Consumer unit layout

[JohnW2]

Yes! The definition of "luminaire" I can find is: "A lighting unit consisting of one or more electric lamps with all of the necessary parts and wiring."

I presume that is a dictionary definition. However, what I was asking for views about was the interpretation of the BS7671 definition.

Anyway, in terms of 'your definition', would you regard a pendant as a 'luminaire'? ... or, as I keep asking people, is there anything powered by electricity which produces light (other than neon indicators etc.) which you would not regard as a luminaire?

... and, even of there is a dictionary definition, have you ever heard anyone other than an electrician (or 'related' person) use that word (other, maybe, than in relation to some fancy light fitting they bought in France ).

Kind Regards, John

 

[Adam_151]

Well, who knows - but I think one probably has to be a little silly to think that the BS7671 definition really includes a pendant (or, indeed, anything which consists of just a lampholder and shade or reflector).

What are you suggesting - maybe that, for some bizarre reason, the electric industry has chosen to use the word 'luminaire' to mean what the rest of the English-speaking world would call a 'light'? Indeed, if that were the case, a BS7671 definition (let alone a fairly 'complicated' one) would not really be necessary - or, at least, it could be simplified to just say something like "anything which creates light out of electricity".

I'll agree with you only as far as that I do think its a rather pointless term, but it is clear that it was intended to cover pendants and batten fittings as well as anything more elaborate. It would perhaps have been better to call for 'all lighting points' in a domestic premises to be RCD protected.

OK. Is there anything in a domestic electrical installation which produces light (other than neons/indicator lights) that you would not class as a luminaire?

I don't think there is, you have already covered the indicator exception, I would argue that anything that produces light in order to see by would be a luminaire

I am a little confused by the need for this, considering that lighting circuits on new domestic work have generally already been RCD protected since 2008, by virtue of requirements for concealed cables and luminaires (sorry!) in bathrooms, there will be a few things not caught by these, but what is the logic in requiring the surface clipped lighting circuit for the garage or loft to be RCD protected, or the SWA to the decorative lighting column next to the driveway.

I do not think this is the reason:

Another good reason for it is that a neutral/Earth fault could see the entire installation load current return through that 1.5mm^2/1mm^2 cable if the neutral connection to the meter is lost. I've seen it before and the cable was literally bubbling.

As there is no requirement for the RCD to break the neutral pole, a single pole RCBO meets the requirements, plus this would be a concern in none domestic premises as well

 

[securespark]

However, what I was asking for views about was the interpretation of the BS7671 definition.

I think logically, if 7671 defines a word or group of words, then one has to use that. Otherwise, one would have to use the dictionary definition.

 

[AndyPRK]

A high proportion of 'luminaires' are Class II, hence nothing earthed in the vicinity to touch - so an RCD would rarely help (unless the person somehow had a path to earth from themselves which was under ~7.7kΩ). Similarly, a high proportion of lampholders (whether in pendants or other light fittings are plastic - so, again, an RCD would not help (with same caveat).

Kind Regards, John

Don't you use a metal ladder or metal scaffold to change your chandler lamps John?

p.s The word luminaires isn't new to me

 

[JohnW2]

I'll agree with you only as far as that I do think its a rather pointless term, but it is clear that it was intended to cover pendants and batten fittings as well as anything more elaborate. ..... I would argue that anything that produces light in order to see by would be a luminaire

That''s obviously a view, but I have to wonder in what sense pendants and batten fittings (and some other things) "distributes, filters or transforms the light transmitted from one or more lamps".

I am a little confused by the need for this, considering that lighting circuits on new domestic work have generally already been RCD protected since 2008, by virtue of requirements for concealed cables and luminaires (sorry!) in bathrooms, there will be a few things not caught by these ...

True, but I suppose if 'they' have decided that the light fittings need to be RCD protected, they want that to still be the case even if (rarely) the light is not in a bathroom and the circuit's cable does not itself require RCD protection.

