Power consumption of double oven

[mrskiles]

I am just about to install a new supply to a double oven in the kitchen and I have purchased a Hoover HDO889. On the Hoover website it states that the power consumption is 2.8Kw and in the instruction book that came with the oven is states that a 1.5mm2 cable can be used with a standard plug and socket arrangement but on the side of the oven there is a label that says that "P.Maxi = 5110w", which surely implies that the max power is 5.1Kw and thus it draws just over 21Amps? So I am really confused on what breakers and cable I should install, any ideas?

 

[mikhailfaradayski]

sounds like you should call an Electrician to have a look/enquire.

As the cooker is going in the kitchen, this is notifiable work, so you might aswell let the sparky sort it all out for you. No need for you to worry

 

[Chri5]

Just looked at the Hoover site

Max. absorbed power 2.8 kW

WTF is "absorbed power"

You should go with the hand book 5110 w which is about 23a add 13 a for a cooker plate switch with a 13a socket, so the cable needs to cope with a 36a load.

Fuse at 40a MCB and the cable then needs to be able to take 40a load.

Cable size depends on distance between CU and cooker, installation method, grouping etc.

Could you confirm the distance in metres and the method of run (100% under floor, part in plaster, over insulation, in insulation, surface clipped) etc

 

[Diyisfun]

A double oven needs more than a 13amp socket, otherwise there is no point in having 2 ovens.

 

[mikhailfaradayski]

You should go with the hand book 5110 w which is about 23a add 13 a for a cooker plate switch with a 13a socket, so the cable needs to cope with a 36a load.

Hi Chri5, you might want to look at that again

 

[Chri5]

And I thought my mental math was ok

5.1kw divided by 230v is 22.1 amp
5.1kw divided by 240v is 21.5 amp

add the 13 amp single socket = 35.1 or 34.5 amp, so nearest MCB is 40 amp and thus the cable must be rated for 40 amp with the necessary accounting for installation method and distance.

If I'm having a blond moment please explain ,,,,,,,,

 

[mikhailfaradayski]

I was thinking about diversity. Not wishing to be rude, i just cant be bothered to type what is already written, so you might want to look at OSG pg97 and how you would calculate demand on a cooker circuit.

 

[ColJack]

diversity is used to calculate the demand of the entire installation, not individual circuits.. they should be designed to take the maxumum demand..
using diversity I can get a 9.9KW cooker on a 1.5 cable and a 20A breaker... but I wouldn't do it..

9900/230 = 43.04A
-10A = 33.04A
x 0.3 = 9.91A
+10 = 19.91A....

 

[mikhailfaradayski]

Hi Col,

Thanks, i understand that, but the 'add 13A for a 13A socket' bit really needs to be reviewed by Chri5.

 

[Chri5]

Hi Col,

Thanks, i understand that, but the 'add 13A for a 13A socket' bit really needs to be reviewed by Chri5.

I know where your coming from now (a eureka moment), however I'll continue to spec over sized cables for cooker points, reason ?

Well I will always work to the highest demand scenario, a kettle such as this

runs at 3.1kw

So in my view a dedicated cooker point with 13A socket needs to be able to take the full load of both the cooker and the socket in the cooker point.

Quoting OSG at 10 amps +30% of full load + 5 amps for the socket is antiquated and since I'm installing I protect my back with over design.

MCB's be they 6a or 45a cost the same, the cable install time is the same and on a nominal 7m run the cost difference between 10mm and 6mm cable is nominal.

Seriously, a double oven setup can and will use full load- a socket rated at 13a can use full load and yet you use the OSG diversity tables rather than common sense.

Do you get many call backs due to the cooker MCB tripping every Sunday when the client dares to cook meat in 1 x oven, roast spuds and Yorkshire puds in the other and (holly hell) then boils a high power kettle for the steamed veg

Lets beg to differ, but I would appreciate other peoples thoughts !

Is 10a +30% FL OSG table diversity suitable for a modern high power double oven ?

 

[ColJack]

why? it's a 13A socket so you add 13A to the circuit calc..
you only add 5A to the discrimination calc as it's not allways on..

 

[LiamPope]

The official spec sheet says 2.8kW, and the official instruction manual says wire it with 1.5mm flex to a 13A plug. Wouldn't you tend to trust that information? What's this mystery label anyway (photo?)? I think the OP would best be advised to get on the phone to Hoover rather than an electrician (who would probably just get on the phone to Hoover ). Design the circuit when you know what you're designing it for.

Liam

 

[mikhailfaradayski]

Hi Col,

Thanks, i understand that, but the 'add 13A for a 13A socket' bit really needs to be reviewed by Chri5.

I know where your coming from now (a eureka moment), however I'll continue to spec over sized cables for cooker points, reason ?

Well I will always work to the highest demand scenario, a kettle such as this

runs at 3.1kw

So in my view a dedicated cooker point with 13A socket needs to be able to take the full load of both the cooker and the socket in the cooker point.

Quoting OSG at 10 amps +30% of full load + 5 amps for the socket is antiquated and since I'm installing I protect my back with over design.

I wouldn't say it was antiquated, it is in the latest OSG.

MCB's be they 6a or 45a cost the same, the cable install time is the same and on a nominal 7m run the cost difference between 10mm and 6mm cable is nominal.

Seriously, a double oven setup can and will use full load- a socket rated at 13a can use full load and yet you use the OSG diversity tables rather than common sense.

I love common sense. A cooker will use full load, for a short period of time, if you turn both ovens on at the same time. But after a short while, the cookers thermostats will start to cycle the loading.[/quote]

Do you get many call backs due to the cooker MCB tripping every Sunday when the client dares to cook meat in 1 x oven, roast spuds and Yorkshire puds in the other and (holly hell) then boils a high power kettle for the steamed veg .

nope, not 1, , i have an understanding of mcb's time/current characteristics and install accordingly.

Lets beg to differ, but I would appreciate other peoples thoughts !

I never said you were wrong, but considered your advice, perhaps, to be a little bit out and thought a brief review may be in order. After all, you dont allow 13A for every socket on a ring or radial circuit.

Is 10a +30% FL OSG table diversity suitable for a modern high power double oven ?

Probably

 

[ban-all-sheds]

it's not allways on..

Unless Mrs Sheds is in charge, as she seems to think that you need to put 1l of water into a kettle for 1 mug of tea...

 

[ColJack]

even the OSG it says that diversity is for calulating the load for the entire installation, not individual circuits..

it also says "10A plus 30% of the remainder" not "10A plus 30% of the FL"..


as for the missus.. she's following the MI and filling it to the min line...
get her one of these