He picked up a garage unit from Screwfix, and asked me how to wire it. I **WAS** quite confident I knew (see linked pic).
Problem is (and what's thrown me), is the spare pin in the bus-bar. What's the point of the insulation shroud, if there is a pin to get a shock from?
Am I missing something obvious, or doubting my own ability? (apologies for the old-skool wiring colors)