An electrician ran cables to a new 240V/40A outlet box ready for hookup to a Tesla wall charger. Rather than call him out again, I'm thinking of doing it myself as it appears quite straightforward. Question. I have one red, one black and one green cable. The white neutral is tucked out of there way. The green is connected to the smaller earthing terminal which leaves the live red and live black. Does it matter which way round I connect them? Looking at youtube videos it look like the red goes to the right terminal (as I look at it) and the black the left. p.s I've tested red to black at 240V, red to green 110v and black to green 110V.