Kitchen Electrics

[cdh]

I have just completed a kitchen extension and now it needs re wiring.

Am i right in thinking that the kitchen sockets need to be on a separate circuit to the rest of the house.

Would the kitchen lighting circuit also have to be on a separate circuit to the rest of the house?

Finally, the washing machine and tumble dryer are being moved into the garage which is next to the kitchen. What circuit should these be on. (there are currently no sockets in the garage).

Thanks.

 

[securespark]

If you can, put in separate circuits. Or, you could put in a whole new board for the extension and new circuits and leave the old CU as it is.

This needs notifying.

 

[ban-all-sheds]

I have just completed a kitchen extension and now it needs re wiring.

First, and very important question, as it may be related directly to you ending up between a rock and a hard place with your LABC:

When you applied for Building Regulations approval, what did you say, or allow to be said on your behalf, or by default tacitly accept, would be the way that you would ensure that the electrical work would comply with Part P?

Am i right in thinking that the kitchen sockets need to be on a separate circuit to the rest of the house.

Would the kitchen lighting circuit also have to be on a separate circuit to the rest of the house?

Finally, the washing machine and tumble dryer are being moved into the garage which is next to the kitchen. What circuit should these be on. (there are currently no sockets in the garage).

OK.

Given those questions, please read this:

FOR DESIGN, CONSTRUCTION, INSPECTION & TESTING
I being the person responsible for the design, construction, inspection & testing of the electrical installation (as indicated by my signature below), particulars of which are described above, having exercised reasonable skill and care when carrying out the design, construction, inspection & testing hereby CERTIFY that the said work for which I have been responsible is to the best of my knowledge and belief in accordance with BS 7671:2008, amended to ............. (date) except for the departures, if any, detailed as follows:

Can you sign that?

If not, who do you think will?

 

[ericmark]

It does say in the 17th Edition (also known as BS7671:2008) that items fix over 2kW should have their own dedicated circuit. How we define fixed not sure but in real terms washing machine, tumble drier, dish washer, oven even if they do have wheels to be drawn of for maintenance are really fixed appliances.

Often when one installs a kitchen ring it is to cater for these sort of loads it does not really do what is said in having dedicated circuits but it does move to that direction. This is why people consider the kitchen needs it's own supply.

If we look at the items which should be in a kitchen which does not really include washing machine and tumble drier then with the cooker (hob and oven) on their own supply there is little need for anything else to have a dedicated supply. The dishwasher may be should but although it is over 2kW the time it takes to heat water is not very long as very little water in them so not really that much of a problem.

I have all ways thought the electrics should be detailed before plans are submitted mainly as any objections want sorting before any wires are pulled in not after first inspection.

The big thing as far as you are concerned is the garage supply. The tumble drier can really draw current for an extended time and so should have it's own circuit. Washing machine also is a heavy draw so looking for at least 20A maybe more so could need 32A. The jump between the too means different cable sizes so I would go for 32A feed. This will not be taken from any existing circuit it will need to be a new circuit.

Because it will be a new circuit it will need to be notified and this is the real problem. If not already on your notification to building control then the fees can be silly. Where I live in Wales the first band of charging is for £2000 so it does not matter if the job would cost £20 or £2000 the council charge is the same. Last time I asked it was £100 plus vat. A scheme member electrician however does not pay the council direct but his scheme provided which means he pays a lot less to notify. So often it is cheaper to get the work done for you than to DIY.

There are forms which allow design, installation, and inspection and testing to be done by 3 different people but in the main the scheme providers will not allow their members to use these so to use these forms means local council again. So really defeats the whole idea of DIY.

I would suggest you get a quote and compare prices first. Tradesmen for what ever trade tend to work faster than the DIY guy and as a result often it is just not worth all the hassle of DIY.

Clearly we are not able to design a system on a forum. And your question is really all about design. What I would say is something you need to consider is how you will protect with RCD's. They come in may flavours from basic twin RCD's in a consumer unit. To multi RCBO's and even to types with warnings when the leakage is approaching the point when they are likely to trip (See X-Pole). Also for special circuits like freezers special cable can be used so these items don't have RCD protection so they are less likely to fail due to circuit tripping. I would consider Ali-tube cable for the fridge/freezer supply. Also cooker supply where older type electric cookers are used earth leakage can be a problem. Selecting a cable or route which does not require RCD's to be fitted may be a good move. With induction hobs there is not the same problem. Also lack of water around an oven means they don't have same problem as some of the cheap hobs.

I hope I have been helpful? Don't like quoting rules too much want to give reasons instead. So I would get a quote then consider next step.

 

[maltaron]

BAS, who wrote that wording for someone to sign? I have just built an extension including a new kitchen, I wired it myself under building regs, the council electrician checked first fix, then completion, then gave the certificate to the Building inspector. At no time did I sign anything nor was I asked for design details or testing details. But to be honest, what design is required for 2 standard ring mains and an extension to existing lighting in domestic situations.

 

[ban-all-sheds]

BAS, who wrote that wording for someone to sign?

The IET.

If your method for complying with Part P is to comply with BS 7671, then issuing an EIC is required.

And nobody should be doing work of that magnitude unless they can, and know they are justified to, sign an EIC.

I have just built an extension including a new kitchen, I wired it myself under building regs, the council electrician checked first fix, then completion, then gave the certificate to the Building inspector. At no time did I sign anything nor was I asked for design details or testing details.

I'm not surprised at the latter.

But you were wrong to even start the job if you were not able to certify it.

But to be honest, what design is required for 2 standard ring mains and an extension to existing lighting in domestic situations.

Balancing of the loads around the ring...

Deciding that a ring is an appropriate design in the first place...

Using the correct sized cables given the installation method(s)...


And then there is the testing....

 

[maltaron]

For your info BAS, I had all design details and all the test results fron proper calibrated test gear. I made the point because you made a statement that someone had to sign a declaration, but at no time did the BCO or Council Electrician request this.