Electric oven on a 16 amp socket

[JohnRoss]

As part of a package for a new kitchen an oven (NEFF B14M62SO) is being installed and the supplier has specified a standard 16 amp socket. I note the total power rating of the oven is 3.45 kW and I feel a bit concerned about drawing 15A from a 16A socket for long periods.

The socket I am putting in is new with screw terminals not a push/click type but it seems a bit marginal for a safety factor. Bit of a disaster if the thing overheated as polystyrene insulation in that wall space. The oven has a moulded on plug I am told so clearly the manufacturer seems happy with a 16A socket. I could easily chop off the plug and fit a 20A one but that may affect the manufacturers guarantee. The previous oven was plugged into an individual 20 amp circuit which I would be extending to the 16A socket and I could change the 20A fuse to a 16A one in the switch on the consumer unit. Any thoughts?..................................JR

[Théière]

 Wouldn't worry, Neff are a well known company and would need to prove relevent safety. Also although the socket is rated at 16 amp that is a continous rating and there is always a safety factor of a least 100%

Our White westinghouse range plugs into a 13 amp socket in the UK and that has two ovens!

EDIT:

It is on a dedicated circuit

[Gluestick]

Personally, knowing the vagueries of rural electricity supplies in France, I would supply the oven from a dedicated and over-engineered circuit.

All depends where you live, I guess, however one of the core problems of EDF rural supplies is supply voltage drifting well below the specified 230 Volt norme, during times of heavy load.

As I did for our Neff Double Oven in UK: which is connected to a 30 Amp Cooker Point and single supply circuit.

[JohnRoss]

Extra information. The oven circuit in question has a switch with a handle that can be pulled out in the off position to reveal a ceramic bodied cartridge fuse and bears the legend Multi 9 SFT 20A 380V. Most of the circuits on the board have switches of this type marked SFT. There are a few circuits with switches with no fuse marked Multi 9 DPN plus either C16 or C10 or C20 or U15A or Déclic C10................................JR

[La Guerriere]

It's old-fashioned but is still OK. I would leave it as it is, because the French cartridge fuses have different physical sizes for different ratings.

[Jonzjob]

When I changed our oven a couple of years back it was just a case of sliding the old one out, unplugging it, plug the new one in and sliding the new one into place. No problems and very straight forward. It's a Siemans oven bought locally.

We too are on a fused consumer box.

[JohnRoss]

Ok but there is nothing to slide it into as I have ripped out the whole kitchen and await the supply of new units, work top, sink etc from Schmidt Niort inc oven and gas hob. Schmidt did drawings of what was required in terms of waste pipe, H&C water supply and electric points. They deliver in a couple of weeks and they fit the week after. I undertook to do the preparation work and the decoration afterwards, silly me!

Did try an interesting experiment today. Wired up this 16A oven socket and plugged in, using a multi-socket extension board, two 2kW heaters. According to the EDF watt-meter the load was in fact 3.78 kW and the incoming main voltage was pulled down by about 8 volts, at the end of a long overhead line! After an hour I pulled out the extension board and felt the plug pins, only slightly warm. Repeated the experiment using a two way adaptor and the pins were almost too hot to touch so I hope the plug on the oven is a good tight fit and the pins not made of some inferior metal. I will repeat the experiment tomorrow just to make sure as it were.............................JR

PS The following info was given on another site and I would be grateful for confirmation of this. As a matter of course any cooker would normally be connected via a 32amp disjoncture and 6mm cable as stated in French norms.

The same source indicated that in France cookers don't usually come with moulded on 16A plugs and should be connected using a domino and cable sortie.

If this is the case then could someone direct me to a source for this info as I could print it out and take it with me as I am visiting the designer of the new kitchen at Schmidt on Tuesday to discuss some other things and it would be helpful to stick it under her nose and see what reaction I get! Last time I was there I asked about the oven supply and she assured me that the NEFF cooker came with a moulded on 16A plug.

