Beware The Borrowed Neutral

[sparky1502]

sorry but why would u broow the neutral wire for the lighting circuit

 

[NoSparks]

The concept was that you had a live wire from the downstairs lights in the switch in the hall. This would be connectd to the common for the landing light. Then a 2 core (often without cpc) connected to L1 & L2 (although they were not marked as such in those days) to the landing switch, then a single core to the landing light, before "borrowing" the neutral of the upstairs lights.

Why? probably to save on the cost of 3 core between switches, or maybe because it meant that the electricians did not have to carry 3 core cable, or maybe just because that's the way everybody did it! Also in those days everybody had a pendant and there was no concept of changing a light fitting, so I suppose the dangers were not even considered.

What concerns me is what practices we are using today that will be considered dangerous in 50 years time? Maybe putting wire in the wall at all. I can just imagine it " Those idiots back in 2010 used to put cable in the wall. Why didn't they use proper radio switches?"

 

[hotXbun]

OK .... so I gather it's probably just me but something I find hard to resolve ...

I don't know about anyone else but I haven't come across a customer who phones me and says, "Hi hotcrossbunny, please, I want one of those new fangled 17th Edition all singing all dancing consumer units that every plumber/carpenter/plasterer/tiler/decorator/roofer/apprentice insists I need .....................and then said customer rejects the idea of replacing the borrowed neutral!

As I understand it, some interfering busybody comes along (most prob a plumber ) and tells customer that all is not well .... "I'm sorry to tell you this, but your electrics are not up to date. You need an "update"! Said customer, being mighty impressed, pleads with plumber for guidance and along comes PartP to the rescue ........ No doubt he/she(!?) has a "P" emblazoned on the underpants worn 'Superman' style ..... "Hi! Part P man (don't ask which part) to the rescue! ... What's your problem?" ... Hmmm,

Excuse the digression, but why is it ok as long as everything is 50mm beneath the surface? What is it that the plumber knows and I don't?????...

 

[NoSparks]

Maybe the plumber on his training course was told about BS7671.

 

[Gravid]

"As I understand it, some interfering busybody comes along (most prob a plumber ) and tells customer that all is not well .... "I'm sorry to tell you this, but your electrics are not up to date. You need an "update"! Said customer, being mighty impressed, pleads with plumber for guidance and along comes PartP to the rescue ........ No doubt he/she(!?) has a "P" emblazoned on the underpants worn 'Superman' style ..... "Hi! Part P man (don't ask which part) to the rescue! ... What's your problem?" ... Hmmm,"

HaHa brilliant, wish I'd got part P underpants instead of a mouse mat.

Maybe they'll stop selling screws and nails longer than 1.5" to anybody who owns a house soon. Who knows why 50mm ? All i know is it says so on page 100 BRB reg 522.6.7, anything less than or not complying with........, needs an RCD.