We are so alike yet we are Dissimilar, Copper and Aluminum wires.
Submitted by DonHester on Wed, 04/10/2013 - 19:57.
We are so alike yet we are Dissimilar, Copper and Aluminum wires. Wenatchee Home Inspections
Ah the things we will see during a home inspection.
Here we have another one of those things that you must be aware, terminating copper and aluminum conductors under a common lug or commonly called double lugged or even more commonly called double tapped.
Copper and aluminum are considered dissimilar metals and as such special precautions must be adhered to. They should not touch.
Conductors of dissimilar metals must not be intermixed in a terminal or splicing connector where physical contact occurs between dissimilar conductors.
This must be performed in a device (lug/splice) that is identified for this purpose and conditions of use.
So here we have a double lug with copper and aluminum conductors in full contact.
NEC section 110-14(a). In general conductors must terminate in a proper manner. The terminals must be rated for the conductor material, copper and aluminum cannot be mixed, inhibitors and compounds must be identified for the conductors, and termination's must be torque according to the manufacturer's instruction [110-3(b)]. Naturally the termination's must be tight, and only one conductor is permitted under a terminal unless the terminal is identified otherwise.
From the Washington State Labor and Industries which oversees the Electrical Code in Washington State.
-Don’t mix copper and aluminum conductors in the same terminal or splicing connector unless it is listed for the purpose.
-Use lugs rated for copper if using copper conductors and aluminum rated lugs for aluminum conductors.
-When multiple terminations are made under one lug the terminal must be rated for the combination of multiple conductors used.
So we can see that unless this has been done with a proper it is not proper and is a safety issue and a code issue. But home inspectors are not code inspectors… or are we?
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