounding conductors which *may*or*may*not* be present. Thus 12/3
Romex cable contains three insulated 12-gauge conductors (black, red, and
white) and usually contains a fourth conductor, either bare or with green
insulation.

2) In cable intended and approved for use in cord-and-plug connections, the
number following the slash indicates the number of conductors in the cable -
period - without regard to their use. Thus 12/3 Type SJ cable contains three
insulated 12-gauge conductors, usually black, white, and green, and that's
all.

3) The above two categories are mutually exclusive.

+++++

"When a c'bkr is in a panel, it is derated by 20% to handle the panel heat
generated by adjacent c'bkrs.." -- nonsense. Circuit breakers are *required*
by Code to be placed in a panel or other similar fixture [Article 240.30] and
no derating is applied for doing so.

+++++

"#14 can only handle 15*80%=12A on a continuous basis." Correct, but
incomplete and potentially misleading, as it omits the Code definition of a
continuous load: "where the maximum current is expected to continue for 3
hours or more." [Article 100] This is *not* a usual, typical, normal
condition.

+++++

"Either 12/2 or 12/3 will contain a green ground conductor." -- nonsense.
In NM cable (the type used most frequently in residential construction) the
grounding conductor is uninsulated.

+++++

"12/2 would be used for a 240V/1Ph/60Hz service." Correct, as long as it's a
15A or 20A circuit. Higher-current circuits require larger wire.

+++++

Some erroneous statements were made about how 240V circuits need to be wired,
but they've already been adequately corrected by others, and I won't bother to
rehash that.

By the way, just to throw a monkey wrench in the works for all the
oh-so-sure posters about the number of conductors in a cable--it
wasn't so long ago ( in my lifetime and I can personally attest to
it), that if you wanted a ground wire with your Romex (trade name for
NMC or non metallic cable) you had to say "with ground." It was not
implied.

I can attest to that as well.

Granted that's no longer the case, but it does illustrate how
gray an answer can sometimes be. Could be important is some old work.

My advice (and you can take this one to the bank) is don't be
satisfied that you have all the information you need based on the
answers you've received so far.

This is one of those topics that's always sure to generate a lot of traffic,
including a large number of confidently delivered but incorrect answers.
:-)


--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.

On Sun, 12 Aug 2007 12:16:36 -0500, "Morris Dovey"
wrote:

This sounds remarkably like a former Secretary of Defense's
semi-coherent ramblings on Middle East intelligence...

No, it's more like the redneck statement of the three laws of
thermodynamics;

1. You can't win.
2. You can't break even.
3. You can't get out of the game.


Tom Veatch
Wichita, KS
USA

10 or 12 is the wire size, 2 or 3 the number of conductors. All Romex type
cable has a ground which is not referenced as an "official: conductor. 10/3
cable has 3 10awg power carrying conductors and a ground. The 3 conductors
are white (neutral) Black and Red (hots) and is used in balanced 240/120
volt circuits (120 from each hot to neutral, 240 across the hots) 10/2 has
a white and black and is used in 120volt circuits only.

You have 2 issues in wiring a shop, the size of the conductors and the type
of circuits.

Size your conductors based on length of run and branch current rating. 12
awg is standard for 20amp, but I would use 10 for longer runs.

When I designed my shop I ran both general purpose 120volt, 20 namp
circuits and 240volt 20 amp circuits around the shop. the 120s are for the
light stuff, the 240s for larger tools like my lathe, DC etc.

I also ran several dedicated 240volt 50amp or larger circuits for stuff
like welders, compressors etc (Yes, I'm a turncoat, I also work metal!!)

Fri, 10 Aug 2007 14:19:22 -0700, wrote:

In recent posts I have heard mention of 12/2 and 10/2 wire, as well as
12/3 and 10/3 wire. What is the difference and what would you wire a
new shop with?

I assume the 12/2 and 10/2 mean with ground.? What is the extra wire
in the 12/3 and 10/3 for? Is that for wiring 220V?

Jim

On Mon, 13 Aug 2007 00:36:47 -0400, Bradford Chaucer
wrote:

10/2 has a white and black and is used in 120volt circuits only.

Are you saying that I was in error using 10/2 for my 240V water
heater?

I don't think so. There is no requirement to use xx/3 wire for 240V if
a neutral isn't called for (as it is with ranges and dryers since the
'90s). Your table saw or planer circuit could just as correctly be run
with xx/2 cable.

The NEC makes a provision for using the white conductor in NMC (Romex)
as a hot lead for just that circumstance (and also for switching)::
you must mark the white wire at each end as a "hot" conductor. A piece
of tape will do, although I used a red magic marker coloring each
white conductor in all my 240V shop circuits--I could just as easily
have colored them black, as there's no "polarity" marking requirement,
either.

--
LRod

Master Woodbutcher and seasoned termite

Shamelessly whoring my website since 1999

http://www.woodbutcher.net

Proud participant of rec.woodworking since February, 1997

email addy de-spam-ified due to 1,000 spams per month.
If you can't figure out how to use it, I probably wouldn't
care to correspond with you anyway.

In article , wrote:
10 or 12 is the wire size, 2 or 3 the number of conductors. All Romex type
cable has a ground which is not referenced as an "official: conductor. 10/3
cable has 3 10awg power carrying conductors and a ground. The 3 conductors
are white (neutral) Black and Red (hots) and is used in balanced 240/120
volt circuits (120 from each hot to neutral, 240 across the hots)

All correct up to this point, but now you go astray:

10/2 has a white and black and is used in 120volt circuits only.

