Aluminum Electrical Wiring Hazards & Aluminum Wiring Repair Methods:
this Aluminum Wiring Website answers just about any question concerning aluminum electrical wiring, aluminum wiring failure causes, cures, repairs, and prevention. We include authoritative, expert aluminum wiring failure research, field failure reports, and descriptions of approved aluminum wiring repair procedures and products.
Photos at page top show an improper aluminum-to-copper pigtail splice which is overheating, and an infra-red photo of the same connection, from a more distant view (courtesy of G. Cohen). Aluminum wire connections can overheat enough to start a fire without ever drawing enough current to trip a circuit breaker.
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How safe is aluminum wiring? According to the U.S. Consumer Product Safety Commission, fires and even deaths have been reported to have been caused by this hazard.
due to aluminum wiring expansion, or much more likely micro-fretting and arcing at the aluminum wiring connectors,
can cause overheating at connections between the wire and
devices (switches and outlets) or at aluminum wire splices.
The connections can become hot enough
to start a fire without ever tripping a circuit breaker!
The photos shown at left and just below are not the most dramatic catastrophes linked to fires caused by aluminum wiring. But these are conditions that are found in many homes with aluminum wiring, confirming that this is a real, common, and widespread hazard.
CPSC research shows that "homes wired with aluminum wire manufactured before 1972 are 55 times more likely to have one or more connections reach "FireHazard Conditions" than are homes wired with copper.
"Post 1972" aluminum wire is also a concern. Introduction of the aluminum wire "alloys" in 1972 time frame did not solve most of the connection failure problems.
Aluminum wiring is still permitted and used for certain applications, including residential service entrance wiring and single-purpose higher amperage circuits such as 240V air conditioning or electric range circuits.
The fire risk from single purpose circuits is much less than for branch circuits.
But it's not necessarily because of a "new alloy" as some folks assert. It's because there are enormously fewer connections (four or six rather than 30 or 40 per circuit) and thus statistically a smaller chance of a connection failure. These connections do still burn up, as indicated by field reports.
ALUMINUM WIRING HAZARDS & REPAIRS The Aluminum Wiring Website, describing the hazards of & repairs for aluminum electrical wiring, including authoritative, in-depth information, photographs, documents. You are on the aluminum wiring website main page.
Suggested citation for this web page
The AMP (originally TYCO) COPALUM connector method is described is described in detail at PIGTAILING USING AMP "COPALUM" CONNECTORS.
COPALUM ALUMINUM WIRING CONNECTOR AVAILABILITY discusses how to get these aluminum wire connectors
The AlumiConn connector is now recommended for aluminum wiring repairs - US CPSC.
Results of independent testing indicate that this product "... is predicted to have a high probability of failure-free long-term safe performance, PROVIDED THAT THE SETSCREWS ARE CAREFULLY TIGHTENED TO THE MANUFACTURER'S RECOMMENDATION".
Alumi-Conn where to buy, how to install:
Scotchlok 3M Special Method [- superceded by new alternate repair as of June 2007 -]: this ""Scotchlok 3M Special Method was previously recommended as independent tests showed that it performed acceptably.
While this repair method has been superceded by new alternate repair as of June 2007, we have kept this description available to aid home buyers, electricians and home inspectors who may discover or need to be able to recognize this aluminum wire repair method if it was previously used in the building.
A summary of this method is at "Scotchlok 3M connector" and details of this method are at Aluminum Wire alternative repair: Special Aluminum Wire Repair Method
Other Aluminum Wiring Repair Methods that Are Not Recommended
Other methods - not recommended: Warnings regarding other "repair" methods which are not recommended are discussed at ALUMINUM WIRING REPAIR, Other Products, such as the Ideal 65 purple "Twister" connector shown in the photo at left (12 connectors cost $49. to $79.), Marrette B-Cap ACS™ #63 AL/CU Twist-On Connectors, and electrical receptacles and outlets marked "COALR" (even if these worked, which has not been demonstrated, what about all of the other electrical connections and splices in the building?) and others.
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Continue reading at ALUMINUM WIRING IDENTIFICATION or select a topic from the More Reading links shown below.
