Is the issue here that the ring has 2 legs and we assume the load is equally spread so we can have the ring in 2.5mm rated 24A per leg on a 32A breaker, but the same radial would be on a 20A breaker as only 1 leg.If we spur off a ring to another socket would 4mm be more appropriate than 2.5mm?
how much power can the socket safely draw?
single... 13A
double... 20A
why go for 32A capacity....
or are we talking off taking a "radial" branch off a ring...
e.g. Spur off spur off spur...
You still need to consider the current rating of the accessory where the spur/radial branch actually joins the ring...
e.g. a double socket on ring with a double socket spurred off it, will be carrying all of the spur current across the screw terminal joints in the back of it.
IMHO if your spur/radial branch is gong to be carrying so much power it needs 4mm,
I would think you need to look at proper radial back to CU,
or full extension of the ring circuit to ensure balancing load.
So if you are expecting big power consumption down your new spur branch, the ring as a whole may not be suitably balanced.
But if NOT need high power consumption... then no need for 4mm anyway!
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