I had been asked to carry out some work to replace ceiling and wall lighting in a lounge as the customer wanted to update the light fittings. 

On commencement of works I had noticed that there were 2 fuseboards.   While 2 fuseboards are not a rarity, as you would have them supplying different areas i.e. main house and outbuildings [all separate dwellings, independent of main house must have their own fuseboard].  On this occasion it was most unusual as the fuseboards were placed next door to each other and was to purely allow for increased usage in the house. In this instance, the better option would have been to increase the size of the fuseboard and have everything on one board.  

The old fuseboard was not RCD protected and the new fuseboard had been fitted with RCD protection. My findings had identified that the circuits had not been protected by the main RCD on the new board and had in fact been wired incorrectly.  The incorrect wiring meant that the mcbs [miniature circuit breakers] would not trip in the event of a fault on the circuit. I advised client that this would have to be rectified.  While the work was carried out by a 'qualified' electrician, I was very surprised to see this kind of incompetence.

So before I began changing the light fittings, I installed an RCD and rectified the incorrect wiring on the old fuseboard.  I then correctly rewired the newer fuseboard so that the mcbs were protecting the circuits.

With the boards now wired correctly the RCDs began picking up the earth faults and were tripping respectively. This was traced back to a faulty old double socket which was disconnected.

If I could advise anyone it would be:

• Please make sure that your work is carried out by a qualified, competent electrician. 

• Make sure to check the siret number. This can be done online and will show you exactly what the person is qualified to do.

• If you cannot check the siret, ask for the carte professionnelle. This has all the  information on the back of the card including work qualified to carry out.
  

It is not uncommon to find that you have 3 phase electrical supply in a French property, particularly in farms or buildings with industrial use, where you will need high current.  Most new installations [new builds and rewires] are now supplied in single phase. 

3 phase means that you have 3 live terminals and 1 neutral at the metre supplied by EDF and the fuseboard is a lot bigger. The supply comes in normally at a higher kVA i.e.  15kVA. This actually means that there are 3 lots of 5kVA [25A] on each phase and the current drawn must be balanced on each phase as overloading on one phase will potentially cause nuisance tripping.  

An electric cooker/hob, for example, draws a high current and is available for either 3 phase or single phase.  If your home is 3 phase then your cooker/hob needs to be installed as 3 phase.  Bearing in mind that a cooker/hob is 32A, the installation of the cooker/hob means that the current drawn will need to be balanced across all phases.

Unlike 3 phase, where there is a need to balance the load, with a single phase supply circuits can be freely assigned, ideally by a qualified electrician.  Please bear in mind that you need the right kVA for the size of your dwelling. The most common are:  6kVA,  9kVA,  12kVA and 15kVA and can only be determined and set by EDF.  The unit price of your electricity is affected by the amount of kVA. 

For example when we moved into our rented property it was set at 12kVA and not taking advantage of tariff bleu creuse for the hot water tank.  There are 2 of us at the dwelling with a 200litre water tank, we have very few high drawing appliances  and no electric heating. We asked EDF to reduce the kVA to 6 and apply tariff bleu creuse to heat the hot water tank over night.  Our trimester bills are extremely manageable.

To demonstrate an example of cost differences across kVA, the image below was sourced from www.frenchproperty.com and shows the annual standing charges, base rate and night tariffs of each kVA. Figures shown are as of July 2012. 

This does not necessarily mean that this will apply to all customers, as is dependent on the size of your house, your electricity tariff [of which there are many], your appliances, size of water tank, if you have electric heating and the general state of your electrical installation. 

We hope this provides some clarity about 3 and single phase and if you have any questions, you know where we are.