Single cores outside enclosure

mapj1: 
 

It maybe even a C3 for the inaccessible wiring behind the downlight - depends if the cavity behind is totally enclosed and what else is in it that the wire may snag on (pipes or bits of metal for a partition or suspended ceiling full of other cables  are more of a concern than an void bounded by  only non-moving brick and plasterboard)

 

I know this is the essence of the guidance in Electrical Safety First's Best Practice Guide No. 4 … but I'm just going to deviate from type for a moment and play devil's advocate. ?

What has being inaccessible got to do with anything? If placing out of reach is only permitted in installations controlled or supervised by skilled persons (Regulation 417.1), we can't pick or choose between “can touch it from the floor” vs “can touch it on a chair” or “can touch it when I remove the downlight”

Regulation 521.10.1 does not say “Non-sheathed cables don't have to be enclosed if they are inaccessible”. Regardless of where you run the cables, Regulation 521.10.1 clearly states:

521.10.1 Non-sheathed cables for fixed wiring shall be enclosed in conduit, ducting or trunking. This requirement does not apply to a protective conductor complying with Section 543.
Non-sheathed cables are permitted if the cable trunking system provides at least the degree of protection IPXXD or IP4X, and if the cover can only be removed by means of a tool or a deliberate action.

Surely, as the risk could be fire as easily as electric shock, leads to C2 in precisely the same way regardless of accessibility, unless the installation could be considered suitably controlled by a skilled person so that placing out of reach could be considered?

mapj1: 
 

It maybe even a C3 for the inaccessible wiring behind the downlight - depends if the cavity behind is totally enclosed and what else is in it that the wire may snag on (pipes or bits of metal for a partition or suspended ceiling full of other cables  are more of a concern than an void bounded by  only non-moving brick and plasterboard)

 

I know this is the essence of the guidance in Electrical Safety First's Best Practice Guide No. 4 … but I'm just going to deviate from type for a moment and play devil's advocate. ?

What has being inaccessible got to do with anything? If placing out of reach is only permitted in installations controlled or supervised by skilled persons (Regulation 417.1), we can't pick or choose between “can touch it from the floor” vs “can touch it on a chair” or “can touch it when I remove the downlight”

Regulation 521.10.1 does not say “Non-sheathed cables don't have to be enclosed if they are inaccessible”. Regardless of where you run the cables, Regulation 521.10.1 clearly states:

521.10.1 Non-sheathed cables for fixed wiring shall be enclosed in conduit, ducting or trunking. This requirement does not apply to a protective conductor complying with Section 543.
Non-sheathed cables are permitted if the cable trunking system provides at least the degree of protection IPXXD or IP4X, and if the cover can only be removed by means of a tool or a deliberate action.

Surely, as the risk could be fire as easily as electric shock, leads to C2 in precisely the same way regardless of accessibility, unless the installation could be considered suitably controlled by a skilled person so that placing out of reach could be considered?