Lou said:
I have a copper,10 gauge (3 wire - ground, neutral, hot) coming from a 30
amp (unused) breaker
Grizzly recommends 20 amp/220. Do I need to change
out the 30 breaker for a 20?

Lou, This sounds like a 110v Circuit. You need 220V for that saw. Change
the single pole (assumed) 30A 110V breaker with a dual pole breaker (20A -
220V).

Change or tag/lable the white wire as your second leg hot and you're good to
go.

Dave