Lamp holder - live and neutral?

[ericmark]

Line conductor. A conductor of an a.c. system for the transmission of electrical energy other than a neutral conductor, a protective conductor or a PEN conductor. The term also means the equivalent conductor of a d.c. system, unless otherwise specified in the Regulations.
Live conductor (see live part).
Live part. A conductor or conductive part intended to be energised in normal use, including a neutral conductor but, by convention, not a PEN conductor.

I do note:- "by convention, not a PEN conductor." so it does seem, even back in 2008, there was some uneasiness at not classing the PEN as live. Back in 2008 we had for caravans and motor caravans "NOTE: In the UK, the ESQCR prohibit the use of a TN-C-S system for the supply to a caravan." and clearly if a motor caravan came under that rules so would have any other similar motor vehicle.

So we have hot tubs, patio heaters, and EV's which are often not class II, and we are now starting to switch the earth, which seems to go against the grain, I looked for socket outlets used outside, but that must have been the 16th edition, the 17th needed all under 20 amp to be RCD protected, but to my mind a socket outlet which is likely to be used outside the protective equipotential bonding zone should not use TN-C-S earthing system. The earth is connected to my external socket, but I only use class II equipment in it.

However, lighting seems to be the odd one out, no tool required to take cover off a ceiling rose, and the protected against an object 12.5 mm (IP2X) is also not complied with. We have had plug in ceiling roses for years, but except in a bathroom, they were not RCD protected, so why lights with plugs and sockets is different to power plugs and sockets I don't know.

I would think the light fitting shown is BS EN 60238 but can't see any marking on the picture.

 

[JohnW2]

I don`t fully agree with you on that one Kiddo.

I'm not sure what you are disagreeing with since, other than my first point (with which you say you agree), I was merely 'asking a question' (saying that I 'wondered' what the term meant), not making any statements/assertions!

Point 1/ Very few non - Electricians yes and quite a few electricians too , so no argument there, I think just a footnote about Line would suffice at worst so not actually a problem much.

Indeed. However, why introduce a word that very few people will understand when there is an alternative (even if technically strictly 'incorrect') that they do understand?

Point 2/ Energising a N conductor - a conductor with the potential to have current flow - whether we consider that Electrons flow thru from end to end or merely bang into each other and the last one falls out sort of thing it is important to remember that they (it) could flow thru you and that could be a bit of a hazard under some conditions - so energising/energised seems clear and no problem to me.
I look on the term "Live" to mean a current carrier under normal service (or intended to be, say with a switching circuit). ...

That would not be unreasonable, but I don't think I have seen any 'official definitions' which say that. In any event, it does not alter the fact that most people will probably get confused (potentially with dangerous consequences) when a neutral conductor is descibed as "Live".

Another useful thing about terming N as a Live conductor is it gives us a gentle reminder that N can become Line under some not extremely unusual conditions such as the age old borrowed N scenario.

Maybe, but I'm not sure that the situation in which there was such a fault/error in the installation would really fall into your definition of "under 'normal' service conditions", would it?

We have to live with the fact that L(Line) is often commonly referred to as L(Live) by all and sundry.

That's my point. I really see little point (and some downsides) in trying to promote the use of a term which almost no-one will correctly understand, even if it is (by definition) 'technically strictly correct'). As I often say, I would say the essentially the same about trying to persuade the general public to regard 230 V as "Low Voltage".

Kind Regards, John

 

[ebee]

Maybe, but I'm not sure that the situation in which there was such a fault/error in the installation would really fall into your definition of "under 'normal' service conditions", would it?

I`ve seen a few folk disconnect N and work on it (The floating end) without checking that it can not become L via a lamp etc.
Calling it Live might make them think? or might not

 

[JohnW2]

I`ve seen a few folk disconnect N and work on it (The floating end) without checking that it can not become L via a lamp etc.

Maybe - but, again, I'm not sure I would call that "in normal service"!

Calling it Live might make them think? or might not

Again, maybe, but those needing to be reminded of the potential hazard would probably not use the word 'live' to describe the neutral, anyway!

 

[Ragnar_AT]

There are some strange legacy supplies left in parts of Europe. Belgium has extensive 133/230 V TT supplies (the centre of the transformer is earthed but no neutral conductor supplied throughout the network), Italy and Spain have similar supplies but apparently in much smaller numbers. Norway has widespread 230 V three-phase IT supplies with all their drawbacks. In none of these countries double-pole switching is required as far as I know, nor was it in Germany when there were still bi-phase supplies there. I assume in that case it would be sensible to connect the switched live to the outer shell of the Edison socket and the unswitched live to the centre but that's only an educated guess.

 

[ebee]

Maybe - but, again, I'm not sure I would call that "in normal service"!

Depends how you compare normal and common or common not uncommon.
I know a few folk I do not not consider Normal cos they do daft things but they are quite a few of that so it becomes "Normal" by not being rare.

Example - Car Drivers - when I first started driving their were some idiots about there always were some, nowadays there are more and more drivers and sadly more and more percentage of bad drivers too, all this builds up to combine total idiots driving cars being almost normal.
Increasing risks to themselves and everyone else, getting everybody so wound up, including themselves, increasing wear and tear on a car to gain a half second advantage in a 10 mile journey becomes normal to some folk. Normally

 

[JohnW2]

Depends how you compare normal and common or common not uncommon.

I would suggest that the behaviour you have described is neither 'normal' nor 'common'

 

[ebee]

I would struggle to classify as uncommon sometimes though.
The gen term "Common Sense" I prefer to rename "Uncommon Sense" in many things to do when dealing with people in all sorts of topics, ( purely to remind oneself that common sense is not as common as we would like to think it is)

 

[ericmark]

Oh, to be an English student, and define normal and common. In a sense that is the problem with the electrical industry, we use common words to describe items outside their normal use. Then expect the normal man/woman in the street to ken what we are on about.

So we have a circuit (An assembly of electrical equipment supplied from the same origin and protected against overcurrent by the same protective device(s).) but a fused connection unit does not form a circuit, as it is a BS1363 device which is used in a final circuit, so if final, you can't have a circuit after it. And that's final!

But normally we class normal as not being under fault conditions. Does that make common sense?