Switched Live sleeving when looping at switch

[JohnW2]

... here’s my summary. .... When looping at switch, the brown wire in L1 is the switched live and since it is brown, it doesn’t require (regs) any additional identification.

Correct.

That said, some may want to use their personal identification method for their own convenience. Yellow was being suggested ...

I think it was probably me who started the discussion about 'personal identification methods' so, just in case I wasn't clear, it is something I would very rarely do (and probably never for a simple feed to a single light switch) - I just explained the convention/habit I personally use on the rare occasions I feel it desirable (for my own purposes) to identify a conductor as a switched-live.

...and in the same vain brown over sleeving can be used as I suggested? May not be very clear as it’s brown on brown but clearly the oversleeving would be much smaller.

I personally would not do that. Quite apart from the fact that, as you acknowledge, 'brown on brown' might not even be noticed, I think there would be an appreciable risk that someone else (stupidly) guessing what it meant could well come to the incorrect conclusion. If I were 'forced to guess', I would probably say that 'adding more brown to brown' was probably intended to underline the fact that "this REALLY IS the line/live conductor" (i.e. the permanent L, not switched L).

Blue over sleeving cannot be used as it suggests that this is neutral.

Correct.

As suggested by these “personal” methods, there is a risk of incorrect identification and hence, should always test the wires if working on a unknown system.

Indeed. As I've said, in the absence of anything other than 'personal' conventions' for such identification, no-one else could (should) guess the meaning and not confirm by tresting!

Kind Regards, John

 

[SimonH2]

Question ...
Is the switched live a "power" conductor, or coukd it be consideted as a control/signalling conductor ?
If the latter, then the table in (from memory) 514 allows a range of colours - inckuding John's yellow

 

[SimonH2]

Question ...
Is the switched live a "power" conductor, or coukd it be consideted as a control/signalling conductor ?
If the latter, then the table in (from memory) 514 allows a range of colours - inckuding John's yellow

 

[JohnW2]

Question ... Is the switched live a "power" conductor, or coukd it be consideted as a control/signalling conductor ? If the latter, then the table in (from memory) 514 allows a range of colours - inckuding John's yellow

It must be Friday night

In the context we are talking about, it is surely cannot be considered to be a control/signalling conductor, since it carries the full current of the load?

Indeed, if we took that argument to its (ridiculous) logical conclusion, then every conductor could become a 'control;/signally conductor', since every conductor is switched by something (even if only the Main Switch of a CU)!!!

Kind Regards, John

 

[Risteard]

There's no getting away from the fact that yellow is verboten.

 

[JohnW2]

There's no getting away from the fact that yellow is verboten.

If you believe that 'a small ring of yellow' on a clearly brown conductor is actually trying to 'identify' the conductor (in the BS7671 sense, even though yellow has no meaning in that context), then ....

1... totally sleeve all of the exposed brown conductor with yellow sleeving, so that all that can be seen is yellow. That has no BS7671 meaning for identification of a 'power conductor', hence is not compliant with BS7671.

2... now put a small bit of brown sleeving over that yellow-sleeved conductor (leaving plenty of the yellow visible). Given your argument, you presumably accept that what one then has ('identification' then being by the bit of brown 'over-sleeving') is complaint with BS7671 as a correctly-identified line conductor?

 

[Risteard]

I'm not sure of your point. The purpose of the sleeving is to mark the function as other than what the insulation of the cable core would otherwise imply. Therefore brown over a yellow core clearly (and expressly in BS7671) means that it is a line/phase conductor of a single phase supply (or L1 of a polyphase supply).

By putting yellow sleeving over the core you are stating that "this conductor is not what a brown conductor is - it is what a yellow conductor is". It having no meaning makes it all the more confusing, but certainly doesn't make it acceptable.

 

[SUNRAY]

I'm not sure of your point. The purpose of the sleeving is to mark the function as other than what the insulation of the cable core would otherwise imply. Therefore brown over a yellow core clearly (and expressly in BS7671) means that it is a line/phase conductor of a single phase supply (or L1 of a polyphase supply).

