Intermediate switches

[Risteard]

It is more desirable to wire multiway switches with 3C&E due to the reduced RFI this method creates.

I don't deny that that is a benefit. However it would still be technically better to use a twin brown and insulated and sheathed single brown instead of remarking conductors. Indeed BS7671 states a preference for conductors being identifiable throughout their length.

 

[JohnW2]

I don't deny that that is a benefit. However it would still be technically better to use a twin brown and insulated and sheathed single brown instead of remarking conductors.

That could be argued - indeed, 'triple brown', if it existed, would be even better from that point of view.

However, the important thing, functionally (i.e. in terms of reduction of unwanted radiation from cables), is that L&N conductors should be run in close proximity, all the way from the circuit origin to the load - something which, at least in England (and probably most/all of the UK), seemed often not to be done with the 'traditional' method of wiring.

Kind Regards, John

 

[ban-all-sheds]

With n-way switching, where n>1, what wiring method would see L&N conductors run in close proximity all the way from the circuit origin to the load?

 

[ban-all-sheds]

Indeed BS7671 states a preference for conductors being identifiable throughout their length.

BS 7671 also says, in Appendix 7:

4 Intermediate and two-way switch wires in a new installation or an addition or alteration to an existing installation

Where a three-core cable with cores coloured brown, black and grey is used as switch wires, all three conductors being line conductors, the black and grey conductors should be marked brown or L at their terminations.​

It does not, there, express a preference for the use of cable(s) where all the conductors are brown.

 

[JohnW2]

In terms of the traditional method of 2-way switch wiring ....

In the case of the 'conversion' method, there's essentially the same argument, other than that, in some of the cables, it is two Ls (with current travelling 'in opposite directions'), rather than L&N, which ideally should be in close proximity...

... but, of course, anyone who understands the circuits would already have known all that.

 

[ban-all-sheds]

In terms of the traditional method of 2-way switch wiring ....

Explain "traditional" in the context of light switch wiring.

 

[Risteard]

BS 7671 also says, in Appendix 7:

4 Intermediate and two-way switch wires in a new installation or an addition or alteration to an existing installation

Where a three-core cable with cores coloured brown, black and grey is used as switch wires, all three conductors being line conductors, the black and grey conductors should be marked brown or L at their terminations.​

It does not, there, express a preference for the use of cable(s) where all the conductors are brown.

It does in the actual Regulations. Not sure what the relevance of an Informative Appendix is.

 

[Idrisdraig]

Just asked my wholesaler and he said no they do not

That seems to answer my question. Thanks.

 

[John D v2.0]

Indeed BS7671 states a preference for conductors being identifiable throughout their length.

Identifiable as l or n, indeed, but I don't feel like that's always helpful from a practical point of view.
Yes for a normal switch drop for a loop at the ceiling, the browns are the same, and twin brown and single would be fine, but for a triple brown it wouldn't be as easy.
Not a big issue and not relevant to the regs, but worth mentioning

 

[ban-all-sheds]

It does in the actual Regulations. Not sure what the relevance of an Informative Appendix is.

The relevance is that it shows the level of fatuousness of your suggestion that it really would be preferable to mess about running a DI single alongside twin and earth just to keep the use of only one phase colour.

 

[ban-all-sheds]

and twin brown and single would be fine

Without extra work during installation, 50% of the time you'd have to swap L1 & L2 (or L2/L3) at one switch to get the usually-required symmetry.

 

[Risteard]

The relevance is that it shows the level of fatuousness of your suggestion that it really would be preferable to mess about running a DI single alongside twin and earth just to keep the use of only one phase colour.

What is a DI cable?

 

[JohnW2]

Sigh. The Inquisition is getting everywhere.

 

[Taylortwocities]

Possibly he means I & S.

 

[JohnW2]

Possibly he means I & S.

That possibility never occurred to me

Kind Regards, John