You do need a controller that will handle 30 amps if your array is rated at 24 amps STC.
Mr Wiz says it would be more honest to call that a 24 amp controller. It would be stated in the manual for it that it can do 30 amps for short periods, but it should only be operated at 24 amps continually. Or it could just clip its amps at 24.
In the case of the Solar 30 it does say it can run at 30 amps continually, so it must be able to do more than that for short periods. So if you had an array rated for 24 amps at STC you could run it with a "25" if it was clear that the 25 is 80% of what it can really do.
So for honest ratings, which is more honest for equipment to be named for its "rating"?
A. call it an "80" for its continuous ability, or
B. call it a "100" for what it can really do, and state in its manual it should only be run at 80 continually to comply with the NEC?
What is the real popping amount for a "15a" circuit breaker?
Mr Wiz says "30a worth of panels" but there is no such thing. Panels can do all sorts of amps depending, and are "rated" for one of the situations-STC It is just a WAG to give it a 1.25 margin above STC.
Actually, a 24 amp array at STC could be called "30a worth" so a 30a controller would be a good match.
