Electrical Question

16a oven onto a dedicated 32a circuit? new mcb needed?

Hello master sparkies of MyBuilder,

My built-in (mounted under the sideboard, under a separate gas hob), electric single oven has broken. And I'm looking to buy a new one.

To outline the setup:
- Behind where the old oven was, in the wall, is a socket into which the oven can be wired. Note: not plugged - three wires need screwing into the wall and then covered under a plastic cover (also screwed in).
- Above the sideboard is a switch (with a red light on it) marked "OVEN" - it's not like a light switch, it's one of those more beefy switches that clicks up/down.
- In my fusebox, I have a separate MCB marked "Oven" which says "B32" on it - which from what I can tell; this is a 32A fuse?

And here comes the question - in buying a new oven (for random example: http://www.myappliances.co.uk/prod/pyrolytic-ovens/1-ART28742-60cm-single-pyrolitic-oven.htm ) I can see that many of them are 16A. Am I safe to wire in a 16A oven to a circuit which has a 32A fuse on it? Also if not, does this mean that the previous oven (standard cheap one that comes with a new build) was wired unsafely? And more importantly if not, what do I do to get a 16A one installed?... replace the B32 MCB with a B16? Install a separate fuse between the oven and the wall?


3 Answers

Best Answer


Deacon Electrical have hit the nail on the head, the set up is absolutely fine providing that the correct MCB/RCBO is of the correct rating in terms of amp rating. For example the calculation is simple ohms law you take the overall rating of the appliance to be installed for example 7.2kw which equates to 7200 watts and divide this by 230V which will give you 31.30 amps in this instance from this calculation we have proved that a 32A protective device would be sufficient protection for that particular over and that a 6mm cable is ok. However, If the oven you are installing is a 16A oven rating it will require a 16A protective device. It doesn’t matter that the cable be oversized, its only an issue if its under sized for example: This can occur when people change from a single oven to a double oven and then quite often a larger cable size (10mm) and protective device is required in order to be compliant.

By the sounds of it, you just need to ensure that you are certain on the overall rating of the new appliance and secondly that you have the correct rating of MCB installed for it.

If you are unsure I’d advise you contact a local reputable electrical contractor, it should be a very easy job to complete that will not cost you a lot of money.

I hope this helps, Best wishes!

JEM Electrical

Answered 4th Nov 2017

JEM Electrical

Member since 10 Apr 2013

You need to ensure you have a cooker point fitted and wire the oven cable into this.

Plugs can melt at 16 amp!

And change the mcb to a 16/20 amp depending.

Make sure you keep the oven isolation switch.

10mm cable or 6pm is fine but best to check with an electrician and have it properly checked.

Needs to be rcd protected as well!

Answered 4th Nov 2017

Cedar Electrical & Building Services

Member since 31 Oct 2017

The MCB protects the cable not the appliance. Therefore nothing wrong with current set up. If you wire the new cooker to give you further advice would have to know the kw rating of it. Is it a built in, free standing....what?

Answered 5th Oct 2017


Member since 13 Jan 2015

Need help with your project?

We have tradesmen ready to help you. Post a job, read reviews and hire today.

Post a job

Need some help?

Post a job on MyBuilder to find quality, local Electricians who can help you with your project.

Search all questions