I might have made a DIY mistake...
I have recently installed under-cabinet lights in my kitchen - a 12V screw-fix kit special. Added 30A Junction box in my ring-main, then from this buried a cable in the wall to the top of the cabinet to a FCU, then on to the transformer. The thing is, I used 1.5mm T&E - I figured as there is now a 3A fuse effectively in this cable, it could never draw enough current to need more - but I now read that is wrong (see below).
Why do you need to use the same size cable running out of the junction box as that of the ring main running though it???
I have recently installed under-cabinet lights in my kitchen - a 12V screw-fix kit special. Added 30A Junction box in my ring-main, then from this buried a cable in the wall to the top of the cabinet to a FCU, then on to the transformer. The thing is, I used 1.5mm T&E - I figured as there is now a 3A fuse effectively in this cable, it could never draw enough current to need more - but I now read that is wrong (see below).
Why do you need to use the same size cable running out of the junction box as that of the ring main running though it???
The drawing says it all, but the cable to the fcu MUST be the same size as that which it is connected to.
That is why the JB has 2.5 t & e running through it and to the FCU, but only 1.5mm t & e from the fcu to the light