CU to AL

Bi metalic shrims

Tin the copper first.

Smear "Densal" jointing paste on each face before joining.

Hi thanks

I wasnt logged in when I asked the question. Im in Malawi (wheres that? east central africa, where madonna buys her babies) we dont have bi metal shims or copper grease or pretty much anything readly avail. I can get solder, is it good enough?

It's been done; It's not recommended, especially outdoors where it's exposed to weather. If you are joining the busbars directly, tinning (solder) is a good idea - don't know how well it will work on the aluminum, but at least on the copper. Stainless steel hardware is best if you can get it.

See the following article that seems to agree with this:

http://ecmweb.com/images/archive/1000_bolted_joints.pdf

Practice at my company when we have to connect copper to aluminum conductors is to use bronze connectors on the copper cables, with Penetrox joint compound. We also try to put the aluminum so it's above the copper. This is so that the copper oxides don't get washed down onto the aluminum and cause corrosion. Check this out:

http://fourseasonsroofingandsiding.com/mixmetals.htm

Don't try tinning aluminium, just tin the copper.
If you can't get jointing compound use Vaseline.

Thanks Guys.

Its a new 2000 amp incommer to an indoor panel. I will just tin the copper busbar.

Please make sure you use something to stop the aluminium oxidising / corroding. Vaseline must be available.

Under no circumstances use copper grease it will corrode within hours. I found out the hard way!