Purchased a new home il Louisiana in 2006 (newly built on purchased lot) and now discovered that the 220v. lines have aluminum wiring. Called the permit section of the local government and they act as if it's o.k. to have aluminum wiring in a residential setting. Is this permitted anywhere in the country for 220v. circuits (i.e. electric range, a.c., water heater)?

[Brian E. Kelly]

Yes it is fine. Often times the 220 volt circuits are wired with stranded Aluminum wire. Not a problem.

[Michael Roberson]

The above post is true, I would like to clarify that Aluminum is a fine conductor of electricity, however requires 1-2 gauges thicker than copper to conduct the same electricity. Its only slightly more resistant than copper, which creates slightly more heat, and hence more mass is needed.

I hope this was helpful.

[Billy Boerner]

Question:
How typical is aluminium wiring to the circuit box and for all 220 volt appliances in homes and apartments? Is it considered fairly standard?

- John from Kansas City, MO


Answer:
Hello John,

The use of braided aluminum lines for 220 Voltage lines and for transmission lines is very common and not a problem. As used in electrical panels, these wires should be coated at the point of connection with an anti-oxidant jell.

It is quite common to see the use of braided aluminum wires at the main wires coming into the panel, and the circuits for electric stoves, electric furnaces and other large 220 Volt equipment. In such applications it is quite unusual to see copper wires.

The problems with aluminum wires are with single strand 110 Volt wires and 220 Volt circuits. Such wiring was used for a relatively short period of time, should be corrected and is no longer is use.

George

[Ian A. Niquette]

Who is George, Billy?

[Paul W. Abernathy]

Bill,

Where does it say on Service Panels that AL Service Conductors require Anti-Oxident Paste? Is it a prudent choice or simply a suggestion?

[Billy Boerner]

Probably simply a suggestion... read below.


Rehabbing a Home That Has Aluminum Wiring
Rehabbing a home built between 1965 - 1973? Chances are the house has aluminum wiring. If so, you need to know how to deal with this situation so your costs are covered and make sure the home is safe since working with aluminum wiring has to be treated differently than with copper wiring.

Why did they start using aluminum in the first place?

Aluminum wiring was installed in most of the homes built between 1965 - 1973 because the high use of copper by the military during the Vietnam War. This made obtaining copper wire difficult and expensive. The alternative was aluminum wiring which was plentiful and cheap, but the potential danger it posed was not recognized at the time.

What makes aluminum wiring more dangerous that copper?

Aluminum by nature is a softer metal that copper, it contracts and expands more when heated and is more susceptible to oxidation, which is a thin film on it's surface caused by oxygen. It should be noted that this pertains to only to the smaller single wires that you see on wall receptacles and switches. The aluminum stranded wiring you see on the 220 volt appliance and air conditioning circuits do not pose a problem. When aluminum wires are only twisted together, like you would with copper, the wires expand and contract then current flows through them which produces heat from the poor connection and if the wires has oxidized, this will heat up the connection even further, causing a potential for overheating and a possible fire.

How can I tell if the house has aluminum wiring?

The best way to know is to have it verified by an electrician or home inspector. You can check yourself but of course, you need to be careful. I do not suggest that you remove the breaker panel cover which will show all the wiring from the circuits, but you could turn the breaker off to a room and remove the cover plates to the light switches and receptacles and loosen the screws that hold them in the electrical box. Pull the switch or receptacle out and look at the bare wire around the connection screw. Aluminum will be bright silver. This is not to be confused with tinned copper wiring which has a dull silver finish, but this was used in a much earlier time.

What special precautions need to be taken when working with aluminum wiring?

My best advice is to have all the wiring evaluated by a licensed electrician for safety, preferable one that is familiar with aluminum and if you can keep from changing out receptacles, switches and lighting that would be best, just don't mess with it. I know if you are doing a complete rehab, you will want to change out lights, old and dirty light switches and receptacles with many coats of paint, but if you can clean them up, you are better off.

Other options are:

1. Rewire the house with copper wiring. This is not much of a choice since a typical house could cost ten thousand dollars or more.

2. You can connect copper to a typical outlet or switch and attached to it to the aluminum wire in the wall. You would need to hire an electrician to make the connections using the approved method called Copalum, which utilized a special connector and a high pressure crimping tool to make the connection. This would be very expensive if you even could find an electrician that still has the equipment. I have heard of around $10.00 - $15.00 per connection.