Completely incorrect. Since a 240V circuit has no neutral conductor, only
two hots and a ground, 10/2 with ground is perfectly fine for use in 240V
circuits up to 30A. Three-conductor cable (such as 10/3) is needed for a 240V
circuit only if there are also 120V loads on the circuit; an example of this
would be an electric dryer, which has 240V heating elements and (typically) a
120V motor. The 240V motors which are typically found in woodworking tools
have no neutral, only two hots, and will get along just fine on circuits wired
with two-conductor cable.

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.

Speaking of useless answers. I went to some trade show years ago. I
got a tote bag that might have said Copper is Proper. I cannot find
the tote bag to see if that was the logo. Two points were made in the
handout and it was geared towards commercial electricians. Well maybe
one point. Copper flows electricity better than aluminum. 12 guage can
be less expensive over the life of a building versus 14 guage due to
lower power losses with the bigger wire. Equipment can run better with
lower voltage drops.

I know copper wire has many advantages over AL wire but I have a question or
two.

First off why is almost all the 'big' wire AL? When I started service here
I was required to buy AL wire to connect the meter to the breaker box on the
pole and to connect that box to the breaker box in the trailer.

Also can you even buy 'small' AL wire, e.g. 10 ga? If so is it that much
cheaper than Cu?

Would anyone here use AL wire for anything?

[electrical question snipped]

You have just been introduced to the hazard of soliciting specialized
advice on the internet.

I'll take that one step further. If a guy has to ask the difference
between 10/2, 10/3. 12/2 etc... WTF is he doing wiring his shop?

I wired my entire place but almost made the same mistake. I almost bought
10/3 because I wanted to have a ground wire.


For chrissakes, call somebody who knows and who has the certification
and insurance!!

And GET A FARKING PERMIT!!

Yes buy all means let's make sure the government gets its pound of flesh. I
paid all the money and got all the permits and did all the work myself. My
final inspection consisted of a guy showing up and sitting in his truck
while we talked about the old PBY flying boat. After about 10 minutes he
signed my paperwork and drove off to do his next inspection.


(Yes, yes, I know, I know... there are many here who have the
knowledge and confidence to do that kind of work themselves, but when
questions indicate a complete and total ignorance of the topic at
hand.........)

A permit ain't going to help that. For onething people like that are the
very ones who don't get permits.

You have always heard there are no stupid questions. Maybe the
questions were asked for reference. To see what others had done when
there shop was wired. I think it was a legitimate question asking the
difference between the wires. If he is to have someone wire the shop
are all electricians going to wire with 12/2 on 220 and 10/2 on 110?
Knowledge is a good thing and being able to tell the electrician what
you want can only make the shop that much better.


One who lacks knowledge on a topic is far better served by telling the
electrician what functionality he wants and leaving the how-to's to the
person most knowledgeable - the electrician. BTW, no - all electricians
are not going to wire with 12/2 on 220 and 10/2 on 110. Just the
opposite. And yes - for the most part, all electricians are going to wire
the same way - based on the requirements of the circuit.

A couple of more points. 1) The more you now about things the easier it is
to calculate your building cost.

2) If you have people bid on a project it helps to know just what they are
planning on using. If Joe's Power bid is lower than Bill's Power its nice
to know that one reason is Joe's is planning on using smaller wire.

Personally, when it comes to wiring bigger IS better. Even more so when it
comes to a workshop. I'm looking at building a new home in a few years and
if I can afford it I will 'over wire' the entire house for a couple of
reasons. First, look around your house now and think about how it looked 10
years ago. How many more electrical items do you have now? How many more
might we have in 10 more years?

Second, its much more difficult to have an electrical fire if you wire a 20
amp breaker with wire that will carry 40 amps or so.

Third, if you need to 'upsize' later its a lot easier to just put in a
larger breaker than putting in new or more wire.

no spam wrote:
Speaking of useless answers. I went to some trade show years ago. I
got a tote bag that might have said Copper is Proper. I cannot find
the tote bag to see if that was the logo. Two points were made in the
handout and it was geared towards commercial electricians. Well maybe
one point. Copper flows electricity better than aluminum. 12 guage can
be less expensive over the life of a building versus 14 guage due to
lower power losses with the bigger wire. Equipment can run better with
lower voltage drops.

I know copper wire has many advantages over AL wire but I have a question or
two.

First off why is almost all the 'big' wire AL? When I started service here
I was required to buy AL wire to connect the meter to the breaker box on the
pole and to connect that box to the breaker box in the trailer.

Also can you even buy 'small' AL wire, e.g. 10 ga? If so is it that much
cheaper than Cu?

Would anyone here use AL wire for anything?

Cost -- compare the price for large diameter Cu vis a vis Al and you'll
see they "why"...

It would be unusual to require Al, most will accept either as most
terminations these days are Cu/Al compatible. If the service gear was
rated for Al only, then it would make sense.

Another reason for Al is that it bends more easily so for larger sizes
it is easier to handle.

Al for service entrance, feeders, etc., sure...

I would expect a very high fraction or more of those "here" have Al in
their own residences in at least those applications.


--

no spam wrote:
....

