Standalone induction cooker (Diversity question)

I am DIYer but feel i have a fairly simple but reasonable grasp of physics (work as medical Doctor)

I Just moved into new house so we bought a new standalone induction cooker (Belling FSE 60I) and was perplexed to find they suggest a 32amp fuse/MCB is all it requires (and to use 6mm2 cable from the terminal outlet to the appliance). Im a little unsure how they calculated the maximum demand for this.

It has two ovens and it has 4 'burners' and these all also have boost options to increase the power supplied to them by up to 66% for rapid heat up/ boiling etc.

It states on the databadge the Electrical load is 10466-12455W

We have a CCU (that has a socket also) so i could understand if they have used diversity rules to calculate ( 10 + (30% of 12455/230) +/- 5 = 10 + 16.25 +5 = 31.25
My surprise however is if it were sunday roast or Christmas and had everything on full whack then surely this would use the full 12455W and so work out 54 Amps that would easily trip a B32 MCB ?

Or am i being dumb and have all my calcs messed up?

P.S. Ive not installed it yet due to not trusting the manual I will prob get a sparky in to do so

what's biology and human anatomy got to do with the finer points of thermodynamics and such?

the boost function turns other "rings" down to half power so the overall doesn't change..
the "rings" are pulsed to maintain the required temp and the ovens will have thermostats and cycle on and off..

The diversity rules give you a "worst case" answer if you don't know any better in the situation for which you want to apply diversity.

The manufacturer will know a bit more than nothing about his appliance.You are safe to use his suggestion.

And I would run 10mm and put it on a 40A

After the diversity calcs it is too close.

I would certainly dispense with/remove the socket.

If the maker says it needs a B32 then that's what it needs.

I would certainly dispense with/remove the socket.

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Thanks so much for all the quick replies!

My Problem with removing or replacing the CCU to remove the socket is that it is a combined socket and CCU. The kitchen tiles are grouted up to the edges. To change this to a standalone CCU would mean having to find and cut new tiles when i take the old unit off.

Is there a way of simply blanking off the socket?
I suppose i could just put in a plug blank over the socket and never use it but not the safest of options probably.

BTW the manufacturer doesnt specifically say a b32 MCB it simply says to use "a double pole unit of 32 ampere minimum capacity with 3mm minimum contact separation at all poles". And elsewhere says hard wired using 6.0mm flexi T&E cable and 32 amp fuse.

I guess the B32 MCB that was previously used for the cooker in the Consumer Unit will be fine for this cooker, but from what i remember they had an old electric spiral ring standalone cooker so presume this would have less load than the new one ive bought

hope it will be ok

I would agree with you that with an induction hob with boost the 32A supply does seem a tad on the light side.

In theory we should follow manufacturers recommendations but one wonders in this case if someone has included a general instruction rather than doing a proper assessment for the particular appliance.

However I have many times looked at a consumer unit with a couple of 45A MCB's for showers followed by 4 x 32A MCB for cooker, garage and two ring mains then a 15A MCB for immersion and 2 x 6 amp for lights and all supplied from 80A incoming fuse. In theory wrong but in practice very rare for the main fuse to rupture.

Although if one was to use two large pans with cold water and switch on the oven plus use grill an overload could happen in practice the oven is normally switched on well before we start to use rings and as a result likely it will be switching on and off well before rings are used.
It is also unlikely we would put two cold pans on the hob at the same time. It is likely the manufacturer has done some testing before putting the unit on the market so I would tend to follow his recommendations and only worry if the MCB trips out. I will point out it states "Fuse size" and says nothing about using a MCB which would make sense with an induction hob as MCB's are too slow with semi-conductor faults to protect and special semi-conductor fuses may be required. However it does not say this on the web site.

There seems to be three sizes of fuse to cover whole range of free-standing cookers. 3A (Gas) 13A and 32A the fact that they do not group all together but state requirement for each model I would assume they have tested them with this size so would not worry.

Worst case is fuse blows.

As to education anyone who thinks one can get a degree in any subject and not understand basic maths I would expect has not got a degree. However I would admit that even with a degree in electrical and electronic engineering very little was taught as to how a house should be wired and it still surprises me to find people will accept my word because I have a degree but question my son who has a C&G 2391 which is far more reverent. Although I also have C&G 2391 and C&G 2382 I am never asked about these once they know I have a degree which is really daft.

But ask most people what is an imaginary number and they think it's connected with accounting "i" or in my case "j" is the last thing they imagine? Only those with either "A" level maths or level 4 and above realise what is rational or real as π said to i!!!!!!!!!

ericmark said:

my son who has a C&G 2391 which is far more reverent.

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Hallelujah!

nabowron said:

I am DIYer but feel i have a fairly simple but reasonable grasp of physics (work as medical Doctor)

I Just moved into new house so we bought a new standalone induction cooker (Belling FSE 60I) and was perplexed to find they suggest a 32amp fuse/MCB is all it requires (and to use 6mm2 cable from the terminal outlet to the appliance). Im a little unsure how they calculated the maximum demand for this.

It has two ovens and it has 4 'burners' and these all also have boost options to increase the power supplied to them by up to 66% for rapid heat up/ boiling etc.

It states on the databadge the Electrical load is 10466-12455W

We have a CCU (that has a socket also) so i could understand if they have used diversity rules to calculate ( 10 + (30% of 12455/230) +/- 5 = 10 + 16.25 +5 = 31.25

Click to expand...

i would say its 10+12.6+5=27.6, not that it makes much difference in this case

My surprise however is if it were sunday roast or Christmas and had everything on full whack then surely this would use the full 12455W and so work out 54 Amps that would easily trip a B32 MCB ?

Click to expand...

It might use full whack for a little while, but as others have said, there is only a small likely hood of this. Also, a MCB has time/current characteristics, they don't necessarily trip the moment the current its passing exceeds the rating. As a rough guesstimate, a B32 would probably take 2.5 hours to trip at 54A. If you cooker exceeded this time on full power, it would suggest getting something which isn't going to cost the earth to use.

Or am i being dumb and have all my calcs messed up?

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not really, a little bit

P.S. Ive not installed it yet due to not trusting the manual I will prob get a sparky in to do so

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not a bad idea at all, probably won't cost too much and will provide piece of mind.