Last year I had an oven, induction hob and new consumer unit ( replacing the old ceramic fuse box that was fitted in the 70’s ) fitted.

The induction hob is on its own circuit

I get the circuit breakers tripping when the kettle, microwave and oven are all on together. The oven has a quick heat function which is fantastic, but will generally trip the breaker if the other items are used at the same time. The microwave is 900w and the cooker 3.65Kw.

Should a domestic kitchen circuit be able to take that sort of load ( cooker + kettle + microwave ) or is it a case of specifying a lower rating circuit breaker than should have been ?

Watts = volts x amps

240v x 13a = 3120 watts

So I’d say no.

IANAS

I’m not qualified !

However, I can run the oven, microwave, induction hob, extractor hood and other domestic gadgets without mine tripping.

The MCB’s for the kitchen are on their own consumer unit. The main MCB is 64A the others are 32.

So in true STW fashion, I’d say yes 😀

What size mcb is fitted? Normally it’s a 32A on a ring so it’s unlikely that would trip. The main job of the mcb is protect the cable so if a lower rated mcb has been fitted then there might be a reason but I’m struggling to think of a good one other than to cover up a bodge. 3.65kw is pretty high for a single appliance on a ring. Normally once you go over 3kw you fit a dedicated circuit but maybe it’s ok with diversity (the assumption that everything isn’t on at once). The fact that it is tripping regularly means something is wrong and needs looking at. Ideally I’d fit a dedicated circuit for the oven but that’s a lot of messy work now.

Just totalling the amps for oven/kettle/microwave easily takes you over the likely 32A the breaker will be tripping at, so it’s no surprise it’s happening. Increasing the size of the breaker will bring you closer to the point you’re risking overload of whatever cable has been used.

Your socket ring does not have the capacity for normal usage – you should be able to use a normal range of appliances at the same time – the oven needs its own circuit basically.

I wouldn’t be particularly happy with the spark who thought that arrangement was adequate and signed it off.

What’s the capacity of the hob circuit? It’s possible you may be able to put the oven onto that if it is sufficient.

What size mcb is fitted?

I was going to check this morning on the way out, then totally forgot – D’oh.

I wouldn’t be particularly happy with the spark who thought that arrangement was adequate and signed it off.

I’m coming round to that way of thinking too.

I’ll double check the rating of the breaker and maybe think about putting the oven on its own circuit if that is possible.

A 3.65kW oven shouldn’t be plugged into a normal plug and socket – it needs to be wired directly into an outlet plate. It *should* have a fuse on the outlet (manual usually specifies 16A) but I’m pretty sure there aren’t UK fused outlets over 13A so normally it would be on it’s own 20A MCB from the consumer unit.

The kitchen ring will likely be 32A – 7.7kW

Kettle will be between 2 and 3kw so you’re only likely just at the limit even with all 3 on but you are pushing it.

It does only trip when the rapid heat mode is used on the main oven or if the oven in the microwave is used as well.

My apartment is in Holland, so different regulations apply – I’ve never seen an outlet plate for an oven here.

Ah – I know nothing about Dutch wiring regs or practices. One way or another you’re overloading the MCB, which is there to stop the cable running to the appliances acting as the fuse (ie overheating and melting). You need to either –

Get a new cable run for the Oven
or
not use everything at once.

I’d go with putting the oven on it’s own circuit, a breaker, a bit of wire and a face plate is not much, if the routing is fairly obvious you could do it yourself easy enough, but it’s not a big job really.

I’m not sure, it is an apartment with nice, solid concrete walls. When the induction hob was put in they said that they couldn’t get new wire to the same location the oven is in, though I’m not sure how hard they tried.

Does sound like a compromise/easy option based on that. Unfortunately, not a compromise that works very well for the client!

I’m a kitchen fitter and it sounds like the problem we come up against more and more.

Basically they’ve cheated by putting the (3.65kw) oven on the ring, as by the sounds of it they couldn’t be arsed to get a decent sized cable to where it needed to be. We always put in a dedicated circuit for anything over 13a as usually in the UK most kitchens only have 1 available over 13a.

Induction hobs, Pyrolytic Ovens and Combi Microwave/Oven are all generally over 13a and a lot of kitchens these days have all 3!