Third, if you need to 'upsize' later its a lot easier to just put in a
larger breaker than putting in new or more wire.

If you wire for higher ampacity, then may as well install appropriately
sized breakers and outlets, etc., at the time. Otherwise, unless wasted
the extra money for the higher-rated outlets until that unforeseen maybe
never to happen time in the future, placing simply a larger breaker may
be fine for the wiring itself but not for the outlets, etc., ...

--

On Mon, 13 Aug 2007 15:35:37 GMT, "no spam" wrote:



Personally, when it comes to wiring bigger IS better. Even more so when it
comes to a workshop. I'm looking at building a new home in a few years and
if I can afford it I will 'over wire' the entire house for a couple of
reasons.

Yeah, right. My uncle did that when he built his house back in the
'60s. He ran 12 ga to every single device in the house--receptacles,
switches, lights. At the tiime I thought it was a good idea--after
all, it's only one size up, right?

Said he'd never do it again. He nearly crippled himself wiring all
those living room receptacles designed to accommodate a reading lamp
and the bedroom receptacles designed for an alarm clock. To what
purpose? Don't believe me? Go stuff a half dozen boxes with 12 gauge
wire and wire the receptacles. Then do the same with 14 guage wire.
The difference in effort is not trivial.

The shop, on the other hand, is a supportable venture in the larger
wire department. However, unless you're looking at something
significantly greater than say 1000 ft^2 and without a nearby or en
suite load center, you gain virtually nothing by going up a wire size.

If you're running 3HP machines (kind of a regular, home shop size
motor) you don't need any more than a 20A circuit at 240V. If you're
running 5HP you have to go to 30A anyway (and it's more than enough)
so why would you need to go to 40A?

Second, its much more difficult to have an electrical fire if you wire a 20
amp breaker with wire that will carry 40 amps or so.

You can't be serious. It's not nearly as difficult as finding a 15 or
20 amp receptacle into which you can stuff that 8 gauge wire.

You'd be hard pressed working 10 gauge (30A) wire around very many
boxes before you realized what a load of an idea that was. Forget 8
gauge.

Third, if you need to 'upsize' later its a lot easier to just put in a
larger breaker than putting in new or more wire.

Dumb idea #3. The difference in cost between a 20A breaker and 30A
breaker is negligible (they're virtually the same in the Square D QO
line). If you really were commited to running 10 gauge wire throughout
the house (ignoring, for the moment, the difficulty in working it and
the utter lack of need for it) why would you not go ahead and put 30A
breakers in?

All this talk about sizing up electrical circuits is roughly the same
as knot tying by someone who doesn't know how to tie knots--if one
loop is good, two or three must be two or three times better, right?
Hah.

--
LRod

Master Woodbutcher and seasoned termite

Shamelessly whoring my website since 1999

http://www.woodbutcher.net

Proud participant of rec.woodworking since February, 1997

email addy de-spam-ified due to 1,000 spams per month.
If you can't figure out how to use it, I probably wouldn't
care to correspond with you anyway.

In article , "no spam" wrote:

I know copper wire has many advantages over AL wire but I have a question or
two.

First off why is almost all the 'big' wire AL?

Lightweight, and less expensive.

When I started service here
I was required to buy AL wire to connect the meter to the breaker box on the
pole and to connect that box to the breaker box in the trailer.

Required? Really? That's unusual.

Also can you even buy 'small' AL wire, e.g. 10 ga?

Yes.

If so is it that much cheaper than Cu?

Yes.

Would anyone here use AL wire for anything?

Other than as a service entrance, no, not if I can help it.

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.

On Mon, 13 Aug 2007 15:35:36 GMT, "no spam" wrote:

| Speaking of useless answers. I went to some trade show years ago. I
| got a tote bag that might have said Copper is Proper. I cannot find
| the tote bag to see if that was the logo. Two points were made in the
| handout and it was geared towards commercial electricians. Well maybe
| one point. Copper flows electricity better than aluminum. 12 guage can
| be less expensive over the life of a building versus 14 guage due to
| lower power losses with the bigger wire. Equipment can run better with
| lower voltage drops.
|
|I know copper wire has many advantages over AL wire but I have a question or
|two.
|
|First off why is almost all the 'big' wire AL? When I started service here
|I was required to buy AL wire to connect the meter to the breaker box on the
|pole and to connect that box to the breaker box in the trailer.
|
|Also can you even buy 'small' AL wire, e.g. 10 ga? If so is it that much
|cheaper than Cu?
|
|Would anyone here use AL wire for anything?

Cost and weight.

As I stated earlier, the resistivity of Al v. Cu is about 1.5 to 1.7
depending on the alloy. Expressed another way, increasing the Al wire
by approximately two gauge equalizes the losses. (Cu 12 AWG ~ Al 10
AWG)

For residential wiring, the downsides of Al are corrosion, creep and
dissimilar metals issues when connected to copper. The lower wire
cost is eaten up by the specialized connections required to use it.

For overhead long distance transmission lines the cost and weight
advantages of Al are a big deal.

"LRod" wrote in message

Yeah, right. My uncle did that when he built his house back in the
'60s. He ran 12 ga to every single device in the house--receptacles,
switches, lights. At the tiime I thought it was a good idea--after
all, it's only one size up, right?

Your uncle would be right at home in most of the municipalities around here
.... along with the requirement for 5/8" drywall, the minimum wire size
allowed here for _any_ circuit, lights included, is 12ga.

