Embedding cables out of CU

[vargen]

I've moved the cut-out and CU to a corner wall cupboard in my (being) renovated kitchen.

There will be 15 cables out of the top of the CU, running to the brick wall closing the open end of the corner cupboard. They then need to go up to the ceiling for distribution. I would like to embed the cables for the short run up to the ceiling rather than run them in PVC conduit in the corner above the wall cupboard. The wall in which the cables would be embedded is intended to be rendered, although it could as easily be plastered.

I can't fit 15 cables under standard capping within 150mm of the corner, although I could get a piece of 125mm wide capping custom pressed, which should do the trick. Is this a good plan, and is it OK for the bare cables just to run into the wall inside the cupboard from the CU or should they be in PVC conduit?

 

[sparkybird]

First off, I hope you got your supplier to move the cutout - it belongs to them and shouldn't be touched by the likes of us.

Second, cables can run in 'safe zones' ie in a zone horizontallly or vertically from any accessory, such as a fuse board, so if they are exiting the top of your fuse board straight up, then they should be in the zone and can be concealed. However, as many people aren't aware of this, the new wiring regulations helpfully (!) insists that all cables concealed in this was must be RCD protected.

 

[vargen]

Yep, EDF moved the cut-out and the meter board for me - really nice, helpful guys. Wouldn't really want to mess with that myself! Spark fixed a new 17th CU (with RCDs) and connected up a temp ring and lights until I get the new cicuits to first fix, then he'll connect up and test.

I know about the safe zones and will be well within the prescribed 150mm out from the corner. The question is how to protect the 15 cables chased into the wall? As I said 15 cables won't fit into standard sized capping within 150mm - there just isn't room.

Would it be alright to (sand & cement) render over the cables without protection, or should I get some wider capping custom pressed at my friendly local engineering company? I know old lime plaster ate the PVC sheathing, but what effect would cement have on it, if any?

 

[fubox]

cables will be fine as long as they are 30ma rcd protected

simple as that

 

[RF Lighting]

I don't understand the post above.

As has been said, you should keep the cables in a safe zone.
The use of RCDs does NOT allow you to run cables outside of the safe zones.


As for capping, you could use 2" capping and put 4 cables in each piece.

You can run it up the wall side by side with each other.

You could also as an aletrnative flush in some round or oval conduit.

You do not have to use any capping etc., but it is good practice to do so, and may come in useful in the future.

 

[vargen]

15 cables would require 4 sets of 2" capping with 4 cables in each. That's 8". Two of the cables are for oven + hob and shower; one is 1.5mm for lighting and the rest are 2.5mm. 150mm is only 6".

That's the problem - 15 cables won't fit WITHIN THE SAFE ZONE in standard capping!

 

[RF Lighting]

Why can't the cables go straight upto the ceiling from the fuse box?

 

[Taylortwocities]

I hate that 150mm rule. Electricians are the only peope who know it exists.

I would certainly not run cable up a corner in a kitchen, that's just where the fitter will bang in th supports for his wall cupboards.

150mm down from the ceiling is just as bad. Spot on for support nails for coving in my experience.

Am I being EXTRA grumpy tonight?

 

[333rocky333]

And drawing pins for the christmas decorations

 

[skenk]

Read Sparkybird's post. Directly above the CU is a safe zone, regardless of whether or not it's 150mm from the corner.

 

[vargen]

Can't go straight up from CU to the ceiling without using surface mounted PVC - CU is mounted on a fireshield plasterboard partition which closes a service shaft and I don't want to use visible PVC or penetrate the partition. There are pipes running up the shaft behind the partition and space is very restricted between them.

Cables really need to run across the top of the CU (inside the corner wall cupboard CU is housed in) into the returning brick wall (open end of corner cupboard is against this brick wall) and then up to the ceiling.

No problem with coving - not having any. No problem to support wall cupboard - 38mm plywood already behind plasterboard for that purpose, and I'm fitting the kitchen.

Looks like I'll have to get some capping custom pressed. If it's 150mm wide and 25mm deep, there should be plenty of room for the cables. I can run the cables across the CU in PVC (it won't be visible outside the corner cupboard) and fan them out into the capping in the brick wall.

 

[ban-all-sheds]

Capping doesn't provide sufficient mechanical protection for you to run cables outside the zones and less than 50mm deep anyway...

 

[pbar]

And drawing pins for the christmas decorations

Surely no buried cables should be within drawing pin reach?

 

[ricicle]

And drawing pins for the christmas decorations

Surely no buried cables should be within drawing pin reach?

You havn't been about much then.........

 

[pbar]

And drawing pins for the christmas decorations

Surely no buried cables should be within drawing pin reach?

You havn't been about much then.........

That's just plain scary.