So I don't have to ask what an RCD is, nor tell you what Dorothy Parker said...
Actually, is an RCD something different/better than a GCFI?
OK, I'm going to try sorting out, separating the circuits in my house. The house is post-Civil War (ours, not the War of Roses or whatever), and the wiring is somewhat newer....
But it's 14 ga 15A, some Romex, some BX, and everything seems to have been afterthought and tack new stuff onto the handiest J-box. Fortunately it's all visible in the basement. But stuff crosses the space back and forth. Half the kitchen, some of the living room and dining room all seem to be on one breaker, which pops frequently.
I will be trying to run new wires in to split up the circuits into reasonable extents. There will be challenges with wire-fishing, I expect. Also possibly shoveling and bucket-carrying a lot of dirt out from under the kitchen...a late extension on the house with just a crawlspace in which there is no room to crawl.
I'll ask specific questions as I go.
And I was just starting to describe another mystery of my wiring when I realized I need to look at my notes from basement exploration and see whether it is indeed a mystery or just my head swimming, as it often does when I am trying to suss out wiring.
Hence, more later!