--
www.e-woodshop.net
Last update: 8/8/07
KarlC@ (the obvious)

In article , "no spam" wrote:

Personally, when it comes to wiring bigger IS better.

Nonsense. Except on very long runs, bigger wire provides no advantages at all,
and does provide significant disadvantages:
a) higher cost
b) greater difficulty in installation
c) difficulty in finding compatible receptacles (for example, try finding a
15A rated receptacle that will accept AWG8 wire)
d) the larger the wire, the fewer of them the Code allows you to put in a box.

Even more so when it
comes to a workshop. I'm looking at building a new home in a few years and
if I can afford it I will 'over wire' the entire house for a couple of
reasons. First, look around your house now and think about how it looked 10
years ago. How many more electrical items do you have now? How many more
might we have in 10 more years?

This purpose is achieved much more easily, and at considerably lower cost, by
keeping the wire size the same and increasing the number of circuits.

Second, its much more difficult to have an electrical fire if you wire a 20
amp breaker with wire that will carry 40 amps or so.

Nonsense again. The risk of electrical fire is not significantly greater using
AWG12 wire on a 20A breaker, compared to using AWG8 -- and in fact, you'd
probably be creating a substantial risk of fire by attempting to connect a
standard receptacle to conductors that are too large to fit under the screw
terminals. Sure, you can pigtail the connections -- let me know when you're
getting ready to wire up those receptacles. I want to come watch you stuff
the wires back in the box; I could use a few laughs.

And then I'll phone the local electrical inspector. "Wire that will carry 40
amps or so" is AWG8 or larger. You might want to consult Table 314.16(A) in
the NEC to see how many AWG8 conductors the Code allows you to put in a
standard device box. (Hint: except with the largest device box available, it's
not enough to supply a receptacle -- and forget about feeding through to
another receptacle, or using anything larger than AWG8.)

Third, if you need to 'upsize' later its a lot easier to just put in a
larger breaker than putting in new or more wire.

Nonsense yet again. What, exactly, do you plan to "upsize" to, anyway? It's a
Code violation to put a 20A receptacle on a circuit protected by anything but
a 20A breaker. The larger wire serves no purpose at all.

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.

Doug Miller wrote:
In article , "no
spam" wrote:

....

Also can you even buy 'small' AL wire, e.g. 10 ga?

Yes.

If so is it that much cheaper than Cu?

Yes.
....

I assume somebody must still make it, but out of curiousity I did a
little looking -- lots of feeder and various other larger cable, but I
couldn't find a single reference to 10/x or smaller Al. Smallest I
found was #8.

I'm thinking w/ the Al-wiring scare there simply has been so little
demand for ordinary circuit Al wiring it has become almost, if not, a
thing of the past.

I'm not sure for the smaller gauges the cost differential would be that
great, but maybe, but couldn't find any to try to do a comparison on...

--

In article , dpb wrote:

I assume somebody must still make it, but out of curiousity I did a
little looking -- lots of feeder and various other larger cable, but I
couldn't find a single reference to 10/x or smaller Al. Smallest I
found was #8.

Hmm. Thought I'd seen #10 not too long ago. But then, "not too long ago" is a
longer time period than it used to be, too. :-(

I'm thinking w/ the Al-wiring scare there simply has been so little
demand for ordinary circuit Al wiring it has become almost, if not, a
thing of the past.

I imagine the biggest factor is this:

"Conductors normally used to carry current shall be of copper unless otherwise
provided in this Code." [2005 NEC, Article 110.5]

Exceptions include services and feeders, but not (as far as I can tell) branch
circuits.

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.

Doug Miller wrote:
In article , dpb wrote:

I assume somebody must still make it, but out of curiousity I did a
little looking -- lots of feeder and various other larger cable, but I
couldn't find a single reference to 10/x or smaller Al. Smallest I
found was #8.

Hmm. Thought I'd seen #10 not too long ago. But then, "not too long ago" is a
longer time period than it used to be, too. :-(
I'm thinking w/ the Al-wiring scare there simply has been so little
demand for ordinary circuit Al wiring it has become almost, if not, a
thing of the past.

I imagine the biggest factor is this:

"Conductors normally used to carry current shall be of copper unless otherwise
provided in this Code." [2005 NEC, Article 110.5]

Exceptions include services and feeders, but not (as far as I can tell) branch
circuits.

I started to say I thought the Code _might_ have removed AL from branch
circuit use, but wasn't sure enough to say so (and didn't feel like
digging through to find out for sure).

That pp would certainly put a crimp in the market, wouldn't it?

So, at least for all practical purposes, the answer to the question of
is AL in smaller sizes (for electrical wiring purposes) available is "No"...

--

On Fri, 10 Aug 2007 14:19:22 -0700, wrote:

In recent posts I have heard mention of 12/2 and 10/2 wire, as well as
12/3 and 10/3 wire. What is the difference and what would you wire a
new shop with?

I assume the 12/2 and 10/2 mean with ground.? What is the extra wire
in the 12/3 and 10/3 for? Is that for wiring 220V?

So, with 60+ (sometimes contentious) posts and not a peep from the OP,
does anyone else get that sharp pain in the cheek feeling that comes
from striking the lure?


