I believe this is an overload situation, as the bimetallic element appears to have initiated the trip. Look at the difference between timestamps -78 ms and -76 ms and the bimetallic element (near the load terminal/right side) has changed state and the trip mechanism has begun to operate. Very interesting video for sure, and I agree that the flash size on break also seems to suggest that it was a simple overload and not a high-current faultDo you know if that was overload or fault?
Very little flash if fault.
I think a good real world test would be to overload and short circuit a slash rated breaker on a high leg delta. As in the ~208 volt phase to neutral and see what happens.That's a pretty cool video!
I think that from a safety standpoint, they should show a breaker opening a fault of say, 3000 amps. Another at 8000 amps. Another of a 10KA breaker opening a fault of 20,000 amps them a 22KA model opening the same 20K amps. Finally, a 10Ka 120V breaker opening a 30,000 amp fault @480.
Of course this would be entertaining but I think it'd be beneficial for us to see what can happen if a breaker is misapplied. I think a lot of us don't take the destructive power of a high-energy system seriously.