Converting 3 Phase to Single Phase in France

[jakelepeg]

I have a 3 phase supply to my farmhouse in France but really have no need for the higher voltage available.

Until 15 minutes ago I had no idea as to how the 3 phase worked but now, after searching the net, have a lttle better understanding.

I would like to install a new single phase fuse box next to the existing 3 phase fuse box to supply power to an extension I have built and, of course, I can pick up a supply from one phase on the old box. However, I have been reading that individual circuits of 240v should be carefully balanced. It's here I'm a bit stuck.

Is it possible to convert the old existing 3 phase box to supply only single phase to the new box without having to worry about balancing the whole lot and, in fact, possibly only be capable of supplying single phase from either the old box or new?

 

[plugwash]

What is the incoming supply like (e.g. what rating is the service fuse and any other incoming current limitation like)?

also what is your existing board like, is each position permanently assigned to a particular phase or are things more flexible than that?

 

[briwire]

If you have spare ways in your existing 3 phase board I would leave it and use that. There is nothing wrong with using a 3 phase board to supply nothing but single phase circuits. It is common practice in factories to use 3 phase boards to supply sockets on different phases, lighting on different phases etc. You just have to take precautions where they are mixed, eg sockets in the same room or more than one phase in a light switch.

As for balancing, it's in an ideal world. If you were starting from scratch and designing an installation, you would spread thing as evenly as possible between the phases. But in your case, try to assess roughly what is being used on each of the phases, and if one is lighter than the others, take your supply from there. Any out of balance current is just carried in the neutral to your board, so it won't cause a massive problem.