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Green link shows where you are in this article series.
The link just above provides access to Reducing the Fire Hazards in Aluminum-Wired Homes, by Dr. Jess Aronstein, Ph.D., This document answers most technical questions about the hazards and remedies of aluminum electrical wiring. An easy to print form of this guide in PDF form is also provided free at ALUMINUM-WIRED HOMES, REDUCE THE HAZARD [PDF].
Frequently Asked Questions (FAQs)
Question: Can Aluminum House Wiring Cause or Contribute to Appliance Failures?
I read your 5/21/07-updated report on Reducing the Fire Hazards in Aluminum-Wired Homes I can't tell you how grateful I am to you for making this info readily available to the (semi) average consumer in such an unbiased fashion. We bought an aluminum-wired home 10 years ago and didn't give it an incredible amount of thought at the time. We also weren't planning to ever have children, but now that we have a three-year-old child, our choices and priorities are different than they were when it was just us!
We seem to be having an unusual number of electrical appliance failures
I have re-visited this issue for another reason (and in so doing, realized that we did not take it seriously enough for our current family situation). We have had a seemingly (to me) inordinate amount of appliances fail, particularly in the last few (say, 3-5) years.
This year alone, we've had a dryer (the second), a fridge (the second), a microwave (the second or third), our very large, very expensive TV (the second problem, the first fixed under extended warranty about 5 years ago) and some other suspicious appliances "stop" working.
Granted, quality isn't what it used to be, and both dryers were old (the second one was VERY old, like 25+ given to us as a replacement for the first), but both fridges were relatively young (one 5, very expensive, one 3 or less, a moderate replacement), one microwave was newer (less than 2 and large and expensive convection/bake model, given as a gift to replace our old one), and our TV is about 10 years old.
I think there's something going on with our built-in electric cooktop, too. We've also had a couple of computers that required replacement of the power supply (two different models, both not terribly old), which I know can be even less-relatable.
This makes me wonder if somehow our electrical system itself or the presence of Aluminum wiring is connected with these failures?
All of this makes me wonder if somehow our Aluminum wiring is connected with these failures? I think there may have been one or two smaller appliances, too, that I'm forgetting?
I haven't really found anything on [the role of electrical wiring in appliance failures] online - only the stuff relating to electrical fires. My husband, who is not licensed, but as a maintenance technician at a large plant for many years, has a fair amount of knowledge about electrical work also says he can't see how the aluminum wiring could cause these things to go bad (and it logically seemed correct, the way he explained it to me), but he also admits "anything is possible". I know it's anecdotal, but no one else I know of has had the kind of "bad karma" we've had with appliances of all kinds.
I'm sure you field all kinds of wacko questions, and I realize this might be something you simply can't answer based on what I've told you, but I appreciate any time and effort you might be able to give in response. - Wendy Moses
Reply: Electrical appliance failures may in fact be related to the electrical system and its connections
Your questions are good. The electrical appliance failures may in fact be related to the electrical system and its connections.
There are two ways that these failures can occur from problems in the electrical system.
First, there may be one or more high resistance or open connections in the neutral and/or ground leg of the electrical service. It may be at the power company's pole transformer, in your circuit breaker panel, or somewhere in-between. A high resistance or open connection in the neutral leg of the electrical service causes low voltage on heavy loads on one side (normally 120volt) of the split 240V system and high voltage on the other side (also normally 120volt).
This can cause early failure of motors, which tend to overheat on low voltage, or electronics and lamps, which are sensitive to over voltage. This can be checked for by loading one side of the system and checking voltage on both sides. If there is only a small change in the voltage balance when one side is heavily loaded, then the neutral leg is probably OK. If there is a substantial change, then you have one or more high resistance connections in the neutral leg of the system.
Second, high resistance connections in the branch circuits can also be the cause, for similar reasons. Even in some 240volt circuits there are unbalanced loads. For instance, the dryer motors typically run on 120volts even though the appliance is nominally 240volts.
Keep in mind that abnormalities in the electrical system may pose a fire hazard in addition to the equipment reliability problem. For safety reasons, your system should be checked as soon as possible. - Jesse Aronstein, Ph.D., P.E., (845) 462-6452
Why does my home have a mix of copper and aluminum electrical wire?
