UKC

One for the electricians on here, I know there are a few.
I'm looking to add a plug to an existing radial circuit in a bedroom. As far as I can see from reading the "official document" that I am ok with as they put it "Adding socket-outlets and fused spurs to an existing ring or radial circuit" so long as it's not in a special location and that the circuit is protected by a suitable over-current protection device.

My question is:
I will need to add a small amount of new cable into the circuit between the new plug and the next plug on the circuit to give myself enough cable to make all the connections. The circuit I'm adding to is wired in red/black 2.5 mm twin and earth and I have a substantial amount of new red/black cable, can I use this cable or do I have to use new brown/blue?

The way I see it is that it will be more confusing to anyone looking at it if I have a mix of the two types in the same sockets, and I've been told that this is generally not ideal. Also, I've got the cable here so may as well use it if I can.

Any advice appreciated,
Thanks,
Gethin

In reply to gethin_allen:
You can use any cable you like so long as it has good insulation and can carry the current it is fused at. Colour is irrelevant. If you want to stick to regs then brown/blue is the way to go. If you are concerned future house owners will go messing about with it then stick to regs. Also be sure that you are dealing with a radial circuit not a spur off a ring. You cannot spur off a spur. Not best practice to spur off a radial either.

In reply to gethin_allen:


20A I hope!

In reply to gethin_allen:

one thing depending on the answers you choose to go with you can use the R/B you have BUT if you want to identified as new colour you can sleeve or tape in the colour you require. if you go brown blue you should note this on the cu.

In reply to Lusk:


Yes, Both the old plug circuits are on 20A MCBs with the new ring in the kitchen on a 32A and everything other than the lights are on a 30 mA RCD

In reply to Name Changed 34:

>...if you want to identified as new colour you can sleeve or tape in the colour you require..."
Good idea, like when you've got light switches where the neutral is really live if the switch is on.

"...if you go brown blue you should note this on the cu."

There is already a big yellow sticker on the consumer unit warning of this.

In reply to gethin_allen:

not quite the 2 cores at the light sw should be a live and a switched live no neutral

but yes you can identify them in the same way and be legal

In reply to Cheese Monkey:
"... If you are concerned future house owners will go messing about with it then stick to regs..."

This is my real concern, If i was set on living here for ever then I'd be happy to do it however I like as long as it's safe but when I'm potentially looking at selling in a year or so I have to be sure everything is totally to the book. Although I guess I'd have to have all the electrics safety checked before I sold it. Saying this, the checks done on the house before I bought it were so poor as to be a joke. There were obviously dangerous things that really should have been identified and they weren't even able to identify the size of cables correctly, stating in the report that a cable was 4 mm when it was actually 2.5.

"Also be sure that you are dealing with a radial circuit"
I'm quite certain, I've had all the floorboards up over the last few years. I prefer radial circuits over rings, they are so much simpler to check and find faults and you don't have the issue of potentially overloading a cable if there is a break in the terminal.

In reply to Name Changed 34:


Hmm,
All the lights I've got (unless there is a upstairs/downstairs switch) have a normal 1 mm red/black twin and earth with a bit of red tape on the black conductor to identify that it could actually be live. Is this right or is this something I should look into?

In reply to gethin_allen:
that's what you would expect . and is correct, the thing is the black core [marked red] is not in the neutral circuit it is in fact a dead live
the neutral runs direct [ish] to the light the pair at the sw are;;1 live to the sw, 2 live back up the wall to the light

you can buy twin Brown for sw drops or twin red as it was

hope it helps remember dead live on return to light when switched off

In reply to Name Changed 34:

That's what I meant, I just wasn't using the correct terms.
I've got so many historic pipes and wires in this house I was getting worried.
I found recently some thin lead gas pipes leading to the light fittings so I must have had gas lights at some point.
I've also found textile wrapped cables in metal conduits, cables with lead sheathing, cables with crumbly rubber insulation. All dead fortunately.
Thanks for the info.

In reply to gethin_allen:

All fun and games aint it. I found that our ring main was done with twin cable with a seperate earth wire, which was just bare stranded crap. To save 2p they hadn't bothered finishing the ring with the earth either, it went to every socket just not back to c/u from last socket.

Then found a socket in living room spurred off kitchen radial. Spur was taken 2" from c/u with a junction box added. Why the hell they didnt just put it onto a spare slot in c/u and add a mcb I dont know, would of been so much easier

In reply to Cheese Monkey:

when I stripped back the kitchen I found a length of 13A flex behind the lovely wood cladding feeding 2 double plugs. This worried me a bit as before this I'd had a fridge and toaster on the one double and a kettle on the other and in the morning I would often put the toaster and the kettle on together drawing about 4 kw + whatever the fridge was.

In reply to gethin_allen:

I'd use what cable you've got. (Why buy new when you already have some) Assuming it's the same size. IE 2.5 mm. It'll all match then and suit the OCDers amongst us.

You'll be fine.

In reply to gethin_allen:


I've had all that, all ripped out now over the years.

One last thing...you should really carry out an Insulation Resistance test on your new cable!
But I'm sure it'll be fine; if it is knackered, your RCD won't hold.

In reply to gethin_allen:

Definitely do not mix colours in an individual circuit - it would be a potentially lethal to people working on it in the future and if discovered could cause problems when selling the house. As noted by others the old colours (Black & Red) are permissible within existing installations and for minor modifications to existing circuits (new circuits must be to the new colours (Blue & Brown) and a suitable mixed colours warning notice used on the CU).