Cooker/Hob Circuit

[AndyNewBuild]

Hi all,

I know the following is all notifiable and it has been!

I'm installing a new kitchen and trying to organise the electrics for the cooker, hob and other appliances.

I was going to put the cooker and hob on their own circuit protected by a 32A MCB using 10mm T& E. How would you suggest connecting the hob and cooker on the same circuit? Working with 10mm is rather difficult and would appreciate advice on the easiest way to wire both the cooker and hob.

I was going to use a grid switch for the washing machine, dish washer, extractor and water heater (on separate circuit). Can I simply loop in and out of each grid switch as a radial circuit using 2.5mm T& E? As the water heater is on it's own circuit, there will effectively be two circuits within the grid switch. I believe this is acceptable provided there is a warning sticker?

Any advice appreciated.

 

[Taylortwocities]

I know the following is all notifiable and it has been!.

Good!

I'm installing a new kitchen and trying to organise the electrics for the cooker, hob and other appliances.

I was going to put the cooker and hob on their own circuit protected by a 32A MCB using 10mm T& E. How would you suggest connecting the hob and cooker on the same circuit? Working with 10mm is rather difficult and would appreciate advice on the easiest way to wire both the cooker and hob..

Can we take a step back first. Do you really mean cooker or do you mean oven? What is the loading of the cooker/oven and the hob.
Why only a 32A breaker for 10mm cable? Are there factors that will derate the current carrying capacity of the cable?

I was going to use a grid switch for the washing machine, dish washer, extractor and water heater (on separate circuit). Can I simply loop in and out of each grid switch as a radial circuit using 2.5mm T& E? As the water heater is on it's own circuit, there will effectively be two circuits within the grid switch. I believe this is acceptable provided there is a warning sticker?
.

Again, think about the max load. The largest breaker you could put on a radial run in 2.5mm would be 20amps. Is this 20A big enough for all of those loads?? Maybe a 32A breaker and run 4mm radial would be better?
MK 20A grids will terminate 2x4mm cables.

The water heater must be on its own breaker if the vessel is more than 15litres. Yes you must post a waring label if there's multiple feeds. MK supply one with their grid kit.

 

[AndyNewBuild]

It's an oven not a cooker, sorry. According to the spec it's 3KW.

I was putting it on a 32A breaker as that was advised by my electrician. He also said that 10mm wasn't required but as I had plenty left over from the shower install, I may as well use it in case the oven was upgraded later. No harm in using larger cable than actually required.

If I use a 4mm radial, will this cable easily connect into the kitchen sockets as well? I could run a 2.5mm ring for the sockets and appliances instead.

The water heater is on it's own circuit but it's 15L anyway.

 

[ericmark]

Regulations like 433.2.1 and 510.2 limit the way a kitchen electrical system can be designed coupled with the sizes of cables that will fit in grid switches and size of current limiting devices over 13 amp it needs careful consideration as to if separate supplies, mini consumer units, ring mains etc are best way to provide the requirements in a kitchen.
Normally the access to the main consumer unit and general layout of kitchen will influence as to which method is used.
To comment on the design without knowing all the facts would not be very helpful and someone who is considered as skilled will have to sign the installation certificate and really you should ask that person your questions.
Having cooker and hob on their own individual circuits makes a lot of sense since then the RCBO or MCB can be changed to fall in with 510.2. Also most 45 amp isolators will take a single 10mm cable without a problem but trying to put two cables in these units can cause problems.
The same goes for the 20 amp grid switches I see no point in making a ring main rather than have each switch with it’s own supply.
514.15 warning notice for duel supply is nothing to do with two feeds from same consumer unit to two switches in same panel. To Isolate the supply you must switch off at a duel pole switch where duel RCD’s are used I would feed all supplies to a switch box from same RCD but having multi single pole overload/fault detection devices feeding a single switch box is not problem.
What the rules are referring to is using a generator and mains supply not to MCB’s.
Eric

 

[AndyNewBuild]

Thanks for the replies.

 

[kablamar]

It's an oven not a cooker, sorry. According to the spec it's 3KW.

What does the spec say about connecting a supply to the oven?