Question: Why is only some wiring aluminum? I am dreading the repair cost.
A recent 4 point inspection of our home revealed aluminum wiring at 3 points ( for want of a better description ) in our circuit breaker. Why would only some of the wiring being aluminum? One of the areas was the "larger" wire. Is this a very costly repair? Thank you for your time and attention and expert information as I have no idea and am dreading what the cost might be to rectify this problem. - K.S.
Reply: Reasons for finding mixed copper/aluminum electrical wiring in a home; range of aluminum wiring repair costs
Comment: Correct Part Number for Ordering the AlumiConn aluminum wire repair connector - where to order
Our company is the manufacturer of the AlumiConn. We have noticed on your site that you are providing item number 95103, this item number is a sample bag and is creating confusion when the consumer goes to a distributor. Can the item number be changed to 95135?.
Customer Relations Coordinator,
When reading the article we noticed it stated the Alcop Store was our company sales website. They are actually an independent distributor. I also saw that the link to the AlumiConn Site was directed to the Alcop Store as well. The actual AlumiConn Site is http://www.kinginnovation.com/products/alumiconn/ This site has installation videos, Wire combinations, specification sheets, and much more.
Thanks so much Jennifer, we have posted the corrected part or item number for the AlumiConn connector.
Question: detection of evidence of a proper or improper repair of alumium electrical wiring
I recently received the attached home inspection report and im wondering if you could take a quick look at it and tell me a bit of info. Im trying to determine if the aluminum wiring has been pigtailed according to the info on the page. I am curious to know if you can tell by reading this if the aluminum non-metallic sheathed wiring means the wires have been “pigtailed”? does sheathed mean pigtailed? - Anon., Insurance Agent, British Columbia
A competent onsite inspection by an expert usually finds additional clues that would permit a more accurate, complete, and authoritative answer than we can give by email alone. For example, though there is nothing in the report you attached that indicated that ANY repair had been made to the aluminum wiring, that observation is inconclusive - which leaves one disappointed in the value of the report or the thoroughness of its writer. Here are some things to keep in mind and that in my opinion are quite reliable:
Anon: the report you attached says that the inspector observed both non-metallic sheathed copper wiring and non-metallic sheathed aluminum wiring. The report states "There are 7 aluminum circuits including stove and dryer circuits" found in a 14-circuit 100A 240V electrical panel.
In this "lingo" "sheathed" refers to the insulating jacket of the wiring, not to connectors or repair devices. "Non-metallic sheathed ... wiring" means that the wire is insulated or that its external jacket is plastic or fabric or a similar non-metallic product. It has nothing to do with repairs or connectors.
Now if the only aluminum wire circuits were multi-strand high amp circuits supplying an electric stove and clothes dryer, while failures indeed still occur on such circuits, in part because the number of electrical connections in the circuit are very few (just two or three at each end of a normal stove or dryer circuit), and because multistranded wire is used, general practice is to leave such circuits in place and alone unless there is evidence of a need for repair such as corrosion or signs of overheating or loosening.
As you know, that is not the case for solid conductor aluminum branch circuit wiring, where typically there are many connections and for other reasons too, a higher probability of failure, overheating, and fire.
IF we spot solid conductor branch circuit aluminum wiring in the electrical panel and no repair has been done there - where the wires and circuits are normally quite visible, then you can safely conclude that no proper aluminum wiring repair has been done on the building. That's because no knowledgable professional would go into the building and touch just some of the alumium wired devices and circuits but leave others unattended - doing so would be to invite liability and blame should a future wiring-related fire occur.<
Second, even if we do spot a repair effort in the electrical panel, you would want to know that it was done properly - at least that a US CPSC-recommended approach was used (either the AMP-TYCO crimp type connector, or the King Innovations approved terminal block repair connector). Other repair efforts such as by using twist-on connectors are not recommended and in fact may actually increase the hazard.
