I'm refitting my kitchen and the old built in oven was simply plugged in to a socket behind the unit. I had wondered why there wasn't a cooker switch in my flat.
I want to fit another plug in unit to avoid the cost and hassle of having new wiring fitted. I've seen a 16a rated oven in a store which had a plug fitted. It was a 'factory return' so I expect the previous purchaser fitted the plug.
There are some 13a units available but most are 16a or more. I've looked on makers websites and information is often quite vague.
My question is, if the oven is under 3kw, will it be safe to plug it in, normal 13a plug and mains, even if the specs state 16a? Or, must I absolutely stick to a 13a unit (even though some of those state they must be hard wired).
Yes you need to keep to 13A or 3kW versions. A fuse always produce heat and so a plug is always placed in free air to keep it cool. With some cookers there are fans to keep the carcase cool these may also cool a plug with in the carcase and may as a result allow the use of a larger that 3kW oven for some time. But in the end it is likely the plug will fail so not worth the chance.
The regulations say that for fixed appliances you should have a dedicated supply. If you have a dedicated supply then likely it is from a 16A MCB rather than a 32A MCB used with a ring final. If that is the case the 13A socket could be swapped for a 15A socket and since the 15A plug has no fuse no problem with over heating. This was common with immersion heaters at one time to make it easy for plumbers.
So job one is find the fuse/MCB/RCBO feeding the socket used by the oven and see what size it is. If 16A then likely the socket can be changed if on the other hand some one has in error plugged the oven into the ring final then you are limited to 13A in fact you should be looking at having a dedicated supply as in theroy it could over load the ring. In practice it's rarely a problem.
UPDATE - this may help others with a similar question….
I ordered the oven after downloading an online manual from the Zanussi website which stated the oven can be fitted with a 13a plug and run off a normal circuit.
The oven was delivered this morning and I looked at the paper manual that came with it to check fitting instructions and was surprised as it refers only to hard wiring with 15a!
Not wanting to return another oven, I phoned their service dept. and they confirmed that it will be fine to run it off a 13a plug socket (as it says in their online version of the manual!).
It appears that most manufacturers are now only specifying hard wiring fitting instructions even for products that will run off the mains. I suppose in the majority of cases people will have dedicated cooker points and it's best to use those where possible of course.
If one looks at the curves for a 10A fuse will take 20 amp for 200 seconds so around 3.5 minutes and if you set the oven temperature before 3.5 minutes have elapsed the thermostat will have started to switch the oven off.
With a 13 amp clearly longer [img]http://1.bp.blogspot.com/-mL8Frj-Zsdw/Uu9kMCuY33I/AAAAAAAACzo/Qmvu6ar1q-8/s1600/13+amp+fuse.jpg[/img] looking at that curve it will never blow at 20 amp never mind 15 amp.
But one the fuse will get hot and this will over heat a normal plug. With a FCU likely it will not be a problem there is more area to get rid of the heat.
But over time the fuse will degrade. In the end it will blow. It could very well take 10 years before it goes but likely it will fail just when your hosting the dinner party to hopefully gain a new contract. My dad would tape a spare 13A fuse to the FCU ready. He was the overload king.
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