On Feb 1, 10:59*am, jamesgangnc wrote:
On Feb 1, 10:27*am, ls02 wrote:

What amperage is Romex #8 copper wire? On some charts I see 40 A and
on some I see 50 A.

Individual wires you could use 8. *There are a number of calculators
out there on the web that will help with wire selection. *Distance is
a factor as well. *Plus what's at the other end. *Motors that start
under a load like a big hvac compressor may need bigger wire simply to
prevent to much voltage drop at *urge current.

In the case of general loads and Romex, it's 8 gauge for 40. With an
HVAC
load, the rules change. The circuit has to be wire sized to at least
the
minimum specd by the manufacturer. The breaker has to be sized
between the min and max specd by the manufacturer. This leads to
installations that are correct and to code, but that would be a
violation
of the rules for general purpose branch circuits.

As an example, if you have an AC unit rated for 35 amp min circuit and
rated for a breaker of 40amp min, 60 max, you could have a 60 amp
breaker using 8 gauge wire. The reasoning to this is that:

A - the AC has a high starting current that doesn't last

B- the AC has it's own built-in over current protection and is the
only
device on that circuit.