Single phase electricity supply better than 3 phase?

We think that at some point the barn was used for something as it had two apartments installed on the first floor but previously it must have had some agricultural usage.

This is getting a bit confusing!

We had a problem a few years ago when the TV caught fire and although all the light switches in the living room were off the lights were still dimly on so we were a bit worried! Our french electricity man fixed it and the supply has been OK ever since but I am worried about the supply as it was installed by the previous owners over 30 years ago. Some switches seem to work nothing and some sockets are dead.

Blimey! That's a bit frightening. EDF installed a new post with a transformer a few years ago when 2 new houses were built to the rear of us. Our supply goes all around the field opposite and ends up with us via our neighbours who run a wood cutting business so our supply can be a bit up and down sometimes. They are proposing to join us as well to the transformer and I have been advised that it would be better for us to go onto single phase when they install the new line.

Good points well made :-) I've always disliked 3ph domestic supplies for these & many other reasons. all domestic stuff works on single phase so balancing the loads can be a real problem with some French supplies of varying voltages. I've measured between 200 & 243 volts on my supply before EDF renewed the overhead supplies to our sector. There must be lots of dodgy ancient supplies out in the sticks where old cables & transformers can't keep up with modern living.

Hi Kent if you get a 3 phase inverter to run your lathe from single phase you'll get the benefit of variable speed to and reverse at the flick of a switch. Not that expensive imo. Try Transwave converters www.powercapitors.co.uk

Going to do the same thing to my Boxford eventually............

Kent. you can usually reverse a single ph brushless motor by swopping the capacitor wires to another terminal.

I had considered that, Vic, and I do have a 3hp single phase motor to hand but, ⓐ I'm not sure if it's reversible - and it needs to be, and ⓑ it's a bitch to get at and, because of duff knees, I can't kneel down to work in that cramped space, certainly not for any long period - but thanks for the suggestion.

I think that some of the Colchesters had dual system motors and circuits but I don't know if this is one of them; needs a specialist to check that out. But anyway, it's none to high on my list of my 20,000,000 things to do as I have other machines that can do some of the jobs. It's just that I quite fancied building a largish stationary steam engine. I have some castings for a Stuart Turner 6a. Now let me see - how high is that amongst the 20,000,000 things…

We had 3-phase fitted to our 6 bedroom house when we re-did it 8 years ago. This on the advice of our electrician, but with the following unintended consequences :

1) CPL (HomePlug) ethernet modules have trouble talking across phases, and frequently won't work at all unless they're on the same phase

2) in the event of an outage of a phase, you will still have 2/3 of your appliances and lights etc when your neighbours may well be in the dark, BUT

3) if the outage is on the neutral, your neighbours will be in the dark, but you may be ON FIRE. This happened to us in January last year, and the resulting imbalance across the phases cost us 7k€ in lost appliances (computers, microwaves, hi-fi etc. but an amplifier and a wall-wart transformer were smoking and would have set the place alight if I hadn't shut everything off straight away. Pretty alarming with a house full of kids at night. Needless to say, EDF stone-walled us and OUR insurer wound up paying. (The déjoncteurs are only designed to break the circuits on surges like shorts, not percentile increases in current such as this, so no protection.)

On balance I'd stick with monophasé unless you have a particularly strong reason for not doing so. Hope this helps.

They actually have 2 phase supplies for this sort of thing which surprised me. I recently tried to get a huge 3 ph supply to an English property of ours in a residential area for a prospective pottery but 2ph was all that was available .

Kent. Can't you simply change the motor or possibly get it rewound for single phase? For interest the voltage of each phase on a multi phase supply is the total voltage divided by the square root of the number of phases eg. 415v 3ph = 415/1.732=240v per phase. This is why it's possible to split the phases to give 3 x 240v supplies. I recently helped a pal change his 3 ph fuse boards when EDF gave him a single ph supply as part of a new overhead cabling scheme. All went fine except for when we tried to reconnect a multi switched relay enabled corridor lighting circuit which had been wired, we think, across 2 phases & tripped the supply every time a light switch was used on the new single phase supply. That was a swine to sort out.

