Any electricians? single strand alluminum wiring.

[SingleStack]

Hey guys. How dangerous is single strand alluminum wiring in houses? And are there any safe and effective fixes other than a complete rewiring job?

We have heard mixed things about pigtailing, are there any other methods?

[Will Carry]

That dates your home pretty well. They only used aluminum wiring for a few years back in the 70s (I think). I live in a community of close to 1000 homes that were all built with aluminum wiring. None of these homes has burned because of the aluminum wiring.  My home has aluminum wiring.  I have no intentions of rewiring my home. They do make a flux paste that you can put inside of wire nuts when you are connecting aluminum wire to copper wire. I always use this when replacing light fixtures. Your oven and clothes drier circuit is probably all copper wiring. I was an electrician and have a degrees in Electrical Engineering Technology and Electronics Technology.

Edited March 23, 2014 by Will Carry

[NashvilleStage]

Could you post a few pictures? It'll mostly depend on the condition of the insulation.

 

Aluminum wire in-and-of-itself is fine, and is still used today for larger size wiring because of its lower cost. There are basically three tradeoffs: Aluminum isn't quite as good of a conductor as copper, so you have to use a larger size wire for a given amount of current. Also, the surface will oxidize some over time, which will create an area of higher resistance (and thus higher temperature, possibly leading to a fire if it gets hot enough) where there is a connection to something else (wire nut, clamp, outlet, etc.). This is usually prevented by covering a freshly-stripped piece of wire with an anti-oxidizing paste. Lastly, all of the connectors have to be rated for use with aluminum because of the dissimilar metals. Most modern connectors & wire nuts are, and will be stamped as "AL/CU" somewhere on them.

 

What are you wanting to do?

[SingleStack]

Thanks for the replys.  We are looking at buying a house and it has single strand alluminum wiring. The home inspector told us about the wiring and possible dangers.

He told us about pigtailing , using the special wire nut with nonoxidizing paste.  Being first time home buyers we realy have no idea whats the norm.

 

Could you post a few pictures? It'll mostly depend on the condition of the insulation.

 

Aluminum wire in-and-of-itself is fine, and is still used today for larger size wiring because of its lower cost. There are basically three tradeoffs: Aluminum isn't quite as good of a conductor as copper, so you have to use a larger size wire for a given amount of current. Also, the surface will oxidize some over time, which will create an area of higher resistance (and thus higher temperature, possibly leading to a fire if it gets hot enough) where there is a connection to something else (wire nut, clamp, outlet, etc.). This is usually prevented by covering a freshly-stripped piece of wire with an anti-oxidizing paste. Lastly, all of the connectors have to be rated for use with aluminum because of the dissimilar metals. Most modern connectors & wire nuts are, and will be stamped as "AL/CU" somewhere on them.

 

What are you wanting to do?

I dont have any pics.  But  right now the connections to the terminals are unsafe according to the home inspector.

If a qualified electrician made the connections, would you feel safe with the wiring?

[vontar]

My home has aluminum wiring as well.  As I am able to afford it I plan to start changing out some of the circuits 1 by 1.  I know that is going to be expensive though.

[NashvilleStage]

I'd recommend that you pass on it. It would be OK if you were comfortable with doing electrical work, and enjoyed doing renovation type projects yourself. It's probably more hassle than you want to deal with as first-time homeowners, and paying someone else to work on it gets expensive quickly.

 

From what I've read, there haven't been a ton of house fires from aluminum wiring, but the connections can be finicky, and they degrade more with age compared  to copper. Being that it's a house that you haven't lived in & don't know the history, you'd probably want to inspect and/or re-do every connection in the house (every switch, every outlet, every ceiling light, and the whole breaker panel or fuse box).

 

Either way, it definitely reduces the value of the house in the amount that it would take a contractor to do all of the work. Think of it the same as any other system in the house that is antiquated or in disrepair & needs fixing. Figure the cost of repairs against the price of the house. If you negotiate a great deal (value of the house, minus repairs, minus some extra for the trouble), then you're good to go.

 

I'm guessing that's not the case with your situation, though.

[OH UNCLE PAUL]

These are designed for cu/al connections.

http://t.homedepot.com/p/Ideal-Twister-Al-Cu-Wire-Connectors-65-Purple-10-per-Package-30-1765S/202935623

[nightrunner]

As an electrician, i loathe aluminum wiring. It is cheaper but not worth it. I refuse to work with it unless i can make connections with screw in lugs, mainly very large service wire.

I would equate it to cast iron plumbing. It will be ok for now, but definitely needs replacing as soon as you can.

[Guest theconstitutionrocks]

I am uber paranoid when it comes to electricity. While I DO run my own circuits (finished out the basement), I always go up 1, usually 2 gauges, on wire thicknesses relative to the amount of amperage my circuit breaker is rated for. Everything except the SEC cables and panel ground in my house is copper (course it was built in 96).

[Randall53]

I've got 40 years experience as an electrician. I would NEVER buy a house with aluminum wire. Even in the service entrance cables. It's not even legal anymore. Your insurance company will really be unhappy. Edited March 24, 2014 by Randall53

[leroy]

I'll join the chorus of "Anti-aluminum wire" proponents...  I'm an amateur electrician and have been around this stuff my whole working career in industrial settings... Aluminum wiring is ok in outside industrial settings for high voltage applications... Copper wire is the wire of choice for distribution and low voltage settings for a reason....It's safe, forgiving of "clumsy installation", and long lasting...

 

The problem i see with using aluminum in residential wiring is that residential wiring is not run in rigid conduit (...industrial installations are...), aluminum wiring is flammable (...copper is not...), there is a very disconcerting history of residential fires directly attributed to poor connections in aluminum wiring.... This fact, alone, should trouble you.... There are hundreds of these connections in your house, from switch leads, light distribution boxes, plugs,  and in the breaker panel...  I would never take the chance of using aluminum wiring in any of these locations... It takes only one bad connection (...or loose connection...) to generate enough resistance to heat up a junction box enough to flame... Cooper wont do that; aluminum will...

 

I've seen some connections that got very hot from loosening from poor installation (...mostly not taking the time to re-tighten the connection lugs after putting the circuit in service...) and overloading in service (...think contractors in heavy load connections like air condition and heating elements here....), that charred but didn't burn... They were all connected with copper wiring... I simply dont think that aluminum wire would be safe in any application that is not perfectly installed (...which is rare...) or adequately rated (...another rarity...)... I simply wouldn't take the chance... You are gambling with both your safety and most likely the biggest investment you will ever make.... I simply dont like the odds... More than that; there are several houses from the era of aluminum wiring installation that have burned in my area...

 

leroy

[peejman]

What they said... pass or have it replaced as condition of the sale. 

Edited March 24, 2014 by peejman

[NashvilleStage]

It's not even legal anymore.

 

Well, not to be nit-picky, but the National Electric Code does not forbid aluminum wire. It's possible that your local Authority Having Jurisdiction is more strict than the national codes, though.

 

For example, NEC Table 310.16 http://www.houwire.com/products/technical/article310_16.html lists the maximum current flow for a given wire size, based on the temperature rating of the insulation and the wire material (either copper or aluminum / copper-clad aluminum).

[SingleStack]

Wow thanks guys. i called a few electricians for quotes for pigtailing and they said they wont do those types of connections.

I think we will be looking at some more houses

[MacGyver]

I'll echo others.  If you're not already in, stay out it.

 

Having it replaced as a condition of sale might be an option, but I'm guessing it would be expensive enough as to cause the seller to back out.