/ Electric cooker wiring

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jon on 26 Feb 2013
This might seem obvious to most, but I'd rather be sure. We inherited a freestanding cooker (electric oven, and hob with three gas rings and one electric element) with this house two years ago. It was plugged into a normal wall socket with a normal plug and has never been a problem. There is however a dedicated electrical supply for the cooker in the wall just behind it and I'd like to connect the cooker to that to free up the normal socket for another appliance. So, two questions:

1. Having taken off the plastic plate in the wall I find the (very thick) wires ending in dominos - I imagine this supply has never been used. I would like to fit a socket so I can unplug and move the cooker if I need to. Do I have to use a special socket and plug for this or could I fit a normal one (given that there have been no problems with it being plugged into a normal socket up to now)?

2. The wires in the wall are red, blue and green/yellow. I assume that I must wire the socket so that red goes to brown, blue goes to blue and earth goes to earth?

Yes, I really am that nervous. Thanks.

pwo - on 26 Feb 2013
In reply to jon: I'm no electrician but wiring a cooker into a normal ring main is just plain stupid. You're right to ensure that the cooker is wired to the correctly rated circuit (32A). Don't even attempt to wire a 32A rated wire into a 13A socket.
mkean - on 26 Feb 2013
In reply to jon:
Hi Jon.

I assume this isn't English wiring?
jon on 26 Feb 2013
In reply to pwo:

The existing plug on it is a sealed unit and therefore it must have been supplied with it. It is marked 250V 16A.
jon on 26 Feb 2013
In reply to mkean:

No, you're right, it's French.
jon on 26 Feb 2013
In reply to pwo:

Err, to be clear, I've no problem with going out and buying a special socket, I just want to be clear in my own mind. The fact that it was already being used for some years in a regular socket has just rather confused me. In our other house I remember the electrician installing a special socket.
mkean - on 26 Feb 2013
In reply to jon:
No, you're right, it's French.

Eek, run away! Every French property I've stayed in has wiring which would be described by an English electrician as being somewhere between "interesting" and "an absolute deathtrap". It is difficult to make good reccomendations without knowing a bit more about the wiring of the property.
richyfenn on 26 Feb 2013
In reply to jon:

Should be fine. Get a wall socket that will screw into where the cover was, and attach the wires to the socket in the correct places. Maybe try and find a socket that is marked for 16A rather than the usual 13A?

As long as there is a 13 amp fuse (not a nail!) in the plug then nothing can go wrong other than the fuse blowing (assuming you wire it up correctly).

Red/Brown = L
Black/blue = N
Yellow&Green = Earth.
SteveCarter - on 26 Feb 2013
In reply to jon: Cooker obviously ok to plug into normal 13amp socket... you'll need to downgrade the existing dedicated cooker point, behind cooker, to 16amp at the fuse board.
SteveCarter - on 26 Feb 2013
In reply to scarter: ...but don't open the fuse board if you're not competent or you may kill yourself.
jon on 26 Feb 2013
In reply to mkean:

Ha, yes! The house is very old but was completely rewired about five years ago so it's not ancient stuff. As far as I can tell it looks of a similar standard to our other house and certainly hasn't provided any scares... yet. But it's not the wiring I'm worried about, just whether I can fit a regular socket to the fat wires or a special socket.
SteveCarter - on 26 Feb 2013
In reply to jon: Better to snip plug off the cooker and wire direct into cooker connector behind cooker.
SteveCarter - on 26 Feb 2013
In reply to scarter: ...but would need downgrading at fuse board end also.
jon on 26 Feb 2013
In reply to scarter:

> (In reply to jon) you'll need to downgrade the existing dedicated cooker point, behind cooker, to 16amp at the fuse board.

Do you mean changing the switch/circuit breaker in the fuse board? Looking at it, it's marked MFS 732 C32. All the others are marked MFS 720 C20. I presume I can leave the fat wires as they are?

> ...but would need downgrading at fuse board end also.

