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UK cooking appliances are a little different to US ones in that often people have 2 seperate parts:

The oven part, single ovens are usually rated at 3kW and can be plugged in. Double ovens 4-5kW would be hard-wired on their own circuit but should have an isolator above the counter.

The top bit where the pans go are often 7-8kW and are always hardwired, also with an isolator


The more traditional cooker, all in one is always wired on its own circuit, usually in 6mm on a 30a breaker/fuse Mine is like this and is 13.5kW

The cable used to connect the appliance to the outlet plate is the standard Twin and Earth cable

Traditionally, a special Cooker Connection Unit was installed and you would often see the cable going to this in trunking. Slightly more recently, another part, the outlet plate is installed behind the cooker

Both ways are available in the US, either separate oven and cooktop (hob) or combined in one unit.

Combined is popular because it tracks back to old wood stoves that had hot plates on top and a baking chamber next to the burner. Combined can be inconvenient because of the maximum of 50 amps, or in some cases 60 amps, of available current (at 240 volts). So this limits the size if the tops are all electric.

Separate is ultimately more convenient if you have the kitchen space to separate them. And the circuit requirements, being split, or more modest.

I personally do not like glass tops because of the difficult of getting quick high heat. Spiral elements are somewhat better, but not a whole lot. Gas has traditionally worked best for cooking, but electric is still useful for low simmering after fast heating.

The latest thing I found is the induction cooktop. It works with traditional steel woks when the induction surface is made rounded to match (these are called "induction woks"). Combined with high wattage (2.4kW to 3.8kW) this appears to do as well as a gas fired wok. It would need a 15 to 20 amp circuit at 240V, or 10 amps at 400V.

So my future kitchen is probably going to be a real mixup. But things should be on separate circuits not greater than 30A each at 240V (they frown on people getting 480/277V or 416/240V at home here).

Yep, except for some rare countries (I think Sweden) they always are and homeowners are not supposed to do any electrical work involving tools (i.e. beyond plugging and unplugging stuff or replacing light bulbs). So I guess if a range were damaged by miswiring the manufacturer could easily claim illegal installation and refuse to pay.
It is legal though to connect ranges via an appropriate 3 phase plug and I will certainly do so whenever I install one in the future as these plugs and receptacles are just much nicer to wire as the traditional cord outlets (ranges are considered portable appliances even though hard wired and have to be wired using a flexible cord whip and wall outlet with proper strain relief).

Edit: both separate and combined are available here. If separate usually the oven is plugged in (3.5 kW, within the limits of a 230V general purpose 16A circuit) and the hob is hard wired using 2 phases of a 3 phase circuit. Sometimes they only appear to be split but actually the hob is just fed via the oven and the oven gets the same feed as a combined range. Internally combined ranges usually have the top elements wired to two of the 3 phases and the oven to the third.

Johno,
I'd like you to clarify that power rating?
3kW seems a tad low for an "appliance" that has a grill element in it, over here a grill element can be rated as high as 5-6kW.
Don't get me wrong, I'm not trying to take you to task or anything, it's been a while since I fixed an oven.
I was always told the main reason for a stove having such a large supply cable, was because of the Grill element.

Hi,

It is only the single ovens that are 3kW, like this one: Oven

I guess I'm a bit out of date re US cookers then! Probably all those old films

That's typical of US ovens and ranges. Individual electric range elements in the US are typically between around 1000W - 2400W, (1200-1500W for a standard coil element) with the stove element around 3000W or so. A typical 40A 240V breaker will support 9.6kW total between them all.

Larger building sites can have 3-phase transformers instead of 110V CTE (Center-Tap Earth). The secondary is 63/110V wye, star point grounded, but no neutral extended, with single-phase 110V branches being distributed A-B, A-C, and B-C as required.

Cooking appliances have also become quite a lot more energy efficient in recent years than they used to be. However, the main thing is that modern kitchens tend not to use the traditional "cooker" i.e. double oven, grill + 4 hobs.

The current trend here is two single ovens mounted at eye level side-by-side rather than the traditional double oven.

Also, one that Paul might be interested in, ETCI banned the use of ring circuits to supply socket circuits in kitchens here in the most recent update to the Irish wiring regulations. For historical reasons, the ring circuit is far less widely used here than it is in the UK anyway, but even so it was permitted.

Rings can still be used, but only on low-power socket circuits i.e. to non-kitchen/utility room areas.

Seems like a sensible enough approach to me.

If someone has a reference to this, they might consider updating the wikipedia reference to Ring circuits.

http://en.wikipedia.org/wiki/Ring_main

They way our regulation system works, the new rules are phased in over a period of 12 months.

ET101:2008 (4th Edition) of the Irish National Rules for Electrical Installations became available on 06 October 2008. However, new installations may be constructed to either the 3rd or 4th editions until 30 September 2009. In the mean time the industry is supposed to re-educate itself about the new rules.

As soon as I get my hands on a copy, I'll reference the appropriate sections on here and on wikipedia.