I am planning a garden installation where there is already a 4mm SWA available outside. My plan would be as follows:
4mm radial from DB between 3 double sockets and 3-4 FCUs for lighting/pond/heaters. The accessories can accept 2x 4mm cables. The circuit will be protected by a 25A SP RCBO 30mA Type A. The total distance of cable from start to finish circa 30 metres and will be buried in various locations and run surface elsewhere.
Electrically I can’t see anything wrong, and I don’t see any benefit in using RCD sockets as there is an RCBO at the start of the circuit.
One of the sockets may be used for one of these blow up hot tops, which come with in-line RCDs. The supply is TN-C-S so this will be exported.
Am I missing anything? Would I be better off TT’ing the potential socket that’s going to be used for the portable hot tub? I’ve seen lots of mixed opinions on this subject, some export PME, others don’t.