Third, it is fair to agree that the home inspector or mortgage company inspector is not, unless prearranged, going to make an exhaustive inspection of all of the wired devices (receptacles, switches, junction boxes) in the building - which is why the inspection and report of observations at the electrical panel is both critical and very informative.
Finally, since the inspector says there are 7 circuits and accounts for only two as high-amp (stove and dryer) it is reasonable to conclude that there are at least 5 solid conductor aluminum wired electrical circuits that need attention in the home.
Watch out: do not call for a repair but permit an unaccepted repair method or the electrical hazard may go from bad to worse.
Question: insurance companies' position on aluminum wiring
(June 17, 2014) Bob said:
Are there insurance companies that will insure a large building(91 units) with aluminum wiring?
My OPINION is that you may find some insurance companies that don't ask about the wiring type and that will issue a fire policy. But WATCH OUT: you may find that should a loss occur that is blamed on the aluminum wiring you may find that coverage is not going to be provided.
Be sure to discuss the wiring and your concern with your insurance company - otherwise the coverage is a mere false sense of security.
For sure, some insurance companies will not insure an aluminum-wired building until the wiring has been properly repaired using an approved US CPSC Method.
(July 14, 2014) Anonymous said: OPINION
I have worked for three different insurance companies and the short answer is yes. In insurance you have two different markets, the standard market where 95% of people get insurance and the excess market where the other 5% get insurance. You would need to goto a suplus or excess market to get coverage.
Excess or surplus insurance companies have rates that are not restricted and because they often have no competition from other insurance companies they can charge a lot more. Typically they are 3 to 5 times more expensive than a standard market insurance policy. You may be able to get a policy in the standard market but this would be a hazardous fact that you concealed from the insurance carrier and you would be denied coverage in the event of the claim.
Most companies always ask this question but either due to time constraints, the massive amount of work some insurance companies place on their employees, or human error there are people who are able to "sneak" by and get a policy in the standard market. In the event of a claim they will regret doing this as they will have been paying for insurance and not have the claim covered.
The best and only option you and everyone else who has a building with aluminum wiring have is to pay to have all the aluminum wiring replaced. The copalum method was deemed safe but only if you get every spliced connection and since you can never truly know that you got every splice or connection you should do the right thing and pay the high up front cost to have it all replaced. It will save you a fortune in future insurance cost and potentially save someones life down the road. There are times in life where it is okay to cut corners but this is not one of them. The copalum method is a joke if you ask me and I hate they even mention it as being safe. With peoples lives on the line you don't cut corners.
You are right that failure to repair every aluminum wire connection using a US CPSC-recommended connector such as the COPALUM crimp connector or the King Innovations AlumiConn leaves risk and worse, in my OPINION, may actually increase the risk of a catastrophe since occupants whose home was improperly or incompletely repaired now may ignore dangerous warning signs and thus suffer a fire or loss.
You are a bit harsh and mistaken to call the COPALUM method a joke. Perhaps you've not found time to read the research nor study the connector and its performance. That device actually makes a very effective cold weld between the aluminum and copper wires to form a safe connection. A more legitimate problem with any pigtail repair vs. re-wire repair is the limitation of adequate working space inside the junction boxes. - Editor
Question: legal options when discovering aluminum wiring after buying a home
(Sept 9, 2014) MaryR said:
I recently purchased what I was told was a 1977 mobile home. It took the owners more than 3 months to get the title to at which time I found it to be a 1971.
Now I find that it also has Aluminum wiring, which was not disclosed. My electric bills are off the charts at $4 to 500 per month. I have tried to contact the owner (lives out of state) to no avail. Do I have any legal options here? It was a cash sale that the manager of the park took care of so I never got to speak to the actual owner and now that I have this new information, no one seems to be talking. There is nothing in writing in regards to the sale, just cash exchanging hands.
The legal options are a question for you to take to your attorney, starting with the lawyer who helped you with the contracts for purchase of the home as s/he is likely to be familiar with local real estate laws.
In my OPINION (I'm not a lawyer) real estate sales are very much a "caveat emptor" or buyer beware deal. Only if you can show fraudulent misrepresentation might you have a wire to hang a case upon.
