Phase and neutral (France)

[beneix]

Just moved into a property in France. The electrical installation came with a certificate that all was in order. So far, I have discovered the following:

1. A light circuit is wired 2-way when it should be three-way – the third wire between the light switches is missing (so not easy to rectify).
2. Some sockets have phase and neutral swapped. In these sockets, the voltage between earth and neutral and between earth and live is around 110V AC.
3. In some sockets, my multimeter shows 0.7-1.5V AC between neutral and earth. In some sockets, it is 10 or 15V AC.

The first one I can see not being something that I can complain too much about, as it isn't a safety issue. Swapped phase is clearly something that should not have allowed a clean certificate, but what about the aberrant voltage between earth and neutral (3) – what does that indicate?

 

[ChrisEll66]

1 Are you sure it's not via a little thing in the switchboard? France uses teleinterupteurs more than 3 way switching.
2 There really isn't a rule on live - neutral - in sockets - a vaguely followed standard is a better way to view it in France. If it's a modern installation it will be both RCD protected and double pole MCB - it's really not important.
Sockets are normally daisy chained - so follow the chain. Do the sockets you think have 110v actually work and are you reading 230 on the next socket? You can get low readings with poor connections - but it will continue down the chain.
3 10+v is highish - but not uncommon. House has its own earth I assume so it's not that unusual. Check your earth resistance possibly

 

[EFLImpudence]

1. A light circuit is wired 2-way when it should be three-way – the third wire between the light switches is missing (so not easy to rectify).

What do you mean?

In the UK we use the terms two-way and three-way to denote the number of switches that operate the same light(s) - nothing to do with the number of wires..

 

[sparkymarka]

You can get 10v ac on an alarm wire between earth and the alarm wire ….it’s just induced ac voltage …

 

[beneix]

What do you mean?

In the UK we use the terms two-way and three-way to denote the number of switches that operate the same light(s) - nothing to do with the number of wires..

I mean that a two-way switch requires three wires, and my two switches only have two wires coming in to them. Depending on the position of one switch, the other either can or can't operate the light.

 

[Ragnar_AT]

I‘d assume flexible conduit that you can pull additional wires through. The French love easily accessible wiring (including rather unsightly trunking all over the place).

Regarding the sockets showing 110 V neutral to earth I‘d have someone check if they’re properly earthed.

 

[Pat ex]

I mean that a two-way switch requires three wires, and my two switches only have two wires coming in to them. Depending on the position of one switch, the other either can or can't operate the light.

France does not use the same technology as UK for 2-way and intermediate switches. They have what's known as come-and-go (Va et Veint) switches, which do not need the UK style 'strappers' between switches. I don't think it's possible to buy the intermediate switch, which is different to the 2-way switch.
As ChrisE1166 explains, there are teleinterupteurs. The switch sends a message to the teleinterupteur which controls the light.
If you have UK style 2-way switches fitted on such a system, you will experience problems. You need to change them for French style.

Also, as Chris1166 explains rural houses have their own earth rod into the ground.

 

[JohnD]

(Va et Veint)

va-et-vient

 

[Pat ex]

va-et-vient

Quite, a typo +.

 

[beneix]

France does not use the same technology as UK for 2-way and intermediate switches. They have what's known as come-and-go (Va et Veint) switches, which do not need the UK style 'strappers' between switches. I don't think it's possible to buy the intermediate switch, which is different to the 2-way switch.
As ChrisE1166 explains, there are teleinterupteurs. The switch sends a message to the teleinterupteur which controls the light.
If you have UK style 2-way switches fitted on such a system, you will experience problems. You need to change them for French style.

Also, as Chris1166 explains rural houses have their own earth rod into the ground.

Thanks, hadn't heard that term before. A quick google suggests it still requires the same common wire between the switches as a UK 2-way, though:

(https://duckduckgo.com/?q=Va+et+Veint&t=ffab&iax=images&ia=images&iai=https://media.ooreka.fr/public/image/340503-comment-brancher-un-va-et-vient-1--panorama-12327868.jpg)

What am I misunderstanding when I say that the two separate 2-way switches require a connection between them, i.e. L+N+Com?
By the way, the property in question is an apartment. A neighbour told me there is no earth, but I am not sure he knows what he is talking about.
The potential between different wires varies from socket to socket:

	Potential btw. L & "E"	Potential btw. N and "E"	Potential btw. "E" and a water pipe
Socket 1	75V AC	30 V AC	1.2V AC
Socket 2	235V AC	1.7V AC	1.7V AC
Socket 3	1.4V AC	235V AC	0.2V AC
Socket 4	110V AC	109V AC	2.4V AC

Is this what is referred to in the comments as floating earth?

 

[EFLImpudence]

In the diagram, there are no Neutrals at the switches.

The only Neutral is the blue wire from the lamp back to the supply.

What are you meaning by "socket" 1 to 4?

 

[beneix]

In the diagram, there are no Neutrals at the switches.

The only Neutral is the blue wire from the lamp back to the supply.

Yes, quite like a diagram of a UK 2-way switch:

What are you meaning by "socket" 1 to 4?

I have many sockets/outlets in the apartment. The table shows how some of them measure.

 

[EFLImpudence]

I have many sockets/outlets in the apartment. The table shows how some of them measure

Oh, ok.

I thought you were referring to measurements at the switches.

 

[EFLImpudence]

In that case:

It would appear you have reversed polarity at socket 3.
Sockets 1 & 4 L to E something wrong.

L to E should always be ~230V
L to N should always be ~230V

N to E (or E to pipe if earthed) should always be very low Ohms - and very low Volts.

 

[Pat ex]

Two-way switches in France can be wired just like the same in UK.
Here's two examples, but both require two wires between the switches.

How to add a 2nd light switch

Hi all. I want to add a 2nd switch to a single light. The only switch is at the far end of the hall. Can anyone offer any guidance or know where I can find out how to do it ? Thanks !

www.survivefrance.com

For intermediate switching there aren't any intermediate switches available. The French use the teleinterupteurs.
Here's an explanation.

Explaination Of French Intermediate Switching!

Help!! trying to complete a job, in London for a French couple. At a late stage, two floors first fixed, the client wants to use a French make of accessories, Arnould (off shoot of Legrand). Basically, they do not make an intermediate switch like ours but uses a system back at the CCU on the...

www.electriciansforums.net

You can use the teleinterupteurs instead of two-way if you want. Then it's easy to add further switches in the future.