Adding outlets to house wired with aluminum wiring

[Marybeth Valenti]

How do I safely add a copper wired oulet off of aluminum wires? I first need to create a J Box at the existing aluminum wires, and then run 5 feet of romex to the new oulet location.
Thanks so much, Marybeth

[dkerr]

http://www.homewiringandmore.com/aluminum/index.html

This is an article on our homewiringandmore site dealing with aluminum wiring, "safe or not" ?, it even mentions special ALR rated wire nuts to join aluminum to copper.

This should give you some info on the subject until other replies come in.

[Wgoodrich]

YOu did not clarify what amp rating this aluminum wiring you want to tap onto. If this is 14 awg aluminum do not tap on to that as a branch circuit extension.

If this wire is a 12 awg 20 amp aluminum wire then you may tap a 14 awg 20 amp copper wire to that aluminum but only using a connecter approved for mixing copper and aluminum under the same connector. YOu must use an alloy split bolt with an allow divider separating the two dissimler metals. You may use a purple wire nut that has a grease compound inside that iwre nut but only if this purple wire nut is listed for use with a mix of aluminum and copper wire.

Remember that copper and aluminum will react chemically to each other unless properly connected by UL standards using listed wire nuts for that purpose.

Any junction must be contained within a box. Most often if this is a 15 amp aluminun receptacle branch circuit 12 awg then you may connect both copper or aluminum under a device [aka receptacle or switch] connection marked CU/ALR. Do not connect aluminum to a device or connector listed only for copper CU or copper to a device or connector listed only only for aluminum AL.

Do not connect a conductor that is rated less amps than the existing wire is rated in amps. Often times people try to connect to a large amp wire dropping to a smaller amp wire in midcircuit. This is not allowed as a branch circuit extension.

Do not try to split a 220 volt branch circuit into a 120 or two 120 volt circuits unless this wire is rated in amps equal to the ampacity of the branch circuit extension being added or to any 220 volt branch circuit that is less than a black, red, white and bare. 3 insulated and one green or bare wire. If you have a 220 volt branch circuit but only have a black white and bare or a black red and bare then you have not grounded leg [aka neutral] or no true neutral conductor to serve a 120 volt branch circuit extension.

Good Luck

Wg