Wiring

To do what?

Why is 'France' significant?

Because that is were I will be installing the switch for my daughter.

Wiring a daughter to the mains via a 3- or 4-way switch is not to be recommended, even if her behaviour makes it tempting.

Thanks

logical

Here is a diagram.

The wiring of a light fitting between two switches, as shown in one of the diagrams on that site, would not be permitted in the UK. The original poster needs to bear that in mind.

I agree . . . It's not so bad if lamps are incandescent, but if they're fluorescent, then you get a reversal of current in an inductor => BAD

The current always reverses in an inductor at the rate of alternation of the current. That's not the reason.

Given the circuit shown there's a 50% chance of a lamp-holder still having a live wire going to it when there's no current flowing, placing the individual that changes a failed lamp at increased risk of shock. Switches in the neutral line are bad practice. What might be acceptable on 120VAC becomes hazardous on 220VAC and above.

We're talking about two slightly different things . . .

The illegitimate way to wire a 3-way switch is to put the lamp in the common legs of the two switches. Inductive loads are much worse than non-inductive loads, 'cause the voltage instantly reverses.

I agree with you about breaking the neutral, but the bottom two diagrams are the same, and neutral is not broken -- it's always connected to the lamps.

<Inductive loads are much worse than non-inductive loads, 'cause the voltage instantly reverses.> On a 50Hz supply the voltage applied to a single-phase load reverses 100 times per second. On a 60Hz supply it is 120 times per second. It doesn't matter whether the load is inductive, capacitive, resistive or some combination; it's not relevant.

<neutral is not broken -- it's always connected to the lamps>

What about when both switches are connected to the live wire and the lamp is off? At this time, anyone changing the lamp and touching either of the two contacts is potentially (aaaargh!) connected to the live wire, risking an electric shock! This is why the arrangement shown in that sketch is not permitted in the UK for connection to the mains.

Thanks I have this diagram;but the wiring,switches and voltage they use in France are different than what we use in the USA

I have to agree with JRaef in post #9. I have installed switches etc. in US, Europe, and South America. The components may look different, and of course higher voltage allows smaller wire to carry the same power as larger wire at lower voltage, but the function is the same. A three way switch (also known as single-pole double-throw) will always move some conductor to connect point C (common) to either point A or point B. And so on...

As indicated by at least two others, the circuit chosen should maximize safety of the ignorant (only non-energized wires leading to the socket of a lamp in the off position, if possible).

Sorry, but AC power does not know borders or languages, it all works the same. The switches may look different, but they would operate the same way; the concepts are fundamentally identical no matter where the circuit is. You may need to apply some human brain power in a process called "adaptive interpretation" in order to make it work. If you (or your daughter) cannot figure this out, you have NO BUSINESS messing with electricity and need to hire a professional electrician. They will not need to ask for help.

In the US many newly purchased switches come with a wiring diagram right in the box (small instruction sheet) or on the box, can't speak for products purchased in France though.

ouvrez la boîte. lisez les instructions et suivez-les.

Le pouvoir passe par les changements avant le fait d'atteindre la charge dans n'importe quel pays.

Here's a sketch of two 3 Way and one 4 way switch circuit.

This arrangement is the recommended way for wiring a single lamp, or a cluster that operates as one, from multiple switches. Changing any switch turns the lamp from on to off or vice-versa. The neutral is carried through to the lamp and the arrangement ensures that, when the lamp is off, no live connection is made to the lamp. This is the correct way for mains voltages so as to ensure safety.