Mixing two sets of colours in wiring
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Mixing two sets of colours in wiring

by spaceman » Sat Jul 04, 2009 2:10 pm

Hi all!

I'm about to do some rewiring in my house and prepare everything before I bring in an electrician to install a new consumer unit (I still have an old style unit and fuses) and connect everything up.

I bought a Siemens Logo unit to add some simple automation to the house. I just need to lay down cables from the light points to the consumer unit. the cable are of course the new type with brown and blue colours, but all the circuits in the house are red and black.

Is it ok to mix both sets of colours or will I have to replace all the old red and black cables as well?

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by rosebery » Sat Jul 04, 2009 7:08 pm

Its OK for an installation to have wiring colours to two editions of BS 7671 PROVIDED that there is the appropriate sticker on or adjacent to the Consumer Unit which says so.

Whether your electrician is happy for you to do some preliminary work is a matter for him.


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by kbrownie » Sun Jul 05, 2009 7:43 pm

It's okay to have the new and old core colours on the same system providing there is a notice at the CU stating that.
I would suggest you have an Insulation Resistance Test on the old circuit, to assure it is still in a healthy condition prior to any thoughts of keeping it or rewire.
Please take a look at Part P on projects page, regarding notifiable work.

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