Aluminium house wiring

[charby]

The largest rolls Home Depot sells are 250 feet.

Shop elsewhere, you should find at least 500' rolls at big box hardware stores.

Also

You will need 12/3 for any three way circuits. Please don't do 14/2, upgrade now, if you are going to do 14/2 just stick with the aluminum.

Then you can feel confident about putting a window AC until or dehumidifier in any outlet in the house.

If you are trying to be cheap, only use the 14/2 for the light fixtures.

[charby]

Also you don't need to do it all in one weekend, do it a room/circuit at a time. It will take you longer than a weekend to do your entire house. Probably 3-4 weekends.

Home Depot sells 1000' rolls, may have to order for your store.

http://www.homedepot.com/p/Southwire-Romex-SIMpull-1-000-ft-12-2-Type-NM-B-Cable-28828201/202316226#.UdM647Eo5aQ

You could buy wire as you have money, are you replacing the outlets, fuses or fixtures? Those can be expensive when buying a lot of them.

[CNYCacher]

You can even put 15A duplex receptacles on a 20A circuit.

 

Had to look this up.  Makes sense now.

[zahc]

So, what's always confused me is that installing 20amp circuits makes the breaker less likely to trip. This actually seems less safe to me. It has been explained to me that the circuit breakers are only intended to protect the installed wiring and not the end equipment nor the user. But Whenever i've had breakers trip, it has usually been some short in the connected equipment or an accident that shorts something to ground--still seems less safe.

[CNYCacher]

So, what's always confused me is that installing 20amp circuits makes the breaker less likely to trip. This actually seems less safe to me. It has been explained to me that the circuit breakers are only intended to protect the installed wiring and not the end equipment nor the user. But Whenever i've had breakers trip, it has usually been some short in the connected equipment or an accident that shorts something to ground--still seems less safe.

The breaker is designed to protect the installed wiring.  Each wiring size has a maximum size breaker you can protect it with, and a minimum size of ground. Ground shorts will still trip the breaker, no matter how big it is

[geronimotwo]

Had to look this up.  Makes sense now.

although code allows it, i wouldn' say it makes sense.

[Hawkmoon]

As far as I know, code frowns on running 12 gage wire and then wiring up 15-amp receptacles, ...

Nope. The National Electric Code is perfectly happy if you over-build. The Code specifies the minimum gauge wire that can be used for the ampacity of the circuit. You can certainly use 12-gauge wire for 15-amp circuits. The Code isn't as happy if you run 14-gauge wire for a 20-amp circuit. Using 12-gauge for long runs in a 15-amp circuit is a good offset for voltage drop.

Aluminum wire is anathema. A long time ago I rented a house from my uncle. The house was built immediately after WW2, when Unk had just come back from saving the free world. Copper was still scarce, so all the wiring was aluminum. I went through the house to replace the old 2-prong outlets with grounding receptacles, and I found that ALL of them were loose and corroded. My solution was to use No-Ox on all the exposed wire ends, and then to wrap each receptacle with several turns of electrical tape.

[RoadKingLarry]

I should start a business that prints up signs for construction and remodeling sites that says,

"THIS HOUSE IS WIRED WITH ALUMINUM, AND PIPED WITH PEX AND PVC. THERE IS NO COPPER."

Maybe make some sort of pictoral representation to go with it for sub-literate crackheads/methheads. 

Either that, or we need to figure out a two-pronged approach to electrify unattended house and construction wiring and pipes to lethal levels for theft-proofing from a technology side, and making that legal from a .gov side...

We got that covered.
 

[CNYCacher]

although code allows it, i wouldn' say it makes sense.

The only reason that it makes sense is that even 15-gauge receptacles are rated for 20-amps pass-through.

And since anything which draws more than 15 amps is supposed to have the special 20-amp plug which won't fit, it's allowed.

[geronimotwo]

your counting on people having the common sense to not change the cord plug so that it will fit in 98 percent of the common outlets.

[CNYCacher]

your counting on people having the common sense to not change the cord plug so that it will fit in 98 percent of the common outlets.

I'm not.  The NEC is

I have some 20-amp circuits and they all have 20-amp receptacles.

[never_retreat]

By code you only have to put the 20 amp outlet in when it is a dedicated circuit.
So if the 20 amp breaker only feeds one outlet then it must be the 20 amp style. If not you can use the 15 amp type.
This only applies to residential.

And a kitchen requires way more than 2 circuits.
You need 2 dedicated counter top circuits.
at least 1 for floor level outlets.
something for lighting.
fridge
garbage disposal
dishwasher
microwave if it is built it.
So pretty much anything that is "installed" needs its own breaker.

[Balog]

So I'm at least passingly familiar with code or minimum number of outlets in a residential environment. Is there anything about maximum? If I want to install a double gang box where each set of receptacles is on its own dedicated circuit in each wall is there an issue with that?

[geronimotwo]

there shouldn't be more than 8 duplex outlets on any one circuit.

[Tallpine]

And a kitchen requires way more than 2 circuits.
You need 2 dedicated counter top circuits.
at least 1 for floor level outlets.
something for lighting.
fridge
garbage disposal
dishwasher
microwave if it is built it.
So pretty much anything that is "installed" needs its own breaker.

You just need to assign a number to each appliance, and then add them up and not run a combination that goes over a certain value.  Otherwise, the generator blows up 

there shouldn't be more than 8 duplex outlets on any one circuit.

