I am about to install a PIR outdoor light, there's already some wiring in place that I can use to feed it but it's a bit non-standard and/or non-conforming.
The existing outside wiring feeds a single outdoor socket and a floodlight with an outdoor switch. It's all reasonably sound and sensible using proper outdoor switches and sockets but it's not fed via an FCU, it's just connected directly through the wall to an indoor socket on a radial 20A protected circuit (well, RCBO now, so it does have 30mA RCD as well).
It *might* be that the existing switch and floodlight are 20A rated but I think it's unlikely, even if they are then the PIR I'm adding should be on a 6A or 10A protected circuit so I should really add an FCU where these are all fed from the socket indoors.
Is it OK to leave the outdoor socket in the circuit even though it will only be 6A or 10A? It's handy out there for electric strimmers and such and it's very unlikely indeed that anything requiring more than a few hundred watts will ever get plugged into it.
I could run an extra 2.5mm2 cable just to the socket but it seems a bit of extra work with little gained.