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.

Last edited by Texas_Ranger; 11/28/08 09:41 PM.