Wiring a JB like the pros

[AdamW]

I am doing some wiring for a flat my parents are buying to let out. I am desparate to get in there to find out what they want so I can buy all the cable in red and black. I have a bad notion that by the time they get possession of the keys it will be too late and I will have a weekend of sleeving cables in "gopping" brown!

Do you think they paid any thought to colour blindness when they decided the new colours? I know that some people are completely red blind (my great uncle for instance, couldn't tell if those sometimes-on traffic lights were switched off or on red!) so red/black is probably pretty difficult for them.

 

[securespark]

So if R+B is difficult for CB people, why do you want to buy all R+B?

Or have I missed something?.......

 

[AdamW]

Well, I am not CB myself! What I mean is, I wonder if one of the considerations they made when deciding on new colours (back when they did the flex I guess) was colour blind DIYers.

I want to get R+B so I can do the necessary wiring in this flat with the minimum of effort. If it gets too late and I can only buy Blue and Brown then I will have to go around with the sleeving and do every socket, lightswitch, ceiling rose, CCU, FCU and I suppose even the CU.

I bet that very few people will take this much effort to ensure uniform colours throughout their installation. I fear that there are going to be many houses that end up with a mismatch of colours all over the place!

 

[dingbat]

I want to get R+B so I can do the necessary wiring in this flat with the minimum of effort. If it gets too late and I can only buy Blue and Brown then I will have to go around with the sleeving and do every socket, lightswitch, ceiling rose, CCU, FCU and I suppose even the CU.

There's no requirement to retro-sleeve existing wiring. If you have to use brown & blue for new circuits/additions then you can buy warning labels for the CU which state that there is a mix of old and harmonised colours. If you are going to mix the two schemes in any terminations (sockets, switches, etc) you should sleeve all cables up in one scheme. E.g. if you add a spur from a R+B socket using B+B you should identify all like conductors with the same colour, using sleeving to make the matches.

 

[plugwash]

i'm sure the iee supplement i read said that marking at the join was not needed on single phase

and on 3 phase lettered markers not sleeving was the reccomended method

 

[dingbat]

You're right, Plug. I was recalling what I read in The IEE Wiring Matters - Issue 14, Spring 2004

"What is required is that, except where there is no possibility of confusion, unambiguous marking shall be provided at the interface between conductors..."

But in the new BS:7671, Appendix 7 it does indeed state:

"An alteration or an addition made to a single phase installation need not be marked at the interface provided that:

i) the old cables are correctly indentified by the colour red for phase and black for neutral, and
ii) the new cables are correctly identified by the colour brown for phase and blue for neutral."

So there we go.

 

[AdamW]

You see, this is why a forum is so good. If you read one man's word on his website, for all you know he is talking absolute balderdash. Glad I brought this one up then!

The heat is off. Phew.