That's 3.3 amps behind the breaker. So if your wiring is set up for 16 amps you can now draw 19.3 amps before the breaker kicks in. That's within the safety margin. But if you allow PV to feed in more you exceed the safety margins and can cause the wiring to overheat.
Hmm, I guess you're right. If your oven is plugged into a different breaker than the one where you plug in the solar panels, that doesn't happen, but most people won't know which outlet is on which circuit. Thank you for explaining!
caveat - 20 amps on a b16 breaker will take a very long time (minutes to hours) to trip; in practice, you may never see it tripping during normal usage, but yeah your walls will get a bit warmer.
