Extending an existing ring main which is on 2.5mm2 T&E, my only reasonably easy route for the extra cable is within an insulated 250mm thick (!) stud wall.
Referring to table 4D5A, I see that the existing 2.5mm2 T&E is rated at 27A if clipped direct. The same table lists 4mm2 routed in an insulated wall at the same figure - 27A.
All other things being equal, am I OK to use 4mm2 T&E for this part of the circuit, or am I missing something vital?
Cheers.
Referring to table 4D5A, I see that the existing 2.5mm2 T&E is rated at 27A if clipped direct. The same table lists 4mm2 routed in an insulated wall at the same figure - 27A.
All other things being equal, am I OK to use 4mm2 T&E for this part of the circuit, or am I missing something vital?
Cheers.