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Half the problem I believe is when aluminium conductors get terminated under screws and in tunnel terminals, which is not what should be happening.


I assume you mean these for "tunnel terminals"
[Linked Image from ilsco.com]
That is the standard "lug" here and they seem to work fine.
Our problems were with binding screw terminals and that was really when the screws were steel. Brass screws work fairly well in the CO ALr devices

Greg Fretwell