--
LRod

Master Woodbutcher and seasoned termite

Shamelessly whoring my website since 1999

http://www.woodbutcher.net

Proud participant of rec.woodworking since February, 1997

email addy de-spam-ified due to 1,000 spams per month.
If you can't figure out how to use it, I probably wouldn't
care to correspond with you anyway.

Doug Miller wrote:
In article , "no
spam" wrote:

Personally, when it comes to wiring bigger IS better.

Nonsense. Except on very long runs, bigger wire provides no
advantages at all,
and does provide significant disadvantages:
a) higher cost
b) greater difficulty in installation
c) difficulty in finding compatible receptacles (for example, try
finding a 15A rated receptacle that will accept AWG8 wire)
d) the larger the wire, the fewer of them the Code allows you to put
in a box.


Just curious.....aren't most electrical fires related to junctions,
switches, receptacles and things plugged into them? In other words aren't
strait wire runs the least problematic of any potential electrical fault as
well? Rod

"dpb" wrote in message ...
no spam wrote:
Speaking of useless answers. I went to some trade show years ago. I
got a tote bag that might have said Copper is Proper. I cannot find
the tote bag to see if that was the logo. Two points were made in the
handout and it was geared towards commercial electricians. Well maybe
one point. Copper flows electricity better than aluminum. 12 guage can
be less expensive over the life of a building versus 14 guage due to
lower power losses with the bigger wire. Equipment can run better with
lower voltage drops.

I know copper wire has many advantages over AL wire but I have a question
or two.

First off why is almost all the 'big' wire AL? When I started service
here I was required to buy AL wire to connect the meter to the breaker
box on the pole and to connect that box to the breaker box in the
trailer.

Also can you even buy 'small' AL wire, e.g. 10 ga? If so is it that much
cheaper than Cu?

Would anyone here use AL wire for anything?

Cost -- compare the price for large diameter Cu vis a vis Al and you'll
see they "why"...

IIRC, you can use a smaller Cu wire.


It would be unusual to require Al, most will accept either as most
terminations these days are Cu/Al compatible. If the service gear was
rated for Al only, then it would make sense.

I just know what the permit people told me. I guess you can't buy a Cu
rated meter box.


I would expect a very high fraction or more of those "here" have Al in
their own residences in at least those applications.

I missed a word. It should read: Would anyone here use AL wire for anything
else? That is would anyone here use AL wire from the breaker box to the
outlets.

Third, if you need to 'upsize' later its a lot easier to just put in a
larger breaker than putting in new or more wire.

If you wire for higher ampacity, then may as well install appropriately
sized breakers and outlets, etc., at the time. Otherwise, unless wasted
the extra money for the higher-rated outlets until that unforeseen maybe
never to happen time in the future, placing simply a larger breaker may be
fine for the wiring itself but not for the outlets, etc., ...

True but I was thinking of being able to add more outlets to the same line.
Example when I bought my last house there was one outlet along the wall were
I wanted to put my entertainment center I had to use 2 power strips. No big
deal there because nothing was drawing much power and very few of the items
were on at any one time. But what if in the future things need more power?
I'm guessing they will. Its a lot easier to put an outlet or two on an
existing circuit than it is to run an entire new line from the breaker box.
Who know what we will need in 10 years. Its a bit more than 10 years old
but the house mom lives in had a total of 6 fuses when it was built!! I
think when we remodeled it we added 6 more circuits, with fuses so you can
tell that's been a while ago.

I might change my mind when I start building. But right now its going to be
an over wired, concrete dome with metal studs and fiberglass backed
wallboard. I'm a bit paranoid about fire so there will be very few
flammable building materials used in it.

Personally, when it comes to wiring bigger IS better. Even more so when
it
comes to a workshop. I'm looking at building a new home in a few years
and
if I can afford it I will 'over wire' the entire house for a couple of
reasons.

Yeah, right. My uncle did that when he built his house back in the
'60s. He ran 12 ga to every single device in the house--receptacles,
switches, lights. At the tiime I thought it was a good idea--after
all, it's only one size up, right?

Said he'd never do it again. He nearly crippled himself wiring all
those living room receptacles designed to accommodate a reading lamp
and the bedroom receptacles designed for an alarm clock. To what
purpose? Don't believe me? Go stuff a half dozen boxes with 12 gauge
wire and wire the receptacles. Then do the same with 14 guage wire.
The difference in effort is not trivial.

I'm not sure what you mean. Are you saying that its tough to have three 10
ga wires coming into one box or are you saying its hard to work 10 ga wire?
Other than 3 way lights why would you have that many wires and a swith or
outlet in one box? I've put in a several 220VAC outlets into regular boxs
(the kind you use to power portable 220 heaters) using 10ga copper. Stiff
but not that bad.


The shop, on the other hand, is a supportable venture in the larger
wire department. However, unless you're looking at something
significantly greater than say 1000 ft^2 and without a nearby or en
suite load center, you gain virtually nothing by going up a wire size.

If you're running 3HP machines (kind of a regular, home shop size
motor) you don't need any more than a 20A circuit at 240V. If you're
running 5HP you have to go to 30A anyway (and it's more than enough)
so why would you need to go to 40A?

The shop I'm WANTING to build will be large enough to get a tractor trailer
rig into with the doors shut. It'll have a woodworking area, a metal
working area, storage for my little farm tractor and its stuff as well as an
area for working on vehicles. The last time I drew it using a computer
building program it was something 60' X 80'.

