As AVO mentioned, there is not an RCD in the fusebox you have photographed , this looks like a sub board off your main fuseboard ? where there may be an RCD, if it is the B10 MCBs that are tripping this makes sense if the fuse is also blowing, however i am confused about the role of these transformers , are they remote from the Rako kit as it looks like the actual lights are commoned together on the output of the transformers.
Dont suppose you have the Rako project file to hand ?
What i would have expected is that each lighting zone is connected to an output directly of the Rak dimming unit. So do these transformers work for just 2 zones, if so, and the lamps are LED , i would be looking at removing them and installing the appropriate dimming LED driver to replace these transformers.
Again a call to Rako will confirm whether these transformers are appropriate for this installation. I suspect not