Recently they were flogging off some Wylex shower RCDs cheap in B&Q, so I bought one. My main consumer unit doesn't have an RCD, and I thought I may as well have a bit of extra protection on the shower, especially for the few quid they were asking.
Now I'm trying to understand the cryptic to non-existant instructions from Wylex. Inside the plastic enclosure there is the RCD device. It has four screw terminals, two at the top and two at the bottom. The top left one has an "L" next to it, the other three are unmarked. So which cable do I put where? There aren't that many possible permutations, but I don't think guesswork is a good idea in these situations. I know that I need to connect the earths separately using a connector block.