...I've drifted from the original thread - which was about aluminum as a FEEDER conductor.
No you didn't. That was a different thread.
I am looking at using aluminium #6 and larger providing they are compact aluminium. Another attribute of compact aluminium is the aluminium equal to copper is actually smaller in diameter. in other words, although you would need a 4/0 aluminium conductor in place of a 3/0 copper, the 4/0 is actually narrower then a 3/0. This means no need to up size a conduit to accomodate the "larger" wires. This is also a benefit if the existing copper conductors in a raceway need replacing like to damage. If the customer will accept aluminium, they can save a few pennies. Outside of the difference ampacity size for size and terminal requirements, if you can ignore the stigmatism of old AL wire, why not use aluminium?