My understanding of the UK setup is that in residential areas, the 3-phase supply is split between the two sides of the street, resulting in a 240v supply to each property.

Hi Kent if you get a 3 phase inverter to run your lathe from single phase you'll get the benefit of variable speed to. Not that expensive imo. Try Transwave converters www.powercapitors.co.uk

Going to do the same thing to my Boxford eventually............

Last year we had all the external cabling changed from the supply post to the house and also a new digital meter etc installed (the old meter and all wiring was very dangerous). ERDF provided a Devis for 450 Euros, the work was done within 3 weeks and took 1 morning and they made an excellent job. All the old cable was slightly frayed and had come away from the securing points on the external wall under the eves and so the fixed the 50 mtrs of new cable properly and now it is all nice and neat and more importantly, safe.

Rgds, Mike L

You can always change the tariff of electricity used or install a gas hob with bottled gas in one of the properties which could solve your problem.

Hi Neil, I'm curious to know what advice you receive both from EDF and from this forum because, although we only have single phase in this house, I brought a 3 phase-powered Colchester Student lathe with me from our last UK house and I was wondering whether to get a single to 3 phase converter (expensive) or whether it would be more logical to get EDF to run 3 Phase from the nearest post, which is only at the side of our house. Dunno…

It may, perhaps, be interesting to note that, when I built that, aforementioned, last UK house, I found the main underground cable to the nearest sub-station right next to it, so I asked the UK EDF if I could have a 3 phase point in my built-in workshop. They said no prob' and, not only that, but I could run the rest of the electrics in the workshop from one phase and run the house electrics from another - which I did. As long as you don't do anything completely bonkers that would mix those two phases it's not a problem - so I was told - and that seems to be the case.

No doubt someone will tell me I'm wrong about this but my understanding is that each domestic single phase comes off one phase plus the neutral of the 3 phase system anyway. Perhaps you could keep your 3 phase system - as long as it's not costing you any more to do so - and use one phase for your place and another phase for the guest accommodation. Perhaps that would make it easier to isolate your cutting out problem - and fit individual higher rated breakers where necessary.

Tis just a thought. Good luck.

Also depends on what you're getting at the moment.

We are on 3 phase totalling 9KVA (3 x 3KVA). On asking EDF for an upgrade as that barely powers a kettle, we were offered either 12KVA single phase or 18 (3x6KVA) 3 Phase.

So we're going with the 18KVA 3 phase and 'managing' the consumption.

Last year I visited EDF to query my high bills; they sat me down and ran through,as you have done here, our approximate usage, equipment (pool pump, water filters, number of fridges and type etc) and gave us an estimate. Just as high, actually. My point is that you can do the same for what you require in your property, including the info about the cooker problem. They should be able to run a diagnostic and tell you immediately what you need.
Our pool man thought we didn't need 3 phase, EDF said we did.

Hi, We have a 6 bedrooom gite that runs two hot water tanks, two electric ovens (probably not both on at the same time,) two dishwashers and two washing machines, plus the pool pump, all on a sinle phase, 9kw supply - never had a problem. Hope this helps.

From experience, ERDF install what THEY think fits the bill! if the house is just for a house; 1ph is all you get, if it's a Breton Longère (terrace of three units of two up two down with any land attached) you get three phase... there is no real distinction between habitation, farm, industry etc..... my old office on an industrial estate was single phase!!

If its a renovation project, three phase is very useful.... possibility of having the main house on one phase and then each of any gîtes etc on their own phases

Then comes the details of the contract..... whatever you do.... keep away from any EJP contracts

We have the same arrangement as you Mike and we too run a large range and other cookers between two gites and our main house. We have 18kw supply which is split in to 3 x 6kw and my husband as a qualified electrician was careful to decide what went on each of the phases, taking in to consideration what was likely to be used and when and we have had no problems since. It is usually the old properties that have three phase, like old farms which can still today use farm machinery with the tri phase