It's basically a GFCI, not a breaker. They can almost always be identified by the test button, I've never seen one without it, nor a breaker with one.
Exceeding the current will kill it in non-guaranteed ways, including fire, short-circuit, or alien invasions. It's not meant to trip on overload, but on any connection between live and ground.
Please use the test button asap. If it does not trip when using the test button, get it replaced. The current limiter should have saved it, but it's better to be sure.