extending a kitchen ring with trunking

[laticsman]

Hi guys I am looking to extend my sons kitchen only 2 sockets at the moment. The first big problem is that the kitchen is below the bathroom, problem is the last people had a tiled floor put in so no access to floorboards. What I was hoping to do is run some trunking around the wall,I will crimp one of the ring main cables in the back of the socket and do the ring then return to it. I was going to install one of the 4way control points, the ones that have dishwasher/oven/cookerhood/microwave etc, I will loop from switch to switch to keep the ring intact. But the big if is can I run the trunking around, a new fitted kitchen will then be fitted afterwards. Also does the 4way controller need to be above the worktops because I want to put in chrome sockets and there are none available in chrome?

 

[PrenticeBoyofDerry]

I think first you should know about the regulations concerning, kitchens and electrical installations or addition/extensions of existing circuits.
Search through this link;
//www.diynot.com/wiki/electrics:part_p

 

[wingcoax]

If that's the only option then you will be ok, but as PBD says you need covering with the LABC and a registered sparky.

 

[laticsman]

thanks guys for that but am I still ok to put the 4way "controller" below the worktop height? I will get a leccy to check it out afterwards

 

[wingcoax]

You are much better putting the "controller" as you call it above the worktop for ease of access. This is in case of "emergency switch off" being required.

 

[flameport]

Getting someone to check it afterwards is no use, LABC must be notified before the work is started.

Those '4 way control points' are not compliant on a ring circuit either, since they result in most of the load on the ring being concentrated at a single point. Unless it is installed at the centre of the ring, one of the cables will probably be overloaded. Even at the centre of the ring it's still a poor design.

 

[laticsman]

Thanks wingcoax very valid point and will do so, but flampoint if they are not compliant then why did they wholesalers recommend this was the best way. I thought having everything in one place for isolation purposes was a better thing to do? There would be some diversity as the dishwasher would only be used maybe every other day or so, its a 13amp oven and a built in microwave 3/4 amp and a cooker hood 1amp or so. The most they would perhaps put in the sockets is a toaster or kettle. Do you still think this is a bad idea.

 

[flameport]

if they are not compliant then why did they wholesalers recommend this was the best way.

Wholesalers are in business to sell things. Most of them have little or no knowledge of how or where their products should be used, and really couldn't care less what you do with them.
Same applies to most retailers and all DIY sheds.

Whether or not the cables are overloaded will depend on what is connected, how/when it is used and the length of the two cables between the switches and the consumer unit.

If this is a standard ring with 2.5/1.5 flat cables, each cable is rated to around 20A. This is fine with loads at various points along the ring.
However with the switch panel, an oven and dishwasher used simultaneously will put a 20+ amp load at that single point. Someone puts the kettle on, which will be another 10A.
Total current now 30A.

If the ring was 10 metres long, and the 30A load was 2m from the consumer unit, the load would be 24 amps in one cable and 6 in the other. This is overloading the cable.
If all of the 30A load was at the centre, each cable would carry 15A - well below the cable rating.

While this arrangement can be made to work, I wouldn't install it on a ring.
If those multiple switch panels must be used, they should be connected to one or more radial circuits, with cables sized appropriately.
Then there is the issue of what the rating of the switch terminals is, and if various sized cables will actually fit into them.

 

[laticsman]

Ok fair point what about fitting fused spares instead then would that be ok? the reason I looked at this is that I have them in my house but admittingly less load fridge/freezer/cookerhood/washing machine and been in 18 months ok. I bought a new house with it installed this way so presumed it would be ok thinking that diversity would be alright.

 

[ban-all-sheds]

If you want a grid switch, put it on a radial.

 

[laticsman]

Thanks guys for the advice chosen to go for fused spurs instead, seems the best way after all.