ECN Forum Forums General Topics of the Trade Non-US Electrical Systems & Trades 400V - scary or not?

From what i've seen of French cookers/stoves sold here they're wirable for either 230V or 400V. I think the way they actually work is to split the elements over different phases they're actually 230V but different parts of the cooker will be supplied by different phases sharing out the load.

Our hob for example came with a full 5-wire lead on it and if you're connecting it in Ireland to 220/230V you simply connect all of the lives together using a specially supplied junction box (3 X lives on a bus bar) to a single 220V live. So at the very most all it's doing is shifting each plate/group of plates to different phases.

Yes, now that we have many models being sold in the same form right across Europe, I've seen many such ranges arranged in this way. All the individual elements are 230V wired phase to neutral, but distributed between the 3 phases.

When we use them in a British domestic kitchen we just strap the L1, L2, L3 terminals together.

I've also seen quite a few older U.K. made ranges (say early 1970s) which were wired internally to a single pair of L1 and N terminals, but the terminal block had empty positions clearly labeled L2 and L3, which must have been used for export versions.

If you have ever cut a 3phase+Earth cable that was supposed to be dead, and had your cable-cutters wrecked by the flashover,
my case in point.

I really can't see the advantage of 3-phase in anything other than industrial situations where the smooth starting and running of large-scale electric motors is a concern. 230V single phase supplies quite obviously can and do work perfectly effectively and safely in UK/Ireland for everything including heating and cooking. 380/400/415 volt 3phase systems just add extra shock hazzards and excessively complicated wiring for no good reason.

In heavy load domestic situations here where electric space heating is used a second 80 - 100amp supply (not necessarily from a different phase) is sometimes added specifically for that purpose. The heating system would be metered seperately, fused seperately and treated as a completely seperate supply.

The IEE in Britain seems to have always been quite opposed to 3-phase in residential environments. Where 3-ph is used (and it would be a VERY big house, maybe a large guest-house or something like that), then they have rules regarding such things as the placement of phase barriers in boxes, ensuring that all sockets in one room are on the same phase, etc.

Our friends across the Big Pond may well feel uneasy at residential being 240V to ground, nevermind 415V 3-phase!



[This message has been edited by pauluk (edited 03-21-2003).]