Separate from legal recourse, be SURE to read with care the aluminum wire fire hazard and safety recommendations in this article series; if you ignore danger signs or overheat a connector the legal question may become moot as you could have a life-threatening fire.
(Sept 23, 2014) Mary said:
Thanks for helping. Any and all information at this point is wonderful. There was no attorney involvement in the home transaction. The home sits in an already established community where I pay only the lot rent. When I purchased it the owners were up north and had the park manager doing the sale. It was a cash sale. I had two friends with me and a list of questions which included roof leaks, floors any and all known problems etc. I asked what the average electric bill was and was told around $50 to $60. Its been over $400 since I have been there.
I have roof leaks (was told the roof was new). The air conditioner does not work. The hot water heater quit in 2 days and then the neighbors began telling me the previous owners constantly had electrical issues. These things the park manager denies. I still have not spoken to the previous owners as the park manager said he was in charge of the sale. I expected to have things happen. Hot water heater etc in an older home, but I did not expect to be lied to about such a life threatening problem.
I can see were some of the outlets have been pigtailed, but I have no idea if its right or wrong. Or what was done at the box etc. In the lot rental agreement it states we have to have our homes insured. No one will insure mine so surely the previous owners were unable to insure it also. I appreciate your help and any information you might have to help guide me. It took the park manager from Feb (purchase) till last month (august) to get the title to me so I was still believing I had a 1977 and didn't see the dangers. I will call an attorney, but right now it looking like I might just sell the thing and move on. I have grandchildren and cant risk it. Thanks so much
I suspect that your attorney will tell you that the sale of a home with known hazards may not only put the future occupants at risk, but may be a liability for the seller unless fully adequate disclosure is made at the time of sale.
Question: aluminum electrical wiring in India
(Oct 6, 2014) Deepak Gidwani said:
Is aluminium wiring banned in India? When did that happen, which year? Pls let me know the correct legal position on this matter. Tks and rgds.
Good question, I don't know. My search could not find references to a ban on aluminum wiring in India.
There is Indian research on aluminum electrical systems and components, whose authors can probably give you more detail. See especially the first two of these articles
Beniwal, N. S., D. K. Dwivedi, and H. O. Gupta. "Creep Failure and Prevention in Aluminum Wound Distribution Transformers." Journal of failure analysis and prevention 11, no. 5 (2011): 530-538.
Ramakrishnan, K. Mathangi, M. Babu, B. Ramachandran Mathivanan, S. Balasubramanian, and K. Raghuram. "High voltage electrical burn injuries in teenage children: Case studies with similarities (an Indian perspective)." Annals of burns and fire disasters 26, no. 3 (2013): 121.
Nath, Devender. "Indian experience with aluminum busbars, links, and cable terminations for use on low-voltage systems up to 1000 V." Components, Hybrids, and Manufacturing Technology, IEEE Transactions on 9, no. 1 (1986): 30-34.
Chowdhury, Kanchan. "Fires in Indian hospitals: root cause analysis and recommendations for their prevention." Journal of clinical anesthesia (2014).
Davis, Joseph R. Aluminum and aluminum alloys. Edited by Joseph R. Davis. ASM international, 1993.
Watch out for self-serving presentations.
Agrawal, Er Naresh Chandra, and Ashish Agarwal. "E-WASTE BY ELECTRICAL WIRES–IMPLEMENTATION OF GREEN SUPPLY CHAIN MANAGEGMENT."
Mak, Alex, and P. Eng. "Successfully Countering Theft Of Copper Street-Lighting Cable."
Question: aluminum wired hot tub blows controller
11/13/2014 Ed said:
Hi, we have aluminum wiring for our hot tub. We have replaced 2 different packs (computer units that run the hot tub) in the last 2 years. We now have a third one from a different company. It is now giving us problems. The fuses keep blowing. The hot tub people are telling us that the amperage lowers when the hot tub is under a big load (both blower running, heater and lights) We have aluminum wiring from the house to the breaker and copper wiring from the breaker to the hot tub. Trying to figure out if we need to have something re-wired.
I'd replace the aluminum circuit with copper and be sure to use adequately-sized copper wire to avoid any unacceptable voltage drop in the circuit.
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