Lost one phase of 200 amp service panel, power company says they are providing fully

[Ballvalve]

I Guess we need to order a few more cans...


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And some more Vaseline for my battery terminals...

Just trying to say that connections of dissimilar metals do not like oxygen and water. I am an advocate of insulation on electric wires in conduit, although the power companies apparently are not, outdoors in the air.

And mainly that our electric panels have a huge room for improvement in design and safety.

 

[Jadnashua]

Aluminum almost instantly 'rusts', i.e., gets a coating of AlO2 on it (which doesn't change color like iron rust does). But, unlike iron whose rust ends up larger and flakes off, aluminum 'rust' ends up nearly exactly the same size as the metalic material beneath it and thus protects it. On iron, because the rust ends up larger, it exposes more elemental iron beneath, and thus rusts more. IOW, aluminium is almost 'self-healing'. You need enough contact pressure to minimize the additional resistance of that AlO2 coating, there is nothing you can do to prevent the 'rust' in the first place. Add that to the fact that Al expands and contracts a bit more than say copper, and the torque applied and terminal design becomes more critical to a long service life on the connection.

On distribution lines made of Al, they don't 'corrode' or 'rust' away because of the coating they get which protects them.

 

[Sponsor]

 

[DonL]

Good info Jim.

I think the the Quality of the aluminum has a lot to do with its deterioration.

I use a lot of aluminum heat sinks on the electronics that I build and if the aluminum is not anodized, then I will paint it with Acrylic.

Works good and last a long time.

 

[Ballvalve]

On distribution lines made of Al, they don't 'corrode' or 'rust' away because of the coating they get which protects them.

Precisely why we need to 'coat' our connections in our primitive electrical panels with the contacts and screws with one size fits none.

 

[DonL]

I think that aluminum should only be allowed for making Beer Cans, Even then it leaves a after taste, but is the best of quality.

Buy copper wire, and Lube it up to fit those aluminum connectors that "Make and Break"

Aluminum wire in this part of the woods will not last as long as a 12 pack.

 

[Jadnashua]

Precisely why we need to 'coat' our connections in our primitive electrical panels with the contacts and screws with one size fits none.

Again, you're missing the point...essentially ALL aluminum has an oxide coating on it...nothing you can do about it, adding an anti-oxidant won't prevent that. The only saving grace on aluminum oxide is that it is so close in density and size to elemental aluminum that it prevents additional al from contact with oxygen, and thus 'seals' the surface. If a connector is designed knowing this (one reason why Al wire generally needs to be larger gauge than Cu - increased surface area contact has less resistant), then extra stuff is irrelevant and may degrade it.

 

[Ballvalve]

Very odd reply. I suggest you look deeper into the requirements for coating aluminum contacts in panels. Go back a bit and check some of the links, and then search for electrical fires and arcing due to aluminum wires that have oxidized and loosened due to its thermal expansion/contraction rates inside of the very poorly designed terminal connections in typical panels.