- Reaction score
- 645
Hi 2 all,a ring main is installed in a roof space of a bungalow using 2.5 t/e,protected by a 32amp rcbo,the cable laid on top of existing insulation,years later,we r all goin green,the thickness of the insulation exceeds 100mm,how does this effect the final ring circuit calculations etc.If installing a 2.5 radial in the same conditions ref method101 the cable is derated to 17 amps,so is that the case of a ring main circuit,ie;32 amps now rated at 17amps,& protected by a 16 amp rcbo & not a 32 rcbo cheers hav a nice day,ta ra bab