Wiring of new Consumer Unit

[Tipu Sattar]

I have completely rewired my house (The house had been stripped to the bare walls and joists). The only thing left to do is put in a new Consumer Unit and wire all the circuits to it. All the cables come into a cupboard under the staircase through the ceiling.

I am installing a surface mount MK sentry Consumer Unit. My question is how should I route all these cables into the Consumer Unit? Do they all have to be put into trunking and then fed into the top of the CU? Or is it better to chase channels and bury the cables and feed them into the CU from the back? There's a hell of a lot of cables there.

Any advice appreciated.

[Chris Oates]

Ugly wiring is not a hanging offence

most peeps clip them to the wall so that high current circuits go nearest the nearest the switch and lighting furthest away.

DO NOT cut wires to exact length - leave some slack somewhere

[usenet]

Yes, quite OK to fix to surface as long as there's no significant risk of damage. If there's brooms and things hanging in the cupboard close to the wiring it might be argued that they should be in trunking.

When I did my mother-in-law's I used some large (38mm x 25mm) mini-trunking and found it fairly easy to make a reasonably neat job.

All good advice.

[usenet]

The *wiring* goes in the trunking of course! :-)

[Dave Liquorice]

But might make the inspector look a bit harder at the installation.

The instructions for the CU should say that anyway. But trying to arrange the cables so they layout like that down the wall is probably a good idea. Personally I'd go for good sized truncking with lots of space around each cable or make the board that CU is attched to go right up to the ceiling an neatly clip the cables to that. What you don't want to do is squeeze them all together in a tight bundle, the ones in the middle might(*) get too hot...

(*) small might depends entirely on the loads, but the inspector might take a dim view of a tight bundle.

A good foot or so tucked up into the void and again the use of a duct or clipped to a board means things are easy to move about compared to being chased into the wall with bends etc. If you want to cover the clipped cables a couple of 1" battens and a sheet of light ply/hardboard will do, probably good from the physical protection POV anyway.

[Paul]

Not the mother in law?

Thats not what my IEE onsite guide says... ;-)

[Christian McArdle]

Whatever floats your boat. It is purely cosmetic, unless there is any chance of the cables getting snagged. If anything, surface mount cables are easier when alterations are made.

Christian.

[Dave Stanton]

Cable tray works well.You can use cable ties to anchor cables to the tray.

Dave

[Tipu Sattar]

Fantastic advice chaps. I've decided to surface mount them. Use 1" battens and a piece of ply to cover it. Of course, I'll leave plenty of slack. Dont really fancy the trunking method as it will involved quite a few of them as theres a fair few cricuits and dont want to bundle them into big trunking as things like heat generation etc concern me.

btw the cupboard is too small for any other use apart from housing gas/ elec meter and CU. So those worried about putting stuff like brooms or in laws in trunking should be rest assured....

[John Watson]

You can get some pretty big trunking - I've got some 75mmx75mm, and often use 50x50 for consumer unit cabling. I'm sure bigger sizes are available. It can look very neat if you cut it carfeully with a mitre saw.

Using trunking does of course change the "installation method" and reduces the current carrying capacity of the cables!

John