Kind Regards, John

 

[JohnW2]

I think logically, if 7671 defines a word or group of words, then one has to use that.

Quite so - so do I take it that you believe that, say, a pendant or batten lampholder (and other things), amongst other things "distributes, filters or transforms the light transmitted from one or more lamps"?

Kind Regards, John

 

[JohnW2]

Don't you use a metal ladder or metal scaffold to change your chandler lamps John?

For some I have to, yes (although I have nothing that I would call a chandelier - dangling things with three candle lamps/bulbs are the closest I get to that).

However, it would be extraordinarily unlikely that (indoors) the path to earth through a metal ladder would be low enough for anything remotely like 30mA to flow through a person to earth through it. With typical floor construction, floor coverings and footware, the resistance to earth is so high that (don't try it!), one will often not even feel anything if one touches 230V whilst standing on the floor (or on a metal ladder standing on the floor). The same would probably even be true with bare feet and no floor coverings - at least on a (dry) suspended wooden floor.

Hence, as I said, I don't think an RCD would be of any help unless there was something explicitly earthed in (or in the immediate vicinity of) the light fitting - which, as I said, in terms of the big picture is probably relatively uncommon.

Kind Regards, John

 

[rsgaz]

chandler lamp

What's a Chandler lamp Andy?!

 

[securespark]

Quite so - so do I take it that you believe that, say, a pendant or batten lampholder (and other things), amongst other things "distributes, filters or transforms the light transmitted from one or more lamps"?

Where is that quote from?

(and other things), amongst other things

Not sure what this means!!

 

[JohnW2]

Where is that quote from?

It's the first part of the BS7671 definition of a 'luminaire' (it goes on to mention other things a 'luminaire' might include).

Not sure what this means!!

It was rather confusing wording! I meant that (a) I was talking about "pendants and batten lampholders (and [probably] other things" and that (b) amongst other things, the BS7671 definition of a luminaire required the bit that I quoted. Is that clearer?

Kind Regards, John

 

[DetlefSchmitz]

a pendant or batten lampholder... "distributes... the light transmitted from one or more lamps"?

I think you are being more than usually picky about the wording. Starting from the position that we know what they are trying to say; a pendant holds the lamp in a position where it is able to distribute light. You may well be able to come up with a better form of words, but I don't think that anyone really is unable to follow what is intended.
The other business about indicators is also specious, but again I'm sure you can propose another form of words that put the required point across: that a luminaire is intended to distribute light for the purpose of lighting a space, to assist seeing things.
I'm looking forward to your wording. I know how difficult it is to agree on wording in a committee. One is always criticised for being pedantic.

 

[securespark]

One is always criticised for being pedantic.

I know how that feels! I don't mean you guys!

MOD: What has the latter part of this thread got to do with the OP? As usual if you want to continue an off thread topic, feel free to do so in a new thread.

 

[JohnW2]

I think you are being more than usually picky about the wording. Starting from the position that we know what they are trying to say; a pendant holds the lamp in a position where it is able to distribute light. You may well be able to come up with a better form of words, but I don't think that anyone really is unable to follow what is intended.

Maybe, but I think it is really 'them', rather than me, who is being 'picky/pedantic ...

I'm looking forward to your wording. I know how difficult it is to agree on wording in a committee. One is always criticised for being pedantic.

How about "A light fitting" (I can't see how anyone can criticise that for being pedantic).

If that's what they meant (which is what everyone here seems to think) why not just say so, without all the attempt at 'detail' ('pedantic', perhaps?) about "distributing, filtering or transforming the light transmitted from one or more lamps" etc. ?

Kind Regards, John

MOD: Which part of the warning above did you not understand?

 

[securespark]

.

 

[Belle427]

Didn’t realise I’d started world war 3!
Anyhoo, I’m thinking of using one of these, very good value and I used one before in a garage without issue.
Anyone had any issues with contactum gear?

https://www.tlc-direct.co.uk/Main_Index/Consumer_Units_Index/CP_Range_Main_Switch/index.html