I have bought an ELCB and a mini DB board for a small solar/inverter project. My understanding is that an ELCB trips when there is a potential difference between earth and neutral. The diagrams I've seen online all show an earth connection to the ELCB, for example:
However, when I try to connect up my ELCB, I can only see the four main connections (live and neutral, in and out). Here, pics:
There are no other connections apart from those four. How is the ELCB earthed?
The only way I can think of is through the connection to the metal rail on which all the breakers are installed. However, the backing of the breaker does not seem to be conductive.