Induction Hob - what is the maximum rated power hob I can install in conjunction with a with a 3.5KW oven on a 32A cooker circuit?

[EFLImpudence]

This seems to suggest a 20A supply is sufficient? Or am I reading that wrong?

Induction hobs can be limited when the supply circuit is small - yours is not.

 

[EFLImpudence]

What can I quote to the developer (and ultimately, the electrician) to persuade him that this is fine?

Tell him to look at the vast majority of cooker circuits in the U.K.


Show him this thread and countless others from people whose "electricians" did not know what they were doing.

 

[JohnW2]

This seems to suggest a 20A supply is sufficient? Or am I reading that wrong?

You are reading it correctly. In fact, it is also seemingly saying that the hob can be configured such that 16A, 13A or even 10A supplies are sufficient (although that obviously does not include the oven).

 

[yo61]

I'm going with this back to the developer:

The IET On-Site Guide BS 7671:2018+A2:2022 contains clear guidelines in the appendices for calculating the current requirements of circuits, taking into account diversity.

From Appendix A, Table A1, the current demand to be assumed for a Household cooking appliance is “The first 10A of the rated current plus 30 % of the remainder of the rated current plus 5A if a socket outlet is incorporated in the control unit”.

Doing the calculation for the Neff T69FUV4L0 Induction hob which is rated for 11.1kW @ 230V:

11.1kW @ 230V = 48.3A
10A + 30% of 38A = 21.5A

In other words, a 32A circuit is more than sufficient to power this appliance.

Further, from Appendix H4 “Cooker circuits in household and similar premises”:

“The rating of the circuit is determined by the assessment of the current demand of the cooking appliance(s), and the cooker control unit socket-outlet if any, in accordance with Table A1 of Appendix A. A 30 A or 32 A circuit is usually appropriate for household or similar cookers of rating up to 15kW."

Can you please ask your electrician to look at this again as I think the above information demonstrates conclusively that he/she is wrong to refuse on safety grounds to install or sign off the installation of this appliance on a circuit rated for 32A.

I'll let you know how it goes.