Of course the shop I'm probably going to wind up with will be somewhat
smaller. Big enough I can get the truck in and JUST be able to shut the
doors and that after I move my tractor, bush hog and the like out.


Second, its much more difficult to have an electrical fire if you wire a
20
amp breaker with wire that will carry 40 amps or so.

You can't be serious. It's not nearly as difficult as finding a 15 or
20 amp receptacle into which you can stuff that 8 gauge wire.

Only slightly. Try 15 amp breaker with 20 amp wire. Of course the weakness
I have found in the entire system is the outlet itself. Wires work loose or
bad contacts cause arcing which cause fires.


Third, if you need to 'upsize' later its a lot easier to just put in a
larger breaker than putting in new or more wire.

Dumb idea #3. The difference in cost between a 20A breaker and 30A
breaker is negligible (they're virtually the same in the Square D QO
line). If you really were commited to running 10 gauge wire throughout
the house (ignoring, for the moment, the difficulty in working it and
the utter lack of need for it) why would you not go ahead and put 30A
breakers in?

The house is still at least 3 years from being started so I might if there
isn't that much difference in price and the code Nazis allow it I probably
will. After dealing with them just trying to put in a trailer I hate to
think about the rules they have for wiring a new house.

I'm also going to do other 'dumb' things. Here's just a few. I'll run at
least one 220VAC to each room and put in an outlet. My old house had a
couple and I found that a portable 220VAC heater (which I still have a few)
can make a room nice and warm quickly w/o needing to crank the heat in the
entire house. I'll run 1" water lines from the pump to the house. The
heating and cooling will be suplmented, hopefully totally ran, by a home
built solar thermal system (yes I'll be making cold air using heat from the
sun). I'll use metal studs and beams. The wallboard will have fiberglass,
not paper, backing.


All this talk about sizing up electrical circuits is roughly the same
as knot tying by someone who doesn't know how to tie knots--if one
loop is good, two or three must be two or three times better, right?
Hah.

That's me. If at all possible I put a double half hitch behind a bowline,
use 500# rated line to lift 200# and put one more tie down if there's room.
I also don't work under anything that is only supported by hydraulic
cylinders. Don't work around flamable items w/o a fire extinguisher near
by. BTW, I have a fire X in the kitchen, one in each car/truck and one on
my tractor. Don't drive w/o my seatbelt nor ride a motorcycle w/o a helmet.
All of this and then some. None of those take much more time nor money and
can save money and even a life if something goes wrong.

But I don't want to make you do any of that if you don't want to.

no spam wrote:
"dpb" wrote in message ...
no spam wrote:
Speaking of useless answers. I went to some trade show years ago. I
got a tote bag that might have said Copper is Proper. I cannot find
the tote bag to see if that was the logo. Two points were made in the
handout and it was geared towards commercial electricians. Well maybe
one point. Copper flows electricity better than aluminum. 12 guage can
be less expensive over the life of a building versus 14 guage due to
lower power losses with the bigger wire. Equipment can run better with
lower voltage drops.
I know copper wire has many advantages over AL wire but I have a question
or two.

First off why is almost all the 'big' wire AL? When I started service
here I was required to buy AL wire to connect the meter to the breaker
box on the pole and to connect that box to the breaker box in the
trailer.

Also can you even buy 'small' AL wire, e.g. 10 ga? If so is it that much
cheaper than Cu?

Would anyone here use AL wire for anything?
Cost -- compare the price for large diameter Cu vis a vis Al and you'll
see they "why"...

IIRC, you can use a smaller Cu wire.

But the comparison of the required Cu to that for Al for the same
current rating still favors Al in a sizable ratio.


It would be unusual to require Al, most will accept either as most
terminations these days are Cu/Al compatible. If the service gear was
rated for Al only, then it would make sense.

I just know what the permit people told me. I guess you can't buy a Cu
rated meter box.

I'm sure they were simply telling you to do common practice. Al is the
de facto standard for feeder/service use.


I would expect a very high fraction or more of those "here" have Al in
their own residences in at least those applications.

I missed a word. It should read: Would anyone here use AL wire for anything
else? That is would anyone here use AL wire from the breaker box to the
outlets.

See Doug's response -- w/ NEC 2005 at least it isn't allowed.

--

In article , "Rod & Betty Jo" wrote:
Doug Miller wrote:
In article , "no
spam" wrote:

Personally, when it comes to wiring bigger IS better.

Nonsense. Except on very long runs, bigger wire provides no
advantages at all,
and does provide significant disadvantages:
a) higher cost
b) greater difficulty in installation
c) difficulty in finding compatible receptacles (for example, try
finding a 15A rated receptacle that will accept AWG8 wire)
d) the larger the wire, the fewer of them the Code allows you to put
in a box.


Just curious.....aren't most electrical fires related to junctions,
switches, receptacles and things plugged into them? In other words aren't
strait wire runs the least problematic of any potential electrical fault as
well? Rod

Exactly right in all respects, Rod.

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.

In article , "no spam" wrote:

I'm not sure what you mean. Are you saying that its tough to have three 10
ga wires coming into one box or are you saying its hard to work 10 ga wire?

Both.

10ga wire is *much* harder to work with than 12ga. And Code doesn't allow as
many conductors in a box.

Other than 3 way lights why would you have that many wires and a swith or
outlet in one box?

