Cooker Circuits

[kevm5]

Hi, I am about to install a new kitchen with the following appliances:

http://www.ikea.com/gb/en/catalog/products/50123027
http://www.ikea.com/gb/en/catalog/products/50123008
http://www.ikea.com/gb/en/catalog/products/70109898

I'm unsure of the rating to get the correct size cables/MCBs. The ovens will be mounted in the same unit, but the hob will be on a separate wall.
Also, I'd like to future-proof the new CU I'm installing as in the future, I will run a cable out to the garage to serve a mini CU for a light, socket for the odd power tool/washer and a washing machine and tumble dryer. What size MCB will this require?
I understand all about part p; I'm an army electrician, I'm planning to do the work, test and inspect with equipment from work (so I know it is a safe installation) and I will get part p registered spark to certify as and when I need to.
Thanks.

 

[flameport]

I understand all about part p;

Clearly you don't:

I'm an army electrician, I'm planning to do the work, test and inspect with equipment from work (so I know it is a safe installation) and I will get part p registered spark to certify as and when I need to.

That is not going to happen.

There are only 2 options:
1. You notify LABC before any work starts. They then inspect the work as required to confirm compliance with building regulations.
2. A member of a competent persons scheme does all of the work themselves and notifies building control via their scheme provider.

As for the circuits, the hob would probably require a 32A circuit and the ovens 16A each - but the Ikea site does not have any rating information for the ovens.

 

[kevm5]

Thanks for your swift reply,
OK, so.... I recently bought this house (my first after many years in rented quarters) and it doesn't come with a part p cert. Firstly, it didn't put me off buying it. If I got a sparky to look at it, he would recommend a full rewire (££££££££) which is pretty much what I'm doing now. If I had just bought it, and let's say, it did have a proper CU instead of a rewirable FB, the ring mains did follow round the house in some sort of upstairs/downstairs order and not up/down front/back in no sensible direction and I got a sparky in then, if he wasn't one of the stars of "Rogue Traders", would he still recommend a rewire (£££££££) if the test results were good? You're not trying to tell me that every installation in the land has to be redone so that buried cables are more than 50mm below the wall etc.?
I understand that there are some cowboys out there that would try to DIY and leave a house dangerous but, although I haven't been on the tools for my entire career, I have a young family and I don't want to put them in any harm, which is why once I have finished, it will be fully tested and inspected.
By the way, I've just had the pleasure of the LABC's presence to look at a wall between the kitchen and dining room that is coming down. The builder who has many more years and experience than the BI said it wouldn't need calcs - BI told me to get calcs just in case; thanks, £115 for the visit, £300 for the structural engineer's report. Mega! It is my house and not the council's?

 

[Spark123]

It may be your house, but wether or not you like it the law (which in includes the building regulations) still applies to your house.

There is no requirement for cables to be buried below 50mm, the requirement is that if they are not then they are RCD protected (30mA max). Any spark looking at your installation will be comparing it to todays standard - not last years.

 

[kevm5]

As for my original post, I will run a separate circuit for the hob, but would it be easier to run a single cable from a 32A MCB to feed a mini CU with 2 16A MCBs local to the ovens? The run will be less than 10m. I guess it depends on how many ways I have on the main CU?

 

[Spark123]

Just as easy to run 2 circuits directly from the CU, probably cheaper too.

 

[kevm5]

OK, I get that, so by law, every house now needs to comply to part p, which means I was sold the house in an illegal state?

 

[kevm5]

Just as easy to run 2 circuits directly from the CU, probably cheaper too.

Thanks for the answer!

 

[Spark123]

What is the kW rating of the oven? Seems to be missing from the info list - or am I just missing it!

 

[kevm5]

6mm cable for the hob, 2.5mm for each of the ovens?

 

[kevm5]

What is the kW rating of the oven? Seems to be missing from the info list - or am I just missing it!

"Energy consumption with a standard load, top and bottom heating: 1.10 kWh.
Energy consumption with a standard load, forced air: 0.79 kWh."

 

[Spark123]

kWh is a unit of energy - need to know what current it will take i.e. Watts/Volts = amps

Possible 2 x 2.5mm circuits for the ovens will do, without knowing what current the oven uses I can't say for sure.
Don't forget to have some sort of local isolation for each one also.

 

[kevm5]

kWh is a unit of energy - need to know what current it will take i.e. Watts/Volts = amps

Possible 2 x 2.5mm circuits for the ovens will do, without knowing what current the oven uses I can't say for sure.
Don't forget to have some sort of local isolation for each one also.

Thanks, a double pole cooker switch for each, within 2m of the appliances.
Seeing as the staff at Ikea or Whirlpool can't tell me, is it worth running out a 4mm cable in case it's bigger when it arrives?

 

[flameport]

It is entirely possible that the ovens will run from 13A fused connection units, or plug in to 13A socket outlets, or it may be possible to connect both directly to a single 32A circuit. This can only be confirmed once details are obtained from the manufacturer of the ovens.

Installing a CU in a kitchen just for cooking appliances is ridiculous. If 3 circuits are needed, then install 3 circuits.

As for the rest of the property - if the existing fusebox is being replaced, a full test would be carried out on the existing circuits. If they are acceptable, they can be connected to the new CU. If not, then they will have to be repaired or replaced.

Old doesn't have to mean useless or dangerous, and there is no requirement to rewire everything just because it was installed 20, 30 or even 40 years ago.
Regulations are not retrospective (otherwise every property in the country would have to be rewired every few years). However any new work should comply with the current regulations.

 

[Spark123]

20A DP switches might be easier for the ovens - can you see the kW load in the instruction manual for the oven?