Yeah, but you can plug in 8 power strips and run a lot of things 

[Scout26]

Nah, just get a few of these for each outlet.

[Hawkmoon]

your counting on people having the common sense to not change the cord plug so that it will fit in 98 percent of the common outlets.

Hehe --

Couple of weeks ago I was in the electrical aisle at Lowe's and I came across a sales drone trying to help a woman of limited English proficiency find a plug adapter. Whatever the sales drone showed the woman wasn't quite right. I speak a [very] little bit of Spanish, so I volunteered to translate. Turned out the woman had a 220-volt window air conditioner she wanted to plug into a 120-volt wall outlet. It took me awhile to explain to her that it couldn't be done because it wasn't just the plug that was different, it was the voltaje of the circuito that didn't match her machine.

The sad part is that, after explaining to the woman in Spanish, I then had to explain to the sales drone in English.

Sheesh.

[Hawkmoon]

And a kitchen requires way more than 2 circuits.
You need 2 dedicated counter top circuits.
at least 1 for floor level outlets.
something for lighting.
fridge
garbage disposal
dishwasher
microwave if it is built it.
So pretty much anything that is "installed" needs its own breaker.

This may be what some people consider good practice (I think it's a bit over the top), but it isn't required by code. The NEC requires two appliance circuits.

There is no requirement whatsoever for a floor level receptacle. I can't imagine why anyone would even want one -- kitchen floors get wet mopped -- why would I want a receptacle where I'm going to be throwing water around?

[Hawkmoon]

So I'm at least passingly familiar with code or minimum number of outlets in a residential environment. Is there anything about maximum? If I want to install a double gang box where each set of receptacles is on its own dedicated circuit in each wall is there an issue with that?

Nope. No problem.

The NEC doesn't specify any minimum number of receptacles. The requirement is that no point on a baseboard shall be more than 6 feet from a receptacle. This has nothing to do with electrical loads. It's based on the typical length of a lamp or small radio cord. The NEC wants to avoid extension cords, so that requirement is intended to ensure that anything you're likely to plug in can reach a receptacle without needing an extension cord.

Once you know how many receptacle you'll have, you can figure up how many circuits you'll need to feed them.

[zahc]

The NEC doesn't specify any minimum number of receptacles. The requirement is that no point on a baseboard shall be more than 6 feet from a receptacle.

This is an older house, and there is nowhere near that many receptacles installed in the living areas. When re-wiring a house, to what extent are you required to "bring it up to code"?

[Hawkmoon]

This is an older house, and there is nowhere near that many receptacles installed in the living areas. When re-wiring a house, to what extent are you required to "bring it up to code"?

That's a question that keeps getting debated, and although I think every state now uses some version of the International Residential Code or other (it comes out every three years and it takes some places longer than others to adopt a new edition), the way the enforcing authority interprets it isn't always uniform from one jurisdiction to the next. The general rule is that new work must conform to current code requirements, but repairs (including replacements) do not require that the entire building or structure be brought up to modern code standards.

If you only replace the actual receptacles, technically you need a building (electrical) permit, but you would not be required to bring the entire system up to today's code. Once you get into rewiring the entire house, then IMHO you cross the threshold into full code compliance territory. (And, since I am a licensed building official, albeit laid off a couple of years ago, if you were doing this in my [old] town that's what I would tell you if you were standing at the counter asking the question.

Another issue to consider IF you decide to rewire -- the original wiring will have (I hope) been stapled to the wall studs within 6 or 8 inches of each box, and then approximately 24 inches on center. You can't just disconnect the wires and pull them out of the wall, and you're not supposed to abandon them in place. Catch-22. In general, wholesale rewiring is usually undertaken only as part of a full-scale renovation, when the walls are opened up so you have access.

You can always add a couple of receptacles. Don't mis-read what I wrote:

The NEC doesn't specify any minimum number of receptacles. The requirement is that no point on a baseboard shall be more than 6 feet from a receptacle.

This does NOT say outlets 6 feet on center. It says no point farther than 6 feet from an outlet. In general, for a large wall that's 12 feet on center, not 6 feet. But any chunk of wall 24 inches wide or larger is supposed to have an outlet (because anything that wide could possible have a table and a lamp in front of it).

[zahc]

I know that it's permitted to run romex through wall spaces without fastening it to the studs if you are doing retrofits. I did NOT know that you had to remove the old wire too! That's impossible.

It looks like putting pigtails on the outlets is probably the way to go with this one.

[zxcvbob]

I know that it's permitted to run romex through wall spaces without fastening it to the studs if you are doing retrofits. I did NOT know that you had to remove the old wire too! That's impossible.

It looks like putting pigtails on the outlets is probably the way to go with this one.

afaik, only the accessible part of abandoned cable has to be removed.  I will look it up tonight (my code book is pretty old, but that will at least give you the section and paragraph numbers)

[Scout26]

Fortunately my house had conduit, so it was (fairly) easy to pull out the old CU/AL wire and then pull new CU.

[Hawkmoon]

afaik, only the accessible part of abandoned cable has to be removed.  I will look it up tonight (my code book is pretty old, but that will at least give you the section and paragraph numbers)

I believe that applies only to communications cable, and then only if there's a probability (not "possibility") that it may be used again in the future. And both ends of each run must be tagged for identification if any wires/cables are left in place.