It's common practice for receptacle boxes to be daisy-chained, with each box
but the last on the run having two cables, power in and power out. That means
four conductors. For the purposes of calculating the required space in the
box, Code requires you to add one for the equipment grounding conductors, two
for the receptacle, and one for each cable clamp. That's eight in all -- times
2.25 cu in for 12ga conductors, or 2.50 cu in for 10ga. And that makes the
difference between being Code-compliant (with 12ga conductors in the largest
standard device box available) and being a violation with 10ga conductors in
*any* single-gang device box.

I've put in a several 220VAC outlets into regular boxs
(the kind you use to power portable 220 heaters) using 10ga copper. Stiff
but not that bad.

Now try doing an entire living room's worth of receptacles and switches, say
eight or ten devices. How do your hands feel after that?
Second, its much more difficult to have an electrical fire if you wire a 20
amp breaker with wire that will carry 40 amps or so.

You can't be serious. It's not nearly as difficult as finding a 15 or
20 amp receptacle into which you can stuff that 8 gauge wire.

Only slightly. Try 15 amp breaker with 20 amp wire. Of course the weakness
I have found in the entire system is the outlet itself. Wires work loose or
bad contacts cause arcing which cause fires.

Exactly -- the weakness is in the outlet, and in the connections to it. There
is no practical benefit from using larger wire.


Third, if you need to 'upsize' later its a lot easier to just put in a
larger breaker than putting in new or more wire.

Dumb idea #3. The difference in cost between a 20A breaker and 30A
breaker is negligible (they're virtually the same in the Square D QO
line). If you really were commited to running 10 gauge wire throughout
the house (ignoring, for the moment, the difficulty in working it and
the utter lack of need for it) why would you not go ahead and put 30A
breakers in?

The house is still at least 3 years from being started so I might if there
isn't that much difference in price and the code Nazis allow it I probably
will. After dealing with them just trying to put in a trailer I hate to
think about the rules they have for wiring a new house.

15A or 20A rated receptacles on a circuit with a 30A (or larger) breaker is a
violation.

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.

In article , "no spam" wrote:

Third, if you need to 'upsize' later its a lot easier to just put in a
larger breaker than putting in new or more wire.

If you wire for higher ampacity, then may as well install appropriately
sized breakers and outlets, etc., at the time. Otherwise, unless wasted
the extra money for the higher-rated outlets until that unforeseen maybe
never to happen time in the future, placing simply a larger breaker may be
fine for the wiring itself but not for the outlets, etc., ...

True but I was thinking of being able to add more outlets to the same line.
Example when I bought my last house there was one outlet along the wall were
I wanted to put my entertainment center I had to use 2 power strips. No big
deal there because nothing was drawing much power and very few of the items
were on at any one time. But what if in the future things need more power?
I'm guessing they will. Its a lot easier to put an outlet or two on an
existing circuit than it is to run an entire new line from the breaker box.

Of course it is. But if you increase the breaker size past 20A, every single
one of your outlets turns into a Code violation.

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.

"Doug Miller", self declared electrical genius wrote:

+++++

"When a c'bkr is in a panel, it is derated by 20% to handle the panel heat
generated by adjacent c'bkrs.." -- nonsense. Circuit breakers are
*required*
by Code to be placed in a panel or other similar fixture [Article 240.30]
and
no derating is applied for doing so.

Name plate ratings of molded case thermal-magnetic c'bkrs are for bkrs in
free air.

As soon as the bkr is placed in an enclosure, detating applies.

Take your meds and go read your code book again, this time try to understand
what you read.

+++++

"#14 can only handle 15*80%=12A on a continuous basis." Correct, but
incomplete and potentially misleading, as it omits the Code definition of
a
continuous load: "where the maximum current is expected to continue for 3
hours or more." [Article 100] This is *not* a usual, typical, normal
condition.

Three (3) hours doesn't meet the definition of "continuous" in my world.

Lew

In article , "Lew Hodgett" wrote:
Doug Miller wrote:
+++++

"When a c'bkr is in a panel, it is derated by 20% to handle the panel heat
generated by adjacent c'bkrs.." -- nonsense. Circuit breakers are *required*
by Code to be placed in a panel or other similar fixture [Article 240.30] and
no derating is applied for doing so.

Name plate ratings of molded case thermal-magnetic c'bkrs are for bkrs in
free air.

As soon as the bkr is placed in an enclosure, detating applies.

Got a Code cite for that?

I didn't think so.

"#14 can only handle 15*80%=12A on a continuous basis." Correct, but
incomplete and potentially misleading, as it omits the Code definition of a
continuous load: "where the maximum current is expected to continue for 3
hours or more." [Article 100] This is *not* a usual, typical, normal
condition.

Three (3) hours doesn't meet the definition of "continuous" in my world.

The definition of "continuous" in your world, wherever that may be, is
irrelevant. The only meaningful definition, for purposes of determining Code
compliance, is that provided by Article 100 of the NEC: "a load where the
maximum current is expected to continue for 3 hours or more."

And *that* is where the 20% derating applies: to continuous loads as defined
by the NEC. Not as defined by Lew.

Now go take your meds and read your code book again. This time try to
understand what you read.

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.

"no spam" wrote in
. net:

*snip*


Personally, when it comes to wiring bigger IS better. Even more so
when it comes to a workshop. I'm looking at building a new home in a
few years and if I can afford it I will 'over wire' the entire house
for a couple of reasons. First, look around your house now and think
about how it looked 10 years ago. How many more electrical items do
you have now? How many more might we have in 10 more years?


