4mm spurred from ring main

[Bradley6969]

32A ring main, adding 2 more sockets off this, spark I’m working with says add radial 4mm to 2 new sockets from ring I’m saying extend ring? I know 4mm can take 32A but I wouldn’t do it his way

 

[gazdkw82]

It's a spur on a spur. I've never seen any documentation that says it's allowed if you use 6mm or higher.

 

[Wilko]

I think the design issue with adding an unfused radial at a point on an RFC is it's got the possibility to have a 32A point load. The 2.5mm ring is ok for 32A OLCP based on the load being reasonably distributed around it, which won't now be the case.

 

[Octopus]

Fused spur on ring, then as many as you like on the load side

 

[johnduffell]

Yes this ones been done to death, result is it's not a proper ring according to the informative appendix, but it can't cause an overload on the short leg as long as the joining point is more than iirc 15% of the way round the ring therefore it's ok in terms of minimise the chance of overload. Even with 2 double sockets near the end of a ring eg kitchen you could get overload so it's always a balance, just the 4mm spur stops the physical layout working in your favour.