3. Change out switches and receptacles with special aluminum rated ones. You can get them at electrical supply companies, online or I have found them at Lowes. The problem is they are more expensive. You will pay about fifty cents for a normal copper rated wall outlet, but an aluminum rated one will cost about $3.75 and a wall switch is about $4.50. Needless to say, this will add up costs to your bottom line, but still cheaper.

4. There is a connector sold that has had good testing results named Alumiconn. These are still about $3.00, so you might as well spend another dollar and buy the aluminum rated outlet or switch. I would use these for connecting light fixtures or other connections.

The other precaution to take is to use an anti-oxidant paste on all connections. This is a thick grey paste that keeps the wire from oxidation and help prevent resistive heat.

The important thing to remember when working with aluminum wiring is that it is not the wiring itself that is makes it dangerous, it is the wiring connections. I am reminded of last year when I inspected a home that was featured on the TV show "Flip this House" and the guys that did the rehab, did their own wiring and just used a normal twist connectors to join wires together. A licensed electrician had to be called in to rewire the entire home and the price of the home had to be lowered to allow for these repairs. They didn't want to spend the extra money on the proper outlets and switches and it wound up costing them more in the long run. You want to put out a quality and safe home and not put others at risk, so please be careful when dealing with homes with aluminum wiring.

Kent Keith is a professional real estate inspector in Fort Worth Texas and serves the entire Dallas / Fort Worth areas. He is also a certified whole house diagnostic energy inspector performing home energy audits as well. You can get great information on houses and home inspections by going to his website at: http://www.fortworthinspector.com

[Paul W. Abernathy]

Ahh.....I wont read all that but I will say this. If person has a new panel and it does not have Anti-Oxident on the AL Conductors on the main lugs and an HI calls it a defect in his report, I sure hope they have some verbiage on the panel cover that supports their claims. Not just an opinion from a 3rd party source.

[David P. Valley]

[QUOTE=pabernathy;542796]Ahh.....I wont read all that but I will say this. If person has a new panel and it does not have Anti-Oxident on the AL Conductors on the main lugs and an HI calls it a defect in his report, I sure hope they have some verbiage on the panel cover that supports their claims. Not just an opinion from a 3rd party source.[/QUOTE]



You are absolutely correct. Some stranded aluminum wiring does not need the antioxidant.

[Joe Funderburk, CMI]

I often see solid core aluminum (size 8) going to the water heater.

Anyone have heartache about that? If you have a problem with it, what would you say about it?

[Brian E. Kelly]

[QUOTE=jfunderburk;542936]I often see solid core aluminum (size 8) going to the water heater.

Anyone have heartache about that? If you have a problem with it, what would you say about it?[/QUOTE]


Joe, I point out any solid AL conductors. They shoud be periodicly checked/tightened by an Electrician as far as I know.

[Jeffrey R. Jonas]

[QUOTE=bkelly2;543045]Joe, I point out any solid AL conductors. They shoud be periodicly checked/tightened by an Electrician as far as I know.[/QUOTE]


Joe,
I do the same as BK. I report all solid core AL on the premises, irrelevant of what it serves.
Jeff

[Keith Runquist]

Solid aluminum is not good. Wright it up. I have to say though I've never seen it here ever. Must be a regional thing.

[Paul W. Abernathy]

Exactly how many home fires have you seen caused by the AL Wiring or is it the AL Wiring to Poor Terminations?.

You are all aware that nothing in the NEC prohibits 12,10 or 8 AWG AL Solid just because it is Solid AL....their are other factors involved.

(B) Conductor Material. Conductors in this article shall
be of aluminum, copper-clad aluminum, or copper unless
otherwise specified.

310.3 Stranded Conductors. Where installed in raceways,
conductors of size 8 AWG and larger shall be stranded.
Exception: As permitted or required elsewhere in this
Code.

or how about this.....

310.14 Aluminum Conductor Material. Solid aluminum
conductors 8, 10, and 12 AWG shall be made of an AA-
8000 series electrical grade aluminum alloy conductor material.
Stranded aluminum conductors 8 AWG through 1000
kcmil marked as Type RHH, RHW, XHHW, THW, THHW,
THWN, THHN, service-entrance Type SE Style U and SE
Style R shall be made of an AA-8000 series electrical grade
aluminum alloy conductor material.


My point is this......if you call out all solid AL wiring, be sure you know when it is OK for the solid AL wiring. Chances are the older AL Wiring from the early 70's would not comply with the AA-8000 series portion of the requirements...just more useless information to remember.

[Jeffrey Moore]

Paul,

How would you know if it is AA-8000 series electrical grade aluminum alloy conductor material or something else?