Al/Cu splicing

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2/5/2016 at 1:26:08 PM

My grandaughter's house has original aluminum wiring from the supply panel. A previous owner replaced the duplex receptacles using copper devices.where the Al/Cu splice was made using regular wire connectors filled with No-Oxid grease.

Do you advise replacing the receptacles with Al compliant devices, or can the "Ideal #65 Twister Al/Cu connector be used and still meet code.

I would also like an approximate cost estimate for each method assuming 28 receptacles,15 switches, 6 light fixtures and7 ceiling fans.

What precautions must be taken when dealing with Aluminum wiring?

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Robert from Electrilight Ltd. in Oakville
Date/Time2/5/2016 at 3:43:22 PM

Copper marrettes (wire nuts) are not allowed on aluminum wiring, regardless of the paste used. Marrette Brand #63 and #65 are approved or an Ideal brand. Working with aluminum must be done in a very particular manner and I have even seen Journeymen fail to make these connections properly. Copper to aluminum can overheat if not done properly and make the connections worse.

Best to call and hire a Licensed Electrical Contractor in your area and ask them if specialize in aluminum repairs.

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Date/Time2/5/2016 at 3:57:18 PM

Hugh, thank you for posting this very important question. Knowing how to deal with Aluminum wiring is a question that many homeowners pose, and this topic will be revisited for years to come.

What you describe is something I see often: Incompatible devices wired to Aluminum, or Copper wire nuts on Aluminum splices, or the correct wire nuts but without the Aluminum Oxide. What's the big deal really?

The big deal is that when it comes to protecting your property and your loved ones, the greatest chance for safety comes by assessing and treating Aluminum thoroughly, and by not skipping any of the important steps. A licensed technician who has experience treating Aluminum will know this.

An experienced technician will assess not only your outlets but every switch and every light fixture (they too require wire nuts). Essentially your whole home gets examined and if there is any sign of arcing or burning, he/she will discover this and correct it. In your case, an incorrect wire nut is used. You have reason to be concerned.

Typically, treating Aluminum wiring is not for the common homeowner; it's best to get a technician in to assess and then make recommendations. Once he/she has a handle of the scope of work involved they will then be able to provide you with an accurate cost for the work.

All the best.

Henry Kirsch

Kirsch Electric Contracting Inc

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Dave from Nemco in Cambridge
Date/Time2/5/2016 at 7:42:47 PM

Copper oxide paste is used when stranded aluminum wire is tightened into a screw connector. Aluminum rated marretts are required when connecting copper to a aluminum, paste is not required when using these approved marretts. Special care must be taken to ensure a proper secure connection, it's not to be done by a non professional. Too many things can go wrong, it could take years for a bad connection to rear it's ugly head and cause a fire.Typically we charge $25 per device to inspect and install new devices throughout the home. All ceiling and junction boxes need to be inspected for wear/bad connections. Aluminum wiring requires maintenance and I wouldn't recommend installing aluminum devices since the installation method is usually at fault in the first place. Pig tailing each outlet is my preferred method. That way the outlet will only handle the appliance that's plugged in to it rather than the combined wattage of the whole circuit.



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Robert from Electrilight Ltd. in Oakville
Date/Time2/5/2016 at 8:56:40 PM

Sorry Dave, I have to disagree with you that paste is not required for a copper to aluminum connection. Aluminum will oxidize and turn to powder, copper turns green from oxidization as well. The paste will prevent this oxidization process. The aluminum spring within the wire nut could and will still oxidize after time (seen it from original installs 30 years ago in electrical). The paste nearly stops this process from ever happening. Aluminum to aluminum will oxidize over time as no 2 aluminum parts are made 100% of the same material, which starts the oxidization. You leave bare aluminum out in moisture or exposed to heat and cold, the aluminum changes state. Basic chemistry my friend. ;) for the price, use the paste.

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Hugh in London
Date/Time2/6/2016 at 11:27:27 AM

Thanks to all for your informed replies. I fully understand the importance of using the approved prefilled wire connectors.

My specific questions were intended to be and should have been worded as follows:

1) Do you advise replacing the copper receptacles with aluminum compatible receptacles, or, provided the existing Al wires are not damaged, would the use of the approved, prefilled wire connector, instead of the illegal ones, be safe and sufficient to meet the requirements of the current CE CODE Handbook, by splicing the Al to the Cu pigtail and continuing the use of Cu receptacles?

2)Assuming this work is performed by a qualified electrical contractor, or properly licensed electrician, would the total wiring system now meet the requirements for an official certificate of updated wiring and electrical safety code. If so, where would I get such an authentic certificate?

3) Is this subject covered in the current edition of the CE CODE Handbook. If so, what section?

4) Are there any further specific precautions I have to make sure my contractor observes regarding working with Al wiring?

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Robert from Electrilight Ltd. in Oakville
Date/Time2/6/2016 at 12:05:20 PM

Aluminum wires to aluminum approved devices with compound best solution. Al to al with copper pigtails using prefilled approved marrettes or dry marrettes with paste, second choice. Either method is CEC compliant. Done by ameteur, not recommended but could be inspected by an inspector at The internal wiring cannot be inspected for what cannot be seen, but inspecting every box within the house and junctions can certainly tell if DIY was performed or if copper extensions lead to new devices. A panel inspection can also help view what is new and old. If you are worried, get it inspected. Dont concern yourself of CEC rules or OESC as there are 1000's of pages covering our wiring worlds.

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Hugh in London
Date/Time2/6/2016 at 2:29:25 PM

Thanks Robert. That is what I needed to know.


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