MCB size and wire size for an electric oven and induction hob

[owen42]

Hello

I have two new appliances
Electric oven rated at 3.95 KW
Induction hob rated at 7.2 KW

total of 11.15 KW

Currently it is on its own supply with a 10mm Twin and Earth and the MBC is 32amps

Can you please advise if the following

Cable size is sufficient ( behind plaster )

MCB Amp needed and can I use the new ones now as my cu is old

Thanks in advance

 

[brianmoooore]

Diversity for a domestic oven/hob is usually taken as 10A + 30% of the remainder.
11150W = 48.5A, so 10A + 30% of 38.5A = 21.5A.

 

[owen42]

Diversity for a domestic oven/hob is usually taken as 10A + 30% of the remainder.
11150W = 48.5A, so 10A + 30% of 38.5A = 21.5A.

Thank you, so am I able to run the two appliances on the one circuit?
And what size mcb 45 or 50amp

 

[brianmoooore]

32 is already a bigger number than 21.5, so why do you want to change the MCB?

 

[owen42]

HI,

32 is already a bigger number than 21.5, so why do you want to change the

32 is already a bigger number than 21.5, so why do you want to change the MCB?

Hi because the oven requires 16amp and the hob is 30 amp and I only have the once circuit

 

[brianmoooore]

Hi because the oven requires 16amp and the hob is 30 amp and I only have the once circuit

Which, after diversity is applied, is 21.5A. My personal opinion is that the standard diversity is on the excessive side, but 21.5 to 32 is nearly a 50% margin, which is plenty.

 

[owen42]

Diversity for a domestic oven/hob is usually taken as 10A + 30% of the remainder.
11150W = 48.5A, so 10A + 30% of 38.5A = 21.5A.

Thank you for your reply, so I don't really want to run a separate circuit to split the oven and hob up.

so with this calculation do you think I am ok ?

Would you upgrade the MCB to 40Amp or 50Amp

I have and older contactum

thanks

 

[DPG]

Thank you for your reply, so I don't really want to run a separate circuit to split the oven and hob up.

so with this calculation do you think I am ok ?

Would you upgrade the MCB to 40Amp or 50Amp

I have and older contactum

thanks

The calculation that Brian did for you took into account both appliances.

 

[Midwest]

I tended to treat a job and oven as two separate appliances, when applying diversity’s, but with only my thumbs to count on, still think that’s ok?

 

[brianmoooore]

I tended to treat a job and oven as two separate appliances, when applying diversity

You wouldn't if it was a slot in, or the type where although the hob and oven are separate units, they are connected directly together by a plug in cable.

 

[Midwest]

Sorry meant hob not job! Most I installed were separate, sometimes different manufacturers.

 

[owen42]

The calculation that Brian did for you took into account both appliances.

Thanks

 

[owen42]

Sorry meant hob not job! Most I installed were separate, sometimes different manufacturers.

Lol difficult as I am replacing the oven and hob only as the kitchen is already installed, so installing a new 10mm wire to allows for a second feed would be difficult

 

[brianmoooore]

In plain, simple English: Your existing supply cable and existing MCB are more than adequate for your new oven and hob.

 

[owen42]

In plain, simple English: Your existing supply cable and existing MCB are more than adequate for your new oven and hob.

Thanks, just wanted to double check many thanks

 

[owen42]

Question how can you tell what size the cable is when it's not printed on the cable ?

 

[brianmoooore]

Question how can you tell what size the cable is when it's not printed on the cable ?

Looking at it plus experience, but in the absence of that, measure the diameter of a conductor with callipers or a micrometer, and calculate the cross sectional area.

 

[owen42]

Looking at it plus experience, but in the absence of that, measure the diameter of a conductor with callipers or a micrometer, and calculate the cross sectional area.

Thanks I have attached some photos just to see