[Gluestick]

John:

Remember, that as the effective voltage decreases, then the current (Load) rises.

And it's not just your load that counts: it's also the farmer along the road who suddenly switches in some heavy lump of kit!

Watts Divided By Volts = current (In Amperes).

Which is why, in my book it's best to play safe.

I would never connect a cooker via a plug into a socket: since the contact resistance between the plug pins and the sockets can cause endless probs.

 

[pachapapa]

The french national norm NF C 10-100 requires for a kitchen installation:

Separate Oven 16 Amp socket; Cooker including Oven or a Hot Plate 32 Amp monophase/20 Amp triphase.

http://www.installations-electriques.net/Instal/NIBT/FR_cuisine.htm

[pachapapa]

The manufacturer's "fiche technique" confirms the requirement for a 16 Amp supply.

http://www.neff-electromenager.com/nos-produits/la-cuisson/fours/B14M62S0FR.html?source=browse

A well designed oven will quickly rise to the designated temperature and will then switch on and off depending on the control regime of the temperature transducer; the idea that the oven will stay on permanently drawing  3,450 Watts is fallacious; well I suppose you could sit infront of it on a cold winter morning with the door open warming your feet.[:)]

[JohnRoss]

Much obliged a very interesting table. The section you seem to be referring to seems to be:

four ou lave-vaisselle + lave-linge ou sèche-linge

1 prise 16 A

1 circuit spécialisé par application :   disjoncteur 20 A ou fusible 16 A (fils 2,5 mm2 )

 

In which case Schmidt would seem to be correct in specifying a 16A socket and the manufacturers data confirms that the plug is already fitted, brilliant and thanks again...................JR

[Gluestick]

[quote user="pachapapa"]

A well designed oven will quickly rise to the designated temperature and will then switch on and off depending on the control regime of the temperature transducer; the idea that the oven will stay on permanently drawing  3,450 Watts is fallacious; well I suppose you could sit infront of it on a cold winter morning with the door open warming your feet.[:)]

[/quote]

I question use of the word "Quickly" herein, pach........

Our Neff double oven takes considerable time to reach the desired temperature from cold: obviously, due to the thermal mass of the material.

And if both ovens are being used (i.e. conventional and fan), the constant load is significant. (We both do much cooking!).

And once food is placed in the pre-heated oven space it then must overcome the thermal mass of the food: which is why the temp drops and the element kicks in right quickly.

Bearing in mind that the design voltage of mains in rural areas (i.e. 230 Volts) varies from this mean downwards according to area load then the following immutable realisations of Ohm's Law apply:

Load Constant @ 3,450 Watts.

Voltage 230 (mean): current:  = 15 Amperes:

Voltage 220                 " "         15.68

Voltage 210                " "          16.42

Voltage 205                " "          16.82

Then one must consider the distance from the Tableau to the oven: more voltage drop potential.

And finally, the contact point resistance between the plug and the socket receivers.

Last time I checked, it was quite permissible I believe to over-specify supply wire.

And all this discounts the typical surge current when such a load is first enabled.

 

 

[JohnRoss]

Even allowing for a slight positive temperature coefficient of resistance of the heating elements I doubt that the current drawn is going to increase if the supply voltage falls. I would submit that the 3.45kW quoted is only at a supply voltage of 230 and would be less with a droop in this voltage due to line resistance and the loading effect by other users. The point about droop due to the resistance of the cable between the socket and the consumer unit is a good one and during the experiment I described I detected a difference of between 1 and 2 volts, digital meter resolution limited to 1V on that range, between the socket and the consumer unit/tableau. A dissipation of between 15 and 30W along the length of the cable, makes you think!......................JR

[Gluestick]

I cheated a bit, John!

No: in practice what will happen is this:

"For thermostatically controlled electric resistance heating, hot water heating, electric clothes dryer or process furnace, reducing the voltage results in reduced demand (kW) for the individual unit itself.  The demand (kW) of the individual device is reduced based on I²R, but because the device is thermostatically controlled, the device "on" time will increase as a function of the voltage reduction to maintain the temperature set by the thermostat."

