French power sockets have a protruding ground. Why did they make this decision?

I can't see any major benefits from it, it saves some pennies on each power cord, but it exposes the ground connection to people nearby, which can be dangerous as in real life grounds are not perfect, they can have a live voltage and are a risk of electric shock if there's lightning nearby.

Once someone told me they are safer because the ground connects first, but this is also nonsense as the order of connection depends on the size of the plugs alone and not where they are.

In case you don't know what I am talking about:

French power outlet

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    \$\begingroup\$ It does ensure the ground connects before anything else does. "Once someone told me they are safer because the ground connects first, but this is also nonsense as the order of connection depends on the size of the plugs alone and not where they are." I don't understand what you are trying to say here. I don't see why size of plugs or where they are has anything to do with anything. \$\endgroup\$ – DKNguyen Feb 14 at 5:43
  • \$\begingroup\$ How? You don't need to put the plug on the outlet in order to ensue this, just make the ground pin longer on the power cord. \$\endgroup\$ – mFeinstein Feb 14 at 5:44
  • \$\begingroup\$ Perhaps they could not make the ground pin any longer due to risk of mechanical damage, but they could not make the hot and neutral pins any shorter because then they would be hazardously close to the front of the socket \$\endgroup\$ – DKNguyen Feb 14 at 5:46
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    \$\begingroup\$ It is a design that works, the UK has an earth pin that is longer than the other two pins and that also works. Each country thinks its own design is best, or the design of the country they are asdociated with... \$\endgroup\$ – Solar Mike Feb 14 at 5:47
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    \$\begingroup\$ Also, ground connections are already exposed just from the screws holding outlet faces to the wall (well, if France is anything like North America). So if they are mis-wired, it's not like concealing the ground prong is protecting anyone. \$\endgroup\$ – DKNguyen Feb 14 at 5:48

I'm not 100% sure, but I believe that the reason for the unusual earthing arrangements on french and german plugs is backwards compatibility with existing installations.

Appliances can be categorised into 3 categories.

  • Class 0: no earth connection, not "single fault safe" (now banned in most first-world countries)
  • Class 1: "single fault safe" only if an earth connection is present.
  • Class 2: no earth connection, "single fault safe"

If your existing installed base of installations has no earth provision and your existing base of appliances is class 0 then it can be argued that it is sensible to let people plug class 1 appliances into their existing unearthed sockets. They aren't any less safe than the old class 0 appliances were.

There is also an argument to be made that having some appliances earthed while there are class 0 appliances in use makes things less safe than having no earthing at all.

Adding a conventional earth pin disallows plugging new appliances into existing installations, and does nothing to prevent old class 0 appliances from being brought into new earthed installations.

The design of the German and French plugs on the other hand allows new appliances to be used in existing installations in a way that is no less safe than before, while keeping old class 0 appliances out of new installations.


Once someone told me they are safer because the ground connects first, but this is also nonsense as the order of connection depends on the size of the plugs alone and not where they are

You are right. The ground pin could be on the cord itself. But it is how it is. But this is a generic argument, looking at may available type sockets and plugs used worldwide (Type A to Type N).

Until there is one universal plug and socket adaption say by the year 2200 (Like phone charger pin types reduced to two now, majorly from many. ), the variants are going to stay.


Plug Type E

Used in: France, Belgium, Slovakia and Tunisia among others (see complete list of countries on the right)

The Type E electrical plug has two 4.8 mm round pins spaced 19 mm apart and a hole for the socket's male earthing pin. The Type E plug has a rounded shape and the Type E socket has a round recess. Type E plugs are rated 16 amps.

Note: The CEE 7/7 plug was developed to work with Type E and Type F sockets with a female contact (to accept the earthing pin of the Type E socket) and has earthing clips on both sides (to work with Type F sockets).


  • \$\begingroup\$ Do you think the politicians could get together and agree a “common” plug ? :) \$\endgroup\$ – Solar Mike Feb 14 at 8:01
  • \$\begingroup\$ Yes..by 2200 for sure \$\endgroup\$ – User323693 Feb 14 at 8:35
  • \$\begingroup\$ Won’t happen, probably because some or all the countries won’t exist by then... \$\endgroup\$ – Solar Mike Feb 14 at 8:40
  • \$\begingroup\$ @SolarMike that's the catch.. probably at that point in time it will easy to settle to one or none :P \$\endgroup\$ – User323693 Feb 14 at 8:42
  • \$\begingroup\$ Just saying, France also invented metric time...compatibility hasn't always been their primary consideration. mentalfloss.com/article/32127/… \$\endgroup\$ – Cristobol Polychronopolis Feb 14 at 14:07

Without the original argumentation how the design was presented to be the one and only right version we can only guess.

My guess: It's difficult to modify existing non-grounded non-double-insulated device plugs to fit. Grounding at the edges of the plug need only a little material removal with a saw or knife or by melting. This type of grounding needs a hole which requires more complex tools and there can be metal inside the plug in front of the drill.


This design forces the user to only plug compatible equipment in that socket. That is, if you get a German-only plug (where ground contacts are elsewhere), you simply won't be able to insert it in the French socket, as there will be no hole to receive the ground pin. If the plug fits, you can be quite certain that the appliance is correctly grounded. Indeed, this doesn't apply to flat plugs which have no ground pin, but appliances having such plugs don't require grounding in the first place.

In the opposite case (French-only plug, German socket) the plug will mechanically fit, but the ground will not be connected, giving a misleading impression of safety.

When the ground contact goes live, no plug design will make it safe: no matter how concealed the ground pin is, you will get a shock the moment you try to operate the equipment you have plugged in.

BTW, I don't see how this design "saves some pennies on each power cord", because you still need to make a female receptacle for the ground pin, which I suspect cost more than a third pin would have.

  • \$\begingroup\$ "in the opposite case (French-only plug, German socket) the plug will mechanically fit" no it won't. The german plug (and the hybrid german/french plug) has notches that the french plug does not and the socket cavity is shaped to require these notches. \$\endgroup\$ – Peter Green Feb 15 at 18:09
  • \$\begingroup\$ This logic applies to almost all sockets, you can't fit an American power cord on a British outlet for example, and neither have a ground protruding. \$\endgroup\$ – mFeinstein Feb 15 at 23:07
  • \$\begingroup\$ What I meant about saving money is that it's cheaper to make a metallic ring to connect the ground plug, than a plug, as it takes a lot more metal. \$\endgroup\$ – mFeinstein Feb 15 at 23:08

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