Clarke Echols wrote:
First of all, be sure the person giving you advice is qualified to do
so. You're missing a lot of better input, so I'll give it a shot.

First of all, the NEC (National Electrical Code) specifies that
circuit breakers must be sized such that they do not exceed 80% of
their trip capacity under normal circumstances. If you are running
motors that pull high currents for a short time (saws, planers,
jointers come to mind) either at start-up or during operation, you
work from maximum normal operating current, not peak-load current. A
#10 wire can carry 30 amps. A 30 amp breaker is allowed to carry a
steady-state load of 24 amps. Thus you can use a 40-amp breaker on
30-ga. wire for motor loads (actually you can use a 50-amp breaker if
you're running an arc welder). Local codes might vary, but I got
this from a retired industrial electrician of substantial experience.
You have to go to the NEC and look in the area that talks about motor
and welding loads.

You can't oversize the breaker to a subpanel because it has some motor loads
on it. That exception is meant to allow motors to start without tripping the
breaker.