*snip*


Third, if you need to 'upsize' later its a lot easier to just put in a
larger breaker than putting in new or more wire.



That was my theory with my LAN. When I was initially building it, I
decided to go with Cat 5 cable capable of 100 mbs, and only get a hub
capable of 10 mbs. When the prices came down on 100 mbs switches, all I
had to do was unplug one and plug in the new one.

Puckdropper
--
Wise is the man who attempts to answer his question before asking it.

To email me directly, send a message to puckdropper (at) fastmail.fm

"Bradford Chaucer" wrote in message
...
10 or 12 is the wire size, 2 or 3 the number of conductors. All Romex
type
cable has a ground which is not referenced as an "official: conductor.
10/3
cable has 3 10awg power carrying conductors and a ground. The 3 conductors
are white (neutral) Black and Red (hots) and is used in balanced 240/120
volt circuits (120 from each hot to neutral, 240 across the hots) 10/2
has
a white and black and is used in 120volt circuits only.

This is just patently incorrect. Perhaps it's a typo, but in matters like
this good proof reading becomes essential. 10/2 is not used in 120v
circuits only.



--

-Mike-

On Tue, 14 Aug 2007 11:40:26 -0400, "Mike Marlow"
wrote:


"Bradford Chaucer" wrote in message
.. .
10 or 12 is the wire size, 2 or 3 the number of conductors. All Romex
type
cable has a ground which is not referenced as an "official: conductor.
10/3
cable has 3 10awg power carrying conductors and a ground. The 3 conductors
are white (neutral) Black and Red (hots) and is used in balanced 240/120
volt circuits (120 from each hot to neutral, 240 across the hots) 10/2
has
a white and black and is used in 120volt circuits only.

This is just patently incorrect. Perhaps it's a typo, but in matters like
this good proof reading becomes essential. 10/2 is not used in 120v
circuits only.

Actually, I'd be surprised if 10/2 was used in 120V circuits at all.


--
LRod

Master Woodbutcher and seasoned termite

Shamelessly whoring my website since 1999

http://www.woodbutcher.net

Proud participant of rec.woodworking since February, 1997

email addy de-spam-ified due to 1,000 spams per month.
If you can't figure out how to use it, I probably wouldn't
care to correspond with you anyway.

Puckdropper wrote in
reenews.net:

"no spam" wrote in
. net:

*snip*


Personally, when it comes to wiring bigger IS better. Even more so
when it comes to a workshop. I'm looking at building a new home in a
few years and if I can afford it I will 'over wire' the entire house
for a couple of reasons. First, look around your house now and think
about how it looked 10 years ago. How many more electrical items do
you have now? How many more might we have in 10 more years?


*snip*


Third, if you need to 'upsize' later its a lot easier to just put in
a larger breaker than putting in new or more wire.



That was my theory with my LAN. When I was initially building it, I
decided to go with Cat 5 cable capable of 100 mbs, and only get a hub
capable of 10 mbs. When the prices came down on 100 mbs switches, all
I had to do was unplug one and plug in the new one.

Puckdropper

An entirely different kettle of fish. The wire you used is part of the
standard for both speeds, and maybe others, and works pretty easily for
the setup you describe.

Which is pretty much exactly what was discussed back in the early to
mid-90's when all of this started to come together...

Patriarch,
who did the same thing, really...

In article , duckecho@gmail-dot-com wrote:
On Tue, 14 Aug 2007 11:40:26 -0400, "Mike Marlow"
wrote:


"Bradford Chaucer" wrote in message
. ..
10 or 12 is the wire size, 2 or 3 the number of conductors. All Romex
type
cable has a ground which is not referenced as an "official: conductor.
10/3
cable has 3 10awg power carrying conductors and a ground. The 3 conductors
are white (neutral) Black and Red (hots) and is used in balanced 240/120
volt circuits (120 from each hot to neutral, 240 across the hots) 10/2
has
a white and black and is used in 120volt circuits only.

This is just patently incorrect. Perhaps it's a typo, but in matters like
this good proof reading becomes essential. 10/2 is not used in 120v
circuits only.

Actually, I'd be surprised if 10/2 was used in 120V circuits at all.

There would be a few rare cases, such as
- very long run on a 20A circuit, where voltage drop is a legitimate concern
- 30A circuit supplying, for example, fixed space heating equipment
but I'm sure that its most common use, by far, is in 240V circuits.

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.

In article ,
"Mike Marlow" wrote:

This is just patently incorrect. Perhaps it's a typo, but in matters like
this good proof reading becomes essential. 10/2 is not used in 120v
circuits only.

Right. It makes dandy speaker wire.

On Tue, 14 Aug 2007 15:48:08 +0000, LRod
wrote:
[snip]
|
|Actually, I'd be surprised if 10/2 was used in 120V circuits at all.

Very common in the recreational vehicle world. Let me rephrase...120V,
30A circuits are very common in the RV world. (What wire size they use
is unknown) Most RV parks provide 30A hookups; with some supplying
50A circuits for "big rigs", those with dual A/C, washer/driers, etc.

I want to thank all the posters for the information. I have read
everyone post and appreciate the time and effort in answering the
question. I meet with the electrician next week in wiring the shop.

Thank you.

Jim