If it comes with a plug (or says that a 13A plug is acceptable in the instructions), then it can be put on your ring, assuming you are correct about the current appliance loading on the ring.
Christian.
Thanks.
The plug bit I understand?
If it doesn't come with plug, can it be connected to a FCU off the ring main through an appliance connector? At what power rating would I expect to have to have a dedicated cooker circuit?
I can get no other information other than the 3100W figure for now. That's a tad over 13A @230V, so it seems 'close'.
Not usually. If it is suitable for connection to a socket, EU law states it should be supplied with a plug. Only appliances that could be supplied with a plug are suitable for an FCU. Therefore, it is a reasonable assumption that no plug supplied means no ring suitability. This presumption appears correct in this case as the load is actually fractionally over 13A. If it was 3100W/240V rated, I would say that it probably was suitable, as that would be fractionally under 13A at both 230V and 240V.
I would run the circuit using 6mm cable, but connect it to a 16A MCB. The
3100W/230V appliance needs a 16A MCB, but if you are running a cooker circuit, make it 6mm so that it could be upgraded to a 32A cooker circuit in case some muppet wants an electric cooker in the future.Christian.
Did you forget to reply?
| Windy Miller wrote: | > We're looking at a new dual fuel cooker. There's no dedicated cooker | > supply in our kitchen so it has to go on the kitchen ring, either on a | > FCU or a plug. The kettle is the only other high power device on the ring. | >
| > One Zanussi model has a power rating ('total rating' in their language) | > of 3100W at 230V. Is this just over the limit or can this be connected | > to our ring main?
The *actual* voltage in the UK is still 240V so 3100W / 240V is 12.91 amps so it is OK. If you run it on the rated voltage of 230V it will take slightly less current than that.
I have run 3100W kettles on our ring main for years without problems, and the come with 13 amp plugs attached.
The *actual* appliance rating in this case is 3100W/230V which is over
13A. Increased the voltage to 240V and the current goes over 14A and power to 3375W.MBQ
But if it's rated at 3100W at *230V* like the OP says, it will actually be
3375W at 240V, and take 14 amps. Even at 3100/230 it uses more than 13 amps.Whilst it may physically work without blowing fuses, it is very marginal and potentially dangerous - and cannot be recommeded. As others have said, if it is capable of running off a 13A plug, it would have been supplied with one fitted.
On Tue, 08 Nov 2005 10:20:23 GMT someone who may be Windy Miller wrote this:-
Has to go? You could install a circuit for a cooker to the kitchen. This would allow future occupants a choice over the sort of cooker they use. The supply should be at least 30/32A, but being old-fashioned I prefer 45A (which means expensive cable and equipment compared to the lower rating). You can do the work yourself in Scotland, provided you are "a suitably qualified electrical engineer" able to design, install and test it to the Wiring Regulations. You may need to be able to defend yourself in court if you do so, the alternative is to get someone to do it. Down south things are different.
What follows is from memory. I have not looked it up and it is worth exactly what you have paid for it. Someone may correct me.
Large cooking appliances must be provided with an isolating switch within 2m of their location. That is because, even if it can be moved, it is considered to be fixed equipment.
A 13A fuse will not blow rapidly at the current you have given. However, it (and possibly bits of the FCU) will run warm, perhaps rather warmer than designed. Even if you don't eventually set something on fire it is likely to discolour.
In ye-olden days it was a standard arrangement to connect fixed equipment to a ring main with a circuit breaker not exceeding 16A. However, the connection of large loads to ring circuits has been discouraged for a long time. Partly this is because it robs the circuit of capacity for other loads. It may be that in your particular circumstances you can justify such a connection, but you will need to document it and I would only do so as a very last resort. You would then use 20A rated equipment from the circuit breaker to the cooker outlet.
No. If its marked 13A @ 230v then its really 13A @240v, depsite how odd that sounds. 230v is the legally accepted official description of our really 240v supply. If it says 13A, its 13A.
