The whole install is a mess. 

I'm struggling to make out the details on that picture - but the white strand sticking up between the strands used as N and those used as a c.p.c. suggests it might be an (older) version of split-con with all outer strands bare and just an insulating spacer between those used for N and those used for PE (newer versions tended to have individual 'insulation' on the N strands instead (well more of a plastic covering, not necessarily up to proper insulation standards)). With that type I think it was conventional to sleeve the N strands for termination, but if it was inside an enclosure, it's probably not an absolute requirement.

If it is split-con, while it doesn't meet today's specs, it'll act just as well as an armoured cable if struck by a digging too - provided the N really is close to Earth potential. Likewise the lack of proper insulation on the N part of the outer (just a sheath), doesn't fully comply with today's words, the actual risks will be minimal provided N remains close to Earth. Hence the earlier question about the reliability of the upstream N connections. Solid bolted connections all the way (like a c.p.c.) would be good, DP switching (or MCBs etc) including the N less so, as there likelihood of a contact failing, leaving the N open and L connected, increases; SP switching (or fuses or MCB) in the N alone would of course be right out.

  - Andy.

Unless they are heavily oxidised, it looks to me like the N strands have a thin layer of black insulation on them.

Unless they are heavily oxidised, it looks to me like the N strands have a thin layer of black insulation on them.