splicing old aluminum to new aluminum

[malachi constant]

Hi all,

I have a situation where aluminum feeders and branch circuits were installed circa 1978 in a multi-family housing property. 175A 3p aluminum feeders come into the building and run vertically through three floors. We are remodeling the first floor in such a way that all vertical distribution will be interrupted. We do not have the opportunity to replace the old aluminum.

I want to make sure I engineer the interception of the aluminum correctly. Assuming we provide new aluminum conductors, is there anything special that needs to (or should) be done? For instance I found an old thread (http://forums.mikeholt.com/showthread.php?t=95296) that details a copper/aluminum splice kit. Is something similar necessary for "old aluminum to new aluminum" situations?

Thanks!

 

[Ponchik]

Why not use a butt splicer that is designed for Aluminum?

I don'y think there is anything special that you need to do.

View attachment 14678 or View attachment 14679

 

[jeremy.zinkofsky]

Hi all,

I have a situation where aluminum feeders and branch circuits were installed circa 1978 in a multi-family housing property. 175A 3p aluminum feeders come into the building and run vertically through three floors. We are remodeling the first floor in such a way that all vertical distribution will be interrupted. We do not have the opportunity to replace the old aluminum.

I want to make sure I engineer the interception of the aluminum correctly. Assuming we provide new aluminum conductors, is there anything special that needs to (or should) be done? For instance I found an old thread (http://forums.mikeholt.com/showthread.php?t=95296) that details a copper/aluminum splice kit. Is something similar necessary for "old aluminum to new aluminum" situations?

Thanks!

Treat it the same way you would a copper/copper splice exept use Aluminum components. The only thing I would add is the application of an anti-oxidant compound to the conductors before insertion into whatever medium you decide to use for the splicing. However, that is not a code requirement merely a precaution.

 

[GoldDigger]

Treat it the same way you would a copper/copper splice exept use Aluminum components. The only thing I would add is the application of an anti-oxidant compound to the conductors before insertion into whatever medium you decide to use for the splicing. However, that is not a code requirement merely a precaution.

Given that you have old Al which has a greater mismatch of thermal expansion than the newer stuff, I would lean in the direction of a crimp with anti-oxidant or a screw terminal method rated for Al, also with anti-ox.

 

[kwired]

Given that you have old Al which has a greater mismatch of thermal expansion than the newer stuff, I would lean in the direction of a crimp with anti-oxidant or a screw terminal method rated for Al, also with anti-ox.

Me too. It was the older alloys that did require antioxidant use, newer alloys don't require antioxidant, though many still apply it because that is what they always have done.