Confused, swapping 5.8kW ceramic hob to 6000w induction, straight swap or need second cable?

Quay_Koncept

Hi Guys, I have looked through a lot of threads on this yet still slightly confused, just wanted to confirm if this daisy chained setup is ok

Breakerjpeg.JPG

Old ceramic hob:  5.8 kW

Old Double oven: 5.2 kW

New Induction Hob:  6000 W (Current 2x16A or 1 x 32A)

New Single oven: 2990 W

Fuse-box cooker breaker says  “B32” which feeds 1 wire (I assume this means the circuit is 32amp and has the according 32amp capable cable. Is this a straight swap or do I need to get an electrician in to run a second cable?😚 Picture of breaker and kitchen cable included☺️

micks_address

https://www.boards.ie/discussion/2058308578/confused-swapping-5-8kw-ceramic-hob-to-6000w-induction-straight-swap-or-need-second-cable

so in theory you could have both the oven and hob on at the same time.. 32 amp would cover about

7680 Watts - so I'd say you need a separate circuit for both the oven and the hob. You could be using over 8000 watts with the new combination. When we changed our gas hob to induction we had to get a new circuit run back to the consumer board. Wait for someone who's qualified to comment though!

Quay_Koncept

Thanks Mick, grande, i dont want to be buying these and have it tripping out, if it makes any difference to future posters even at peak use (ie xmas day) we would only ever run say two hobs and the oven never ever 4 hobs and the oven simultaneously as small family. On old hob we only ever used 2 of the 4 elements the biggest and smallest 😊

Calahonda52

Is the thread title misleading?

IMO you need to wire for whats possible as opposed to your usage.

Looking at the numbers, you had a max of 11 kW, you are now looking at 9 max

What size is the cable, difficult to tell from the pic.

How far is the cable run from the fuse board to the units?

I have a 9kW elec shower and its a 6 mm sq cable.

Am not a sparks

Quay_Koncept

cable2.JPG

Hi Calahonda yes your are correct, it should be wired for whats possible, so forget I said that lol 😁, So I looked at cable and took a photo it appears to be 13.89mm thick side & 8.69mm thin side. Cable run is approx (Assuming it goes through outter wall and not fed up into attic and back down to fusebox for some reason is 15 meters

cablejpeg.JPG

10-10-20

@Quay_Koncept, consider uploading images rather than a document as many of us won't open random documents off the internet!

Quay_Koncept

Sound 10 just redid the pics and will do from now on:)

Quay_Koncept

Right so, Calahonda picked up on the Double oven being switched to a single, so the power consumption has indeed dropped. I was confused as to the difference between the low kW power consumption figures on the old applicances and the high W figures on the new applicances. With the help of Chat gpt I discovered 6000 W is in fact 6kW and so on. Based on this I have converted all the numbers to kW.

 

Old Double oven and ceramic hob:

Old ceramic hob: 5.8 kW

Old Double oven: 5.2 kW

Total power consumption: 11kW

 

New single oven and induction hob:

New Induction Hob: 6 kW

New Single oven: 2.9 kW

Total Power Consumption: 8.9kW

So there’s no need to run a second cable, Thanks all for input J. So for any future readers wanting to upgrade to induction but without the hassle of getting a new cable put in, switching from a double oven to single may make sense depending on figures.😀

micks_address

would the 8.9kw be over the load of your 32 amp breaker?

dazed+confused

Yes.... but....

Only on Christmas Day will you have the oven and every ring on at the same time.

Do you really want it tripping out that day though?

If it was my house I'd be running a second cable.

dazed+confused

8,900W÷230V=38.7A

2011

A few points:

1) The rings on the hob are all controlled by thermostats as is the oven. This means that once up to temperature each of these loads will cycle on and off. Therefore even with everything turned on to the max setting the average load will fall well short of 8.9 kW.

2) MCB’s will not instantly trip when their rated current is exceeded by 10, 20 or even 50%. Have a look at the curve for a 32A B type MCB. B type are typically used in domestic installations. See link:

https://www.se.com/au/en/faqs/FA290880/#:~:text=B%20Curve%20means%20the%20MCB,10%20times%20full%20load%20current.

Lenar3556

https://www.boards.ie/discussion/comment/120959050#Comment_120959050

There is the concept of diversity, whereby you usually don’t account for everything drawing full load at the same time.

Otherwise you would end up with massively oversized installations if you were providing for everything drawing full load at the one time.

To put it in perspective, it is not uncommon for six houses to be fed from a 15kVA transformer by ESB.

The bigger issue might be whether your new oven will have sufficient overcurrent protection if you simply wire it along with the hob of a 32A MCB. A lot of them are designed to be connected via a fused connection unit at 13A.

Quay_Koncept

https://www.boards.ie/discussion/comment/120959151#Comment_120959151

I dont see how it could as I have been using appliances rated up to 11kW for last 15 years, my power consumption on this new setup in theory is lower by 2.3kW by switching from a double oven to single.

Quay_Koncept

https://www.boards.ie/discussion/comment/120959195#Comment_120959195

Most we would have on is the oven and say max 2 rings if even(even thats rare i cant even recall ever seeing that here), normally meal time is either oven baked or pot baked rarely a mixture of two. Use air fryer a lot too and microwave. We are not the best cooks here. Everything is quite basic 😊

Quay_Koncept

https://www.boards.ie/discussion/comment/120962568#Comment_120962568

Spot on Lenar re 13A fused connection unit, just noticed in manual it mentions a "miniature circuit breaker". Exisiting setup has an isolation switch only. Ill get an electrician to fit one alongside the isolation switch so.

astrofool

https://www.boards.ie/discussion/comment/120963501#Comment_120963501

This, I think you're overcomplicating this, if you're worried, ask an electrician to install, they'll likely continue to use the existing setup which has a higher potential load.

kirk.

Follow manufacturers instructions but I don't think the loading would be a problem

Did I read something about induction hobs having less diversity applied maybe because of a boost mode ? ,might not be correct

Risteard81

https://www.boards.ie/discussion/comment/120955266#Comment_120955266

Diversity means that in reality you won't draw that load. In reality the existing setup should be absolutely fine (even on Christmas Day).

Quay_Koncept

Hi there, just for anyone that has the same query in future that comes across this thread. It worked absolutly fine, just connected up using same wiring as the old ceramic hob. And my god the differenece between the older ceramic hob and induction is unreal. Upgrading to induction well worth it. Before If I was say boiling water to make pasta or rice, if you put a pot of water on the ceramic hob it would take 12 - 15 minutes plus to come to the boil, so I would boil water in the electric kettle then add to the pot. With induction you can put a full pot of cold water straight from the tap and its approx 50% faster then ceramic hob if not more. I reckon this cuts down on your leccy bills over time too. Thanks for all the replies from the guys on here to give me the confidence to take the plunge. Thanks again :)

Risteard81

https://www.boards.ie/discussion/comment/121145687#Comment_121145687

I find that my induction hob boils water (on power boost mode) faster than the kettle. As you say, it's cheaper in the long term with induction as the energy is only used to heat the pan and is not wasted - also incredibly responsive.