On Apr 5, 2:06*am, Tom Horne wrote:
wrote:
On Fri, 04 Apr 2008 17:28:00 GMT, M Q
wrote:

If 90 amps is the ampacity of the circuit, I get 3ga for 75C wire and
4ga for 90C wire.

Nope. the 90c column is generally just for derating purposes. You
won't find any 90c rated lugs on the breaker end or the heat pump ernd
so you can't use that column for rating the ampacity of the circuit.

You can in fact buy 90C terminal blocks and install them bridged by
short lengths of the larger conductors to the breaker and heat pump
terminals but it would only be worth the bother on a very long run or on
very large conductors.
--
Tom Horne

"This alternating current stuff is just a fad. *It is much too dangerous
for general use." *Thomas Alva Edison

Not 'one' wire; surely at least two (neutral and live, or two 230 volt
live, or two phase wires if wired from a 3 phase supply) plus a
ground wire; each of appropriate gauge, as discussed above.
And if you don't get it right it won't get approved might have to be
redone and might become an insurance liability or cause another
fire??????