New kitchen, cookers different place.

[KeithE]

Hi, Before I start any changes that I make will be thoroughly checked over by a professional electrician for official sign-off. I am doing it as I am a capable DIYer and want to save costs while enjoying the fruits of my labour.
Having said that I am installing a new kitchen where the existing 900mm Range cooker is being replaced by a 600mm Induction hob at the same site, but an integrated oven and combination oven in a tall unit the other side of the kitchen. I have included images of the current wiring. The top isolator is just for the extractor fan and will stay for the new fan. The bottom isolator is for the oven and very thick cabling as shown (white). I am thinking of running 10mm cable from the junction box or the isolator switch (this would be easier) through the wall then behind the coving, down the outside of the wall behind where the kitchen units are going and putting another double pole isolator switch there ready for the two ovens. The wall units are very tall so external cable run and isolator switch would be difficult to see. I know not to put the new isolator switch above the cookers. The isolator switch will be accessible above the fridge freezer. The 10mm cable will b e roughly 6m run around the walls between the isolator switches.
Does this all sound theoretically feasible, electrically?
Many thanks for any helpful post responses - this is a great site.

 

[littlespark]

If your’e getting an electrician to sign it off, can’t you get them in first to design the circuit?

A combi oven does not need 10mm supply. Check the wattage of the equipment.

If I understand your description…. You have an existing cooker circuit, you want to split this and take one leg to the new hob, and the other leg to another location in the kitchen to supply the oven via a second isolator?

It’s possible. But you need to find the total wattage of both appliances, apply diversity, and then find out cable sizes, which in turn defines OCPD size.
May not be same as your existing equipment.

There’s also RCD protection to consider, and running your new cables in safe zones.

 

[KeithE]

If your’e getting an electrician to sign it off, can’t you get them in first to design the circuit?

A combi oven does not need 10mm supply. Check the wattage of the equipment.

If I understand your description…. You have an existing cooker circuit, you want to split this and take one leg to the new hob, and the other leg to another location in the kitchen to supply the oven via a second isolator?

It’s possible. But you need to find the total wattage of both appliances, apply diversity, and then find out cable sizes, which in turn defines OCPD size.
May not be same as your existing equipment.

There’s also RCD protection to consider, and running your new cables in safe zones.

Thanks littlespark. It is possible that either the oven or combi oven requires just a 13 amp plug, the sales assistant wasn't entirely sure, but I thin I remember seeing in the specs one was only 13amp requirement. There is one to hand anyway. Re the cable, running the 10mm cable, which is already in the surface mounted junction box, is not a problem and I understand more than sufficient for both ovens. Having 10mm rather than 6mm running to a double isolator switch surely isn't a problem? My current range cooker is a double oven so cannot see a problem with ampage but I do take your point re OCPD. Behind walls and behind Coving would surely be considered 'safe zone'.
Lastly why RCD protection if I am simply re appropriating the existing wiring for a slightly different application. The house is only 20 years old.
Thanks again
Keith

 

[littlespark]

You probably have rcd protection on the circuit if the existing cooker switch has a socket on it.
If not, you will need one. (20 year old should have one already)
Any new circuit, or alteration to a circuit must be brought up to most recent regulations. Therefore rcd protection.
It’s easier to just add the rcd than work out whether a particular circuit actually needs it or not. It’s down to use of the circuit, the type of wiring and the route it takes through the house..

Many ovens do indeed come with a 13A plug, but to just plug it into a general socket in the kitchen, along with toaster, kettle, dishwasher etc etc can be too much.

If at all possible, I’d run a 32A dedicated radial circuit in 4mm for the oven direct from CU… future proofing for possibly a bigger appliance later on.

 

[westward10]

You may well be a dab hand at a bit of DIY but this electrical work is clearly beyond your level of competence so use an electrician from the off. Safe electrical work is not about saving costs.