Copper and Aluminum buss touch

[BigJohnny]

I have recently seen where 0n a 400 Amp 120/208V 3 ph meter main combo from Sylvainia when a lost leg during construction temp power use caused bolts that connected the CU & AL buss together burned. As a quick fix a EC re bolted and put Nolux on CU & AL buss. This is a short term solution long term problem. There is another 400 amp unit next t it and when opened it to has CU & AL buss but has plastic spacers between. I have never seen this and why would this be done at the factory or is this why Sylvainia is no longer making these units. I just don't like it and think the unit should be changed. What do you think?

 

[petersonra]

I am not sure what you think the problem is.

Are you thinking they should not have repaired the damage in the way they did?

 

[norcal]

"Or is this why Sylvania is no longer making these units." Sylvania is no longer around either under their previous name, Zinsco, or their successor Challenger.

 

[iwire]

Aluminum bus and terminals are generally tin plated so it is not an issue.

All the 'no-ox' is doing is making a mess.

 

[jim dungar]

As iwire said; the 'goop' is simply making a mess.

The biggest problem is the apparent lack of expansion compensation washers, like Bellville ones.

 

[GoldDigger]

As iwire said; the 'goop' is simply making a mess.

The biggest problem is the apparent lack of expansion compensation washers, like Bellville ones.

:thumbsup:
There would also be concern about galvanic corrosion IF the joint were exposed to weather or high humidity, but the scale of the connection would make that a long term concern only.

 

[jim dungar]

:thumbsup:
There would also be concern about galvanic corrosion IF the joint were exposed to weather or high humidity, but the scale of the connection would make that a long term concern only.

This is even less of an issue if the aluminum bus bar is tin-plated.

But left as shown in the picture, I would expect another failure, someday.