Ah, I hadn't seen this post. That is what you mean.
SteveCarter - on 26 Feb 2013
In reply to jon: Yep to do it properly, change circuit breaker at the fuse board and wire direct into cooker connector... you could just fit socket behind cooker but you'll struggle to get 6mm cables in.
jon on 26 Feb 2013
In reply to scarter:

OK, thanks. Out of interest, what would happen if I didn't change the circuit breaker?
SteveCarter - on 26 Feb 2013
In reply to jon: Could damage the cooker... The circuit breaker is doing the same job as the fuse in the plug, it's protecting the cooker.
SteveCarter - on 26 Feb 2013
In reply to scarter: ....and the circuit itself
richyfenn on 26 Feb 2013
In reply to scarter:
> (In reply to jon) Could damage the cooker... The circuit breaker is doing the same job as the fuse in the plug, it's protecting the cooker.

Its not protecting the cooker, it's protecting the cable in the wall! If you cut the plug off and wire it in you will need to change the fuse at the fuse board. If you leave the plug on and fit a socket (it is possible to fit fat wire, I've done it) then you don't need to change anything at the fuse board.

Fuse at the fuse board protects the cable up to the socket. Fuse in the plug protects the cable up to the cooker. Get it wrong and your house burns down.
jon on 26 Feb 2013
In reply to richyfenn:

> Fuse in the plug protects the cable up to the cooker. Get it wrong and your house burns down.

Ah. No fuses in French plugs! I guess I'll have to change the circuit breaker. I don't want the house to burn down.
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SteveCarter - on 26 Feb 2013
In reply to richyfenn: I agree, circuit breaker is protecting circuit(cable in the wall) but also protecting cooker.... the existing cooker circuit has a cooker connection point behind the appliance(should also have cooker switch)... this is for sole use of oven/cooker and is meant to be hardwired.
SteveCarter - on 26 Feb 2013
In reply to jon:... the house won't burn down... the breaker would trip first...
jon on 26 Feb 2013
In reply to scarter:

Hardwired = cutting the plug off and fixing the wires straight into the dominos?

So if doing this I simply have to change/downgrade the circuit breaker? I don't need to change the wires for thinner ones?

Don't think there's a cooker switch - don't know what I'd be looking for, but there's nothing other than wires ending in dominos in the wall and a circuit breaker at the other end. Everything is neatly labelled and that's all I can see.
SteveCarter - on 26 Feb 2013
In reply to jon: Cables are ok... but if it's definitely a cooker circuit then there will be a cooker switch somewhere... big red switch with cooker on it...?
jon on 26 Feb 2013
In reply to scarter:

No there isn't. Everything is accounted for on the circuit breaker board. What would it do if there was one?

The circuit breaker is labelled 'cuisinière' and there's nothing else. This is France, of course...
SteveCarter - on 26 Feb 2013
In reply to jon: There may be a reason the cooker was plugged into a wall socket...? Maybe cooker cable damaged or disconnected..? You'd need to test... and cooker switch should be present.... again if you're not sure or competent, don't mess with electric, it may kill you.
SteveCarter - on 26 Feb 2013
In reply to scarter: Cooker switch isolates cooker... maybe not a regulation in France...?
jon on 26 Feb 2013
In reply to scarter:

I suspect it's just plugged into a regular socket as 1) the cooker came equipped with a regular plug, and 2) the house was previously owned by a Parisian woman - they're all-knowing and never wrong, you know! But you're right, maybe I should find a man who knows. Thanks.
Neil Williams - on 26 Feb 2013
In reply to scarter:

I have a feeling that it being plugged into a 15A socket is not unusual in Europe.

Would be inclined to consult a local electrician. Many other things are different as well (e.g. no ring mains, which is probably a good thing as ring mains have a nasty invisible failure mode[1] - maybe one day we'll abandon them in favour of 20A radials as well, given that the ring main only came about as a result of a copper shortage).

[1] A break in the ring can result in a loading of over 24A on one side, which is all the 2.5mm cable is normally designed to take, and is not protected by the usual 32A breaker. I suppose it's not something that is all that likely these days as most stuff you have plugged in is low-power electronics rather than 2 bar electric fires and the likes that used to be common.

