DIY Doctor UK DIY Forums

Hello there.

I'm extedending the garage and am taking the oppotunity to add in a new ring circuit to connect everything properly.

For the ring, I wil be running the 2 x 2.5mm cables in some conduit.
The maximum ring length will be about 25m.

Would it be safe to run a lighting cable (1mm) in the same conduit if it is coming from a different MCB ? The new lights are 4 x 18w battens

Notes:
There will be different points where sockets / lighting will be taken out and go back in. I would guess the first run where the cables will be next to each other would be no more than 5m.

The building work is continuing on to the kitchen shortly so new ring will be tested with part P with kitchen.

Many thanks!

You will not get 2 x 2.5 T&E cables along with a 1.5 T&E into a 20mm conduit, you will have to use singles as that is what conduit is designed for, not to mention you will have to use T boxes to drop down to each socket.
Even if you used T&E and surface clipped it, you should NEVER run another cable through the back box/patress. If you did, and when you need to change the back box/patress you will have to disconnect the lighting cable (in this case) to pull it out to change a box.

I would suggest you consult the person who is going to check it all (Part P) what they would be happy with. (After all, it will be their name on it, not yours.)

Thanks Mr.White ..

To expand on the situation, the garage has been extended to house a utility room as the small kitchen (which is falling apart) will be refitted in the next "few" months when the kitchen co (parts & labour are in stock yet) and my spark has returned from his long awaited holiday is available!! So its a big of a jigsaw with the work being carried out.

I had hoped to run the 2 x 2.5mm and a 1mm in the conduit and properly use the conduit junction boxes so I would not need to drop the 1mm lighting cable to the socket then divert the them to the switches / lights.

I'm OK with switching over to single wires, I can get the cable swapped...

My main concern was running the lighting cable right next to the ring main cable, I didnt know if this would cause any problems either with the regulations side (2 circuits in the same conduit) or "interfere" with each other ?

Many thanks

I have argued with other electricians over if to use conduit and singles or steel wired armour cable (SWA), there is no right or wrong, but to fit SWA is normally faster and easier than wrestling with a pipe bender, and with plastic conduit no more protection than using twin and earth.

Worked with Germans with some jobs, and they do some thing which to British electrician seems wrong, they free air on the bends.

However this may be the way forward, run twin and earth high in garage out of harms way, and just use a length of steel conduit for the drops.

There is a big difference in a garage to work in, and a garage to store a car, most garages with domestic property do not really need SWA or steel conduit.

On a bare wall twin and earth does not look good, although serviceable, I would use trunking just to make it look tidy.

Thanks Ericmark,

I'm making it look neat and keeping it safe / right for the regs when all the electrics are finished off. Typically its a British garage, with everything but a car :-)

So, after the comments below, I will use plastic conduit and inside it - I will have LEN 2.5mm (proper) singles for the ring main and will use 1mm twin&earth for the lighting. I will be running drop downs to the sockets without the lighting and vice-versa for the lights/switches.

It was just to make sure the 2 circuits would not interfere with each other ??

Also ....
Can you strip twin and earth and use the LN as singles ???
Just a thought - due to cost....
-note: I have not done this as I have bought 100m reels of singles ... ready for the kitchen !!

Thanks !!

It would cost you more in time and money to strip a T&E and you would still have to buy Earth. (T&E earth has no insulation, so you could not use it)
Do the job properly or not at all.

Thanks Mr.White.
The LEN singles have been purchased and pulled, I am keeping it as per book, however the point I was making was that buying 3x100m reel at aprox £90 is a more than T&E + Earth single (25m required for job) at £35 !