Ring finals and fused spurs

[Fitzy]

That must be total length of cable then. But for sure the OSG also states an A1 RFC is maximum 100sqm floor space.

For a 100sqm room you could be using any length of cable from 20m to over 100m in length, dependant on the route the cable takes etc.

 

[telectrix]

for VD on a spur, I'd estimate the length of cable from one end of the rfc and add the spur length, then use mV/A/m. this would give a pessimistic figure as the VD on the rfc part would be less.