By putting yellow sleeving over the core you are stating that "this conductor is not what a brown conductor is - it is what a yellow conductor is". It having no meaning makes it all the more confusing, but certainly doesn't make it acceptable.

But If you placed a lable on the CU: 'Lighting circuits contain yellow markers on switched lives' or something similar then the variation is documented and within regs.

 

[SUNRAY]

I'm not sure of your point. The purpose of the sleeving is to mark the function as other than what the insulation of the cable core would otherwise imply. Therefore brown over a yellow core clearly (and expressly in BS7671) means that it is a line/phase conductor of a single phase supply (or L1 of a polyphase supply).

By putting yellow sleeving over the core you are stating that "this conductor is not what a brown conductor is - it is what a yellow conductor is". It having no meaning makes it all the more confusing, but certainly doesn't make it acceptable.

But If you placed a lable on the CU: 'Lighting circuits contain yellow markers on switched lives' or something similar then the variation is documented and within regs.

 

[SimonH2]

In the context we are talking about, it is surely cannot be considered to be a control/signalling conductor, since it carries the full current of the load?

Many control circuits carry the full load current.

Indeed, if we took that argument to its (ridiculous) logical conclusion, then every conductor could become a 'control;/signally conductor', since every conductor is switched by something (even if only the Main Switch of a CU)!!!

There's a difference between facilities for isolation, and switching which is part of the function of the circuit.
Take the wiring in a heating circuit. At church, the time clock and stats switch the full current of the pump and boiler. So are we suggesting that because all the switched wires carry the full load that they aren't control circuits ?

 

[bernardgreen]

So are we suggesting that because all the switched wires carry the full load that they aren't control circuits ?

They are not controlling anything, but the current through them is being controlled by the various control devices.

A control wire feeds control currents / voltages / waveforms to devices which control the load current.

 

[JohnW2]

I'm not sure of your point. The purpose of the sleeving is to mark the function as other than what the insulation of the cable core would otherwise imply.

Indeed so.

....Therefore brown over a yellow core clearly (and expressly in BS7671) means that it is a line/phase conductor of a single phase supply (or L1 of a polyphase supply).

Again - and that is 'my point' of which you are not sure. As you say, brown over yellow would (as I said) correctly identify the conductor as a "line/phase conductor of a single phase supply" - so no compliance issues. HOWEVER, the fact that the brown was over yellow would (if I used that convention) have an additional meaning to me - namely that it was being used as a 'switched live'.he more confusing, but certainly doesn't make it acceptable.[/QUOTE]

 

[SUNRAY]

They are not controlling anything, but the current through them is being controlled by the various control devices.

A control wire feeds control currents / voltages / waveforms to devices which control the load current.

I think you need to speak to 'controls engineers' to find out what work they do and are expected to do. They are constantly having to correct the work done by electricians.

 

[JohnW2]

Many control circuits carry the full load current.

Like bernard, I would not, and so not, regard that as a 'control circuit'.

There's a difference between facilities for isolation, and switching which is part of the function of the circuit.

Fair enough, but we're talking about 'functional switching' (light switch).

Take the wiring in a heating circuit. At church, the time clock and stats switch the full current of the pump and boiler. So are we suggesting that because all the switched wires carry the full load that they aren't control circuits ?

Yes, I am - since, as I said, otherwise one would call any circuit with a functional switch (whether manual, timeswitch, thermostat or whatever), hence almost any circuit, a !"control circuit".

If you're church's pump and boiler with switched on an off by a relay/contactor [the coil of which was 'controlled' by timeswitch/thermostat/whatever] then I would call (only) the 'circuit' supplying the relay/contactor coil (albeit not 'a circuit' per BS7671 definition), but would not use that description for the circuit which was 'functionally switched' by the relay/contactor contacts.

Kind Regards, John

 

[bernardgreen]

I think you need to speak to 'controls engineers' to find out what work they do and are expected to do.

Then I would need to talk to the person I was from 1984 till 1994,

They are constantly having to correct the work done by electricians.

To an extent I can agree with that, electricians without adequate guidance / wiring schematics can make errors and ommissions