I was crawling the Internet to find out what the functional earth found on some RCBOs was for and stumbled across the following video that explained it along with a full teardown of how everything works, a demo of the bimetallic strip and arc arrestor in action before then finally overloading it to destruction:

https://www.youtube.com/watch?v=gOUSDDLKICk

Thought it might be of interest to others!

I watched that yesterday (actually early this morning), I trying to
see how feasible it would be for the manufacturers to add a tell-tail
flag that would indicate if over-current or earth-leakage had caused
it to trip.


--
Graham.

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