I agree with Graham - I'd note that basic protection isn't quite the same thing as basic insulation  - basic protection being more to do with prevention of electric shock without a fault being present (direct contact in old money), while basic insulation (functional insulation in old money) often does provide basic protection, it can also be needed for other purposes - functional insulation of course, but also helping to prevent shock under fault conditions (including faults on other circuits).

   - Andy.

I agree with Graham - I'd note that basic protection isn't quite the same thing as basic insulation  - basic protection being more to do with prevention of electric shock without a fault being present (direct contact in old money), while basic insulation (functional insulation in old money) often does provide basic protection, it can also be needed for other purposes - functional insulation of course, but also helping to prevent shock under fault conditions (including faults on other circuits).

   - Andy.

Yes, correct on all the statements you mentioned.

The reason i am inclined to say i am correct with my assumption is that the two positive cores will be insulated therefore providing the functional insulation role even though the negative pole is uninsulated and the voltage will be below 30V DC as per the reg. Similar to trucks where the negative pole is effectively the chassis (BS 7671 does not apply to the automotive industry). All connections including the bare conductor will be enclosed in a plastic junction box and not in publicly accessible locations.

Section 715.414 makes reference to bare conductors for SELV lighting when the voltage level is below the regs limits.