Can you put a 13A cooker on a ring main? Of course. Can you put a 15A cooker on a ring main? Of course. But possibly not at the same time as a 200A arc welder.
NT
| | Dave Fawthrop wrote: | > On 8 Nov 2005 02:41:48 -0800, "urchaidh" wrote: | >
| > | Windy Miller wrote: | > | > We're looking at a new dual fuel cooker. There's no dedicated cooker | > | > supply in our kitchen so it has to go on the kitchen ring, either on a | > | > FCU or a plug. The kettle is the only other high power device on the ring. | > | >
| > | > One Zanussi model has a power rating ('total rating' in their language) | > | > of 3100W at 230V. Is this just over the limit or can this be connected | > | > to our ring main? | >
| > The *actual* voltage in the UK is still 240V so 3100W / 240V is 12.91 amps | > so it is OK. If you run it on the rated voltage of 230V it will take | > slightly less current than that. | | The *actual* appliance rating in this case is 3100W/230V which is over | 13A. Increased the voltage to 240V and the current goes over 14A and | power to 3375W.
The 230V rating in the UK is just because of the EU rules. :-(
You snipped my experience of using a 3.1kw kettle for years without problems, so I have repeated it.
| In an earlier contribution to this discussion, | Dave Fawthrop wrote: | | >
| > The *actual* voltage in the UK is still 240V so 3100W / 240V is 12.91 | > amps so it is OK. If you run it on the rated voltage of 230V it | > will take slightly less current than that. | >
| But if it's rated at 3100W at *230V* like the OP says, it will actually be | 3375W at 240V, and take 14 amps. Even at 3100/230 it uses more than 13 amps. | | Whilst it may physically work without blowing fuses, it is very marginal and | potentially dangerous - and cannot be recommeded. As others have said, if it | is capable of running off a 13A plug, it would have been supplied with one | fitted.
My 3.1kw kettles come with a plug.
No. If it is marked as 13A @ 230V, it means just that. The same appliance would draw 13.6A at 240V.
Many larger heating appliances, such as electric showers show a 230V rating and a 240V rating. They will be different.
Christian.
Yes. And a 3100W at 240V would be allowed to do this. It is a 3100W/230V appliance that could not.
A 3100W/240V would draw 12.91A at 240V and would draw 12.4A at 230V.
Whilst a 3100W/230V appliance at 240V drawing 13.5 would actually be safe enough in practice, it is not permitted to design a system with a built in overload.
Christian.
A kettle is a short duty cycle item but a cooker is not, that makes quite a difference.
No, the 230V rating is a 230V rating. At 240V the power consumption will be higher.
Look up the specs of a few high power items such as showers (e.g. MIRA website is easy to use) or hobs where you'll find different values or a range of values quoted for voltage v power.
MBQ
In article , Christian McArdle writes
V**2 mate so 14.1A for a heating appliance.
But R will probably increase with the higher temperature from the higher current, so it might not grow quite that much!
On Tue, 08 Nov 2005 14:26:40 +0000 someone who may be Dave Fawthrop wrote this:-
How long does it take to boil the kettle when it is full? How often is it boiled in a day?
A fairly common mistake in house wiring is to think that a 3kW immersion heater can be plugged into a ring main using a plug and socket. The plug in particular is not really designed to feed such a load for long periods of time (even a short immersion heater may be on continuously for the best part of an hour if the cylinder is cold and the thermostat set high). The result can be at best overheating and at worst a fire. For a long time it has been recommended that special consideration is given to such heaters and a dedicated circuit is strongly advised.
While an oven (I assume electric oven(s) and gas hobs in the cooker) is unlikely to take as long to warm up, it still has a duty cycle more onerous than a kettle has. If it really isn't possible to provide a dedicated circuit then connecting it to a ring circuit needs care and a thorough understanding of what one is doing. Someone who asks the question may well not have enough understanding.
V**2 for the power, not the current, assuming constant resistance.
i.e.
230V/13A = 17.69 ohms (and 2990W)240V @ 17.69 ohms = 13.56A. (and 3256W)
Christian.
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