Lamp holder - live and neutral?

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I have the lamp holder below. So far as I can see there are no markings for live and neutral. Does it matter which way round they go? Also, how are they secured given there are no screws to lock the wires in place?

IMG_0481.jpeg


I’m replacing the cable on a fitting to better match another fitting; while it’s still a simple job, it’s not proved as intuitive as I’d hoped to dismantle and reassemble!
 
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If there is no cord grip in a lampholder I've always tied a knot in the cable and screwed the cover onto it so that the wires won't pull out of the terminals. The polarity does not matter on that type of lamp holder only on E.S. or S.E.S ones.
 
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Use your multimeter to figure out which terminal connects to the centre pin, and connect that one to live.
 
As above, with an ES the polarity is important. Get it the wrong way around and it means that the threaded part is live. Makes no difference to a bayonet bulb though
 
As above, with an ES the polarity is important. Get it the wrong way around and it means that the threaded part is live. Makes no difference to a bayonet bulb though
It‘s not quite as important with modern EU lamp holders though. Look at this US one:


The whole screw shell is one piece of metal, so as soon as the lamp touches that, the lamp‘s screw thread is connected to the supply.

Compared to a modern EU one


where the screw shell is a separate piece fixed to the ceramic and the only live part is the small tab on the side that touches the thread of the lamp only when the lamp is screwed all the way in. In some instances the shell isn‘t even metal but the threads are moulded ceramic or plastic.
 
PS - the proper terms are Line & Neutral - they are both Live
Strictly speaking true - but, as I recently observed, very very few non-electricians will have any idea what "Line" means in this context, so one has to wonder what terminology is appropriate for "clear communication" with the general public.

I also wonder exactly what 'we' mean by "Live". BS7671 says:
Live conductor (see Live part).
Live part. A conductor or conductive part intended to be energized in normal use, including a neutral conductor but,
by convention, not a PEN conductor
... which leads me to wonder what is meant by "energising" a neutral conductor (BS7671 offers no definition).

Kind Regards, John
 
Some good points made, although in the UK we use a polarity sensitive system, where often only line is switched or fused, that is not true world wide, and even in the UK we have a 110 volt system where there is no neutral, just line 1 and line 2, plus earth.

Reduced low voltage (110 volt) has basic same rules to low voltage (230 volt) so if you can use E27 bulb with reduced low voltage although most had a rubber shield.
 
Some good points made, although in the UK we use a polarity sensitive system, where often only line is switched or fused, that is not true world wide,
Yes, if one has a truly 'floating' supply, or one which is 'centre-tapped' to earth, then one just has two "Line\s", or two "Lives". However if, as I would think it far more common, one side of the supply is connected to earth at the source, then there is a clear distinction between 'Line' and 'neutral' - and, to my mind, no particularly obvious reason why the "neutral" should be called "Live".
 
I also wonder exactly what 'we' mean by "Live". BS7671 says:

... which leads me to wonder what is meant by "energising" a neutral conductor (BS7671 offers no definition).

Kind Regards, John
Indeed,

If one regards "energised" as "at a hazardous potential", then most neutral conductors would not be "live conductors" (exceptionally, if you had for example a floating bipolar or 3 phase system it could make sense to talk of a neutral conductor that was not referenced to earth).

But if that was the case there would be no need for the "by convention, not a PEN conductor".
 
559.6.1.8 In circuits of a TN or TT system. except for E14 and E27 lampholders complying with BS EN 60238, the outer contact of every Edison screw or single centre bayonet cap type lampholder shall be connected to the neutral conductor. This regulation also applies to track mounted systems.
537.2.1.1 Every circuit shall be capable of being isolated from each of the live supply conductors. In a TN-S or TN-C-S system, it is not necessary to isolate or switch the neutral conductor where it is regarded as being reliable connected to Earth by a suitably low impedance. Provision may be made for isolation of a group of circuits by a common means. if the service conditions allow this.
Clearly with the British 110 volt system both lines must be switched, but to use E27 the lamp holder would need to comply with BS EN 60238.

The problem is the standard costs, so I have no idea what the standard asks for I would expect the holder to look like this
1722564359347.png
where the threads are plastic and there is an outer ring, so one can't get one's fingers near the screw thread when putting the bulb in or out of the holder.
 
Strictly speaking true - but, as I recently observed, very very few non-electricians will have any idea what "Line" means in this context, so one has to wonder what terminology is appropriate for "clear communication" with the general public.

I also wonder exactly what 'we' mean by "Live". BS7671 says:

... which leads me to wonder what is meant by "energising" a neutral conductor (BS7671 offers no definition).

Kind Regards, John
I don`t fully agree with you on that one Kiddo.
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.
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).
Any conductor that carries current under its normal intended function as some says.
A protective conductor carries current ) theoretically and normally only under , for instance, fault conditions therefore not Live usually but can become Live under fault conditions.
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.

So L(Line) & N are both Live and E isn`t . N can easily become Line in some circumstances so yes lets class it as Live I thinks.

We have to live with the fact that L(Line) is often commonly referred to as L(Live) by all and sundry.
Case in point, my very first Wiring Regs course, the tutor for a week or three kept referring to Live instead of Line, I thought "well there are about 25 in this class, mostly electricians , and the majority if not all usually refer to "Live and Neutral" Line not being mentioned.
Then he went thru Part 2 of the regs (definitions) with us and when it came to the term Live he read it as if for the first time he noticed that he along with everybody else had actually been using the wrong term.
He knew all along but his method of teaching was to give the impression he had only just read himself and realised during the last 20 mins.
Brilliant knowledgeable bloke and a great teacher too. He always gave the impression that he was learning along with us.

The "convention" of not referring to a PEN conductor as Live is in my humble opinion not the best idea, I would still prefer to consider it Live.
Yes we are all walking on a Live Wire in effect ;) .

Anyway that's just my little opinion.
 

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