Thus the "On" time would increase, subjecting the supply cable to more constant loading.

Basically, I have this thing about hot cables...........[:)]

[Jonzjob]

Ohms law states that if you have a steady resistance and you drop the voltage then the current will drop too. Therefore the wattage will not be the same but will drop.

The only way to keep the wattage steady with dropped voltage is to decrease the resistance..

Therefore a drop in the supply voltage will lead to a drop in the current. Just try to run a 230 volt bulb on 110v and check the current. Oh yes, and there won't be very much light either [Www]

[pachapapa]

My Moulinex TEMPOS take 136 seconds.[:D]

[Chancer]

I recently brought back from the UK a halogen worktop oven thingy with a big clear Pyrex bowl that I mistakenly thought was a Chinese copy of a Remoska, it isnt because it has a halogen heating element and fan , a much larger capacity and consumes more current than the Remoska when heating.

It does however get up to temperature really quickly, maybe even better than PP4s moulinex and thereafter the on cycles are very short compared to the off cycles and it cooks, roasts and grills food really well.

To date it has totaly replaced my main oven and other than being a bit concerned about the long term reliability of it I will in time take out my main oven and replace with casserolier draws.

[Théière]

He he I bought one of those too but took it back as I didn't think the cooking times in the book were as short as the advert stated, So you rate it Chancer?

[Gluestick]

Mrs Gluey and I are absolutely delighted with our (Rather expensive!) Neff double oven.

As I write, I have stuffed toms and red peppers finishing: together with potato wedges.

In the small oven.

Does take time to come up to temp though, as it's conventional: but for certain dishes much better than a fan oven IMHO.

On a side issue, before doing the cuissine, in la belle: which will be the large major refurb job and a full rip out!), I need next trip to replace our exisiting free standing bottled gas jobby.

Where's the best place to source one in France? I only want a cheap one, 'cos I'll sell it soon after.

Any ideas peeps, please?

[8-)]

[Chancer]

[quote user="Théière"]He he I bought one of those too but took it back as I didn't think the cooking times in the book were as short as the advert stated, So you rate it Chancer?[/quote]

Yes I do [:D]

I have done a roast in it in very little time and it was the best result that I have ever had, cooking for one I dont like to use the big oven and have a mini-four in the UK but here in France the big oven came with the cuisine equipée.

Where I find it particularly effective is grilling or baking foods which would normally splash fat and create smoke and stain a conventinal oven, my mini-four is quite susceptible to this, with this halogen jobby (JML seem to be the biggest seller of them) you can put some merguez on the top rack and within one minute from cold they start to sweat oil/fat which simply drops to the bottom of the dish, they cook and brown very quickly and there is no smoke and hardly any smell either, its quite captivating to watch this going on through the clear cooking dish and of course you dont have to open the door losing heat like a conventional or mini oven to see how the cooking is going.

My neighbour in the UK reckons that for him that is the greatest advantage as he is forever checking on progress, of course with soufflées, Yorkshire puddings etc this is a recipé for disaster.

[Chancer]

[quote user="Gluestick"]

Mrs Gluey and I are absolutely delighted with our (Rather expensive!) Neff double oven.

As I write, I have stuffed toms and red peppers finishing: together with potato wedges.

In the small oven.

Does take time to come up to temp though, as it's conventional: but for certain dishes much better than a fan oven IMHO.

On a side issue, before doing the cuissine, in la belle: which will be the large major refurb job and a full rip out!), I need next trip to replace our exisiting free standing bottled gas jobby.

Where's the best place to source one in France? I only want a cheap one, 'cos I'll sell it soon after.

Any ideas peeps, please?

[8-)]

[/quote]

Leboncoin.fr

Search within Nord Pas de Calais or regions voisinées

Idem for selling.

[Gluestick]

Thanks, JRC.

I'll have a surf, later on.