Neil
interdit - on 26 Feb 2013
In reply to jon:

Job 1 - Check your tableau and find the disjoncteur that for the circuit that you believe is a dedicated cooker circuit.

Hopefully it is a 32A one. If it is a 20A, then you may substitute 20A equipment in my comments below. If it is 16A, then its not a 'cooker' circuit and you must not do any of the following!

Job 2 - Buy http://www.bricodepot.fr/odos/node/468306 which is a 32A rated socket (and is usual for a cooker socket).

Job 3 - Buy http://www.bricodepot.fr/odos/node/468328 which is a 32A rated 'cooker' plug. Fit it to your cooker and plug it in.

* an alternative to Job 3 is to fit your cooker with a normal 16A plug and use a cooker socket adapter http://www.castorama.fr/store/Adaptateur-Male-20A-en-femelle-16A-blanc-PRDm841354.html?navAction=jum...



Some things NOT TO DO:

DO NOT wire the cooker directly into the dominos.
To do this you must have an inline 32A rated double pole isolator. The French do not like doing this with a 'cooker switch', so they use a 32A plug & socket.

DO NOT fit a standard (ie. 16A rate 2p + t) socket into a circuit that is fused for 32A (or 20A). The socket can overheat and burn your house down.


In France they rarely worry about which is live and which is neutral, but I do and so would wire up my plugs and sockets to present the live on the right hand pin.
You are correct:
red -> brown
blue -> blue
earth -> earth (Yellow / Green)

You can pay someone to come and test it all afterwards and tell you whether it conforms or not. You have to do this before you sell the property anyway.


L'installation électrique. (in the Comme un Pro series) is very often the recommended text for DIYers in France:

http://www.amazon.fr/gp/product/2212134509/ref=oh_details_o01_s00_i00?ie=UTF8&psc=1

jon on 26 Feb 2013
In reply to interdit:

Ooof! Thanks for that.

The disjoncteur is marked MFS 732 C32 (which I take to be 32A). It is clearly labelled 'cuisinière'. It is the only disjoncteur with very fat wires and these come out behind the cooker.

The socket and plug which you linked are indeed what our electrician installed in our other house.

The cooker is already equipped with 16A plug so I'm inclined to go along the lines of your alternative 3, ie get an adapter. I'm a little confused by this however as the adapter you linked is 16A > 20A into a 32A socket protected by a 32A disjoncteur, but then you say DO NOT fit a 16A socket into a circuit that is fused for 32A or 20A? If I did this wouldn't the plug risk heating up in the same way that a 16A rated socket might?
interdit - on 26 Feb 2013
In reply to jon:

> MFS 732 C32 (which I take to be 32A). It is clearly labelled 'cuisinière'

Cool. That's the correct item.

> The socket and plug which you linked are indeed what our electrician installed in our other house.

The regs now say one must be installed in every new house or complete rewire.


The 'adapteur' is a consumer item, as is your cooker.

You can choose to plug it in or not. It is not covered by the normes for electrical installation in your domestic property.

You can plug whatever you want into a socket. Its a free world.
What you can't do is wire up the house incorrectly.

The fact is, if your existing 16A cooker with its 16A plug and 16A cable shorts then it is going to take considerably more than 32A and will trip the disjoncteur very quickly. It is safe.
After all, you plug your 5A table lamp into a 16A socket every day?

If however you fit a 16A socket to the 32A circuit in the location that is obviously for a cooker then someone may be tempted to wire up a 7kW double oven using a matching 16A plug.
A 6kW oven will draw a max of around 25A.
Your disjoncteur will not trip, your thick wires (prob 6mm sq) will be safe and will not overheat. Your 7kW oven will be fine as it and it's wires are rated for this.
Your 16A socket and plug will be running at over 150% of their rated amperage. They will probably set on fire.

(Amongst other design considerations, a 16A socket will not have suitable clamps for the size of cable that is in your wall. Even if you get them to fit you will not have a high contact surface area. The current is forced though a tiny metal-metal contact area heating it up.)

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