New three-phase wiring colours

[Startinez]

Hi all.

I'm starting a new project at work and part of it is installing SPDs onto D.B.s in telecommunication installations. All of the current wiring in the boards is from before the colour harmonisation and so obviously is R,Y,B for three phase.

Obviously the regs state that it should be installed in the new colours of Br, Bl, Grey with blue as the neutral - but in this instance isn't that really dangerous? I mean a sticker saying the old wired to two versions of BS7671 is great and all and will probably cover my back, but is it really actually safe to do that?

Also finally, I've only been provided with Br & Blue cable, but I'm thinking it's not really very good practice (if even acceptable?) to have L1, L2, & L3 in brown cable even if they are labelled specifically as each line?

Appreciate the help.

 

[Andy78]

You are listed as a trainee. Are you doing this work under supervision ?

 

[westward10]

Using all brown is fine with blue as neutral. Not dangerous at all you are putting in place a notice and anyone working on it in the future should have sufficient competence.

 

[Andy78]

Using all brown is fine with blue as neutral. Not dangerous at all you are putting in place a notice and anyone working on it in the future should have sufficient competence.

As long as the brown conductors are marked at all terminations to show which phase they are designated to.

 

[Des 56]

Also finally, I've only been provided with Br & Blue cable, but I'm thinking it's not really very good practice (if even acceptable?) to have L1, L2, & L3 in brown cable even if they are labelled specifically as each line?

The phase colour of single phase circuit/supply derived from a 3 phase installation should be Brown
If you use Brown cable from each phase,it need have no other phase colour to identify which particular phase it is derived from
If you use Black or Grey for single phase it should be sleeved Brown (and preferably be brown throughout its length)
The 3 phase colours were permitted prior to the colour change,but it can cause confusion with the present silly colours in an installation using the older colours

Edit to add,if you want to designate which phase they are from,you can use number labeling

 

[westward10]

Also finally, I've only been provided with Br & Blue cable, but I'm thinking it's not really very good practice (if even acceptable?) to have L1, L2, & L3 in brown cable even if they are labelled specifically as each line?

The phase colour of single phase circuit/supply derived from a 3 phase installation should be Brown
If you use Brown cable from each phase,it need have no other phase colour to identify which particular phase it is derived from
If you use Black or Grey for single phase it should be sleeved Brown (and preferably be brown throughout its length)
The 3 phase colours were permitted prior to the colour change,but it can cause confusion with the present silly colours in an installation using the older colours

Edit to add,if you want to designate which phase they are from,you can use number labeling

I tend to agree with not identifying three browns on a three phase circuit but Table 51 doesn't actually give that option. Lines 2 and 3 should be tagged black and grey or numbered L2 and L3.

 

[Startinez]

You are listed as a trainee. Are you doing this work under supervision ?

I am technically a trainee but I have my 17th Ed certification (as well as a few others) and that is all that is actually required to work with electrics for telecoms companies. It's a very easy installation, literally isolating the D.B., taking a feed from the three phase MCBs (C63s) and the neutral and earth bars into the SPD, and there isn't even any testing involved as it has indication lights to show fully working, faulty etc. It's a Furse ESP 415, if you care to have a look at it.

Using all brown is fine with blue as neutral. Not dangerous at all you are putting in place a notice and anyone working on it in the future should have sufficient competence.

Yeah, this is my thoughts but that's assuming that only competent people will do so. I guess it's not my fault if they do, but I still don't like the thought of it regardless.

As long as the brown conductors are marked at all terminations to show which phase they are designated to.

I would probably do that for peace of mind as I have a label maker for the rest of the work that I'm doing anyway.

Appreciate the advice guys.

 

[Andy78]

I am technically a trainee but I have my 17th Ed certification (as well as a few others) and that is all that is actually required to work with electrics for telecoms companies. It's a very easy installation, literally isolating the D.B., taking a feed from the three phase MCBs (C63s) and the neutral and earth bars into the SPD, and there isn't even any testing involved as it has indication lights to show fully working, faulty etc. It's a Furse ESP 415, if you care to have a look at it.

Yeah, this is my thoughts but that's assuming that only competent people will do so. I guess it's not my fault if they do, but I still don't like the thought of it regardless.

I would probably do that for peace of mind as I have a label maker for the rest of the work that I'm doing anyway.

Appreciate the advice guys.

All alterations, additions, and new circuits must be tested and a certificate produced. This must be carried out by a person competent and experienced enough for the task.

The marking of the phases would not be for peace of mind, but for compliance with the wiring regulations.

 

[HandySparks]

The phase colour of single phase circuit/supply derived from a 3 phase installation should be Brown...

But this is a three phase circuit to the SPD isn't it?

 

[Des 56]

I apologise for my answer,I skim read the question and got the content all to pot
My post makes little if any sense when applied to the question that "was" asked

 

[Risteard]

The 3 phase colours were permitted prior to the colour change

No they weren't (ever) for final circuits. And it is a considerable amount of time since they were allowed for single phase distribution circuits. (Perhaps 15th Edition or possibly earlier?)

 

[Risteard]

I mean a sticker saying the old wired to two versions of BS7671 is great and all and will probably cover my back, but is it really actually safe to do that?

Any interface between pre-harmonised and harmonised colours must also have alphanumeric identification in a three-phase system so yes, it is safe so long as whoever is working on the system bothers to identify the conductors as instructed by the warning label!