Sounds like we're both on the same track ere, when I ring the NIC all I get when they don't know the answer is "it's to your own discretion". They are asbestos lined and have issued a code 3 for that stating a modern equivalent is needed to replace the out dated d.b visual inspection only due to...
you'll have to do it by process of elimination, can you see the outer sheath of the cable (grey) usually if so do all of the cores go to the same switch leave your phone number if thats easier i will try talk you through it.
Have you altered any of the light fittings or junction boxes? your switching a feed some where. If you have a set of testers switch all off the switches to the off position and test each terminal to see which ones are live and report back.
Sorry, yeah thats my problem with how they have done it I could except it if they had put some kind of lighting panel in fed that with a three phase supply and then had control gear for each circuit. looks like a lot of code 2's to me.
I see your point, but lets say someone needs to add a light to a row, pulls the 3036 fuse which in turn leaves two phases live, there would still be a back feed at the neutral once disconnected, with it been a shared neutral.
I know this is not a domestic question but thought I'd give you guys a go, recently been doing a 1940's built large factory with wiring from all decades. There is roughly 130 D.Bs and C.Us mostly carrying bs3036 fuses spread over five transformers. The problem I am having is that through out...