Aldav53,
As I understand it, there are only three methods left that we can use on copper/aluminum splices in the #12 and #10 gauge branch circuit situation.
1. Little split bolts with Al/Cu rating. (very bulky after taping - shrink tube?) I don't recommend it.
2. Amp's COPALUM Safety Connector. Last I knew it required factory training of the installer with certification before one could buy the connectors. It IS a great product, just too controlled for my needs.
3. Ideal's Twister 65 (listed for Al to Cu only - not Al to Al)
It's important to note that all other wirenuts dropped the Al/Cu listing back in the late Eighties. With or without oxidation inhibitor, regular wirenuts are not listed to connect Aluminum to Copper.
Tightening the terminal screws on old devices doesn't address the problem created by the screw and the wire having markedly different rates of expanding when heated. The Aluminum expands faster, it crushes itself under the screw. CO/ALR terminal screws are made to minimize this.
The old aluminum (manufactured pre-1975) breaks after time where nicked. Care must be taken to avoid that.
I agree with Redsy, my choice of connecter is the Twister #65. I, too, have had good results. I do, however, really pay attention to what I'm doing when I install them. . .I don't hurry or just slap them on.
Al
