Museum of Plugs and Sockets logo, small CEE 7/3 - 7/4 standard
Schuko type plugs and sockets
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CEE 7/3 refers to sockets, CEE 7/4 to plugs. Plugs are characterized by earth clips, rather than earth pin. The standard, often indicated as 'Schuko' is adopted by a large number of continental European countries. See map of Europe for details.

Type F profile Related galleries:
uncommon types
classic types
alternative types

 

Schuko socket

Schuko male plug

Schuko female plug

Type E/F hybrid plug


1 CEE 7/3 (Schuko) type socket with two slots (line and neutral; not polarized) and two earth clips. All types of outlets are recessed (see nos. 1 and 3), to ensure that contact between fingers and pins is not possible, even if plugs are not fully inserted. Pairs of notches (arrows) and corresponding guides at the Schuko plugs (see no. 2) give extra stability and guidance.
Brand name: Merten (part of Schneider Electric GmbH, Germany).
2 CEE 7/4 (Schuko) plug, rated at 16A, 250V. Line and neutral pins have a diameter of 4.8 mm. Green arrows indicate the guides (see socket no. 1 for corresponding notches). Brand name: Heinrich Kopp GmbH, Germany.
3 Female Schuko plug, rated at 10-16A, 250V. The dual rating indicates that plugs can be used in domestic 10A circuits as well as 16A circuits.
4 Plug with an additional slot accepting the earth pin of French sockets (green arrow). Therefore, this plug fits into both Schuko and French sockets. A separate page gives more examples and additional information about CEE 7/7 and other hybrid plugs.
Brand name: ABL-SURSUM, Germany. ABL stands for Albert Büttner Lauf (Lauf is a town close to Nürnberg, Germany).

 

About Schuko

Schuko is an abbreviation of the German word "Schutzkontakt", which means protective contact. Two important safety features are:
(i) plugs have earth clips that make contact first, and (ii) sockets are recessed; pins under tension can't be touched.

The original design of a safe, earthed plug and socket was an idea of Albert Büttner (Bayerische Elektrozubehör in Lauf). Patent was granted in 1926. Plugs had earth clips rather than a (third) earth pin. Further developments resulted in a version that was patented in 1930 by the Siemens-Schuckerwerke in Berlin. The patent describes the plug and socket that is still in use and became known as Schuko.
Schuko is a registered trademark of the SCHUKO-Warenzeichenverband e.V., Bad Dürkheim, Germany.

A separate page gives the full story of the origin of Schuko.

The Schuko system has proved to be very solid, but being unpolarized - line and neutral are reversible - is often regarded as a disadvantage. Note that polarized Schuko plugs exist, but they seldom used. An example is shown on the page about uncommon plugs.

Schuko plugs are indicated by a CEE number, given by the International Electrotechnical Commission for Electrical Equipment.
Relevant CEE numbers are: CEE 7/3 = Schuko 16A-250V socket (see no. 1), CEE 7/4 = Schuko plug 250V-16A, (see no. 2), CEE 7/7 = Schuko-French hybrid plug (see no. 4).

Essentially the same Schuko devices are used in Russia and eastern European countries, except Poland, Czech Republic and Slovakia.
Plugs may have several country specific marks. Read about their origin and significance on the certification marks page.

 

Schuko plug with additional grip

Schuko plug with switch

Schuko plug with rotatable switch

Schuko switched adaper and multi-outlet

Schuko multi-plug

Schuko multi-plug with Schuko and Europlug outlets

5 Schuko plug with large grip to facilitate plug removal. Unknown brand, probably Chinese.
6 Schuko plug with tumble switch. See page on uncommon Schuko variants for details. Brand name: Merten (Schneider Electric). 
7
Schuko plug with a rotating ring to switch contact on and off. Unknown brand, possibly made in China.
8
Extension cord with triple outlet and plug with switch adapter and indicator light. Note that slots are protected by shutters (red).
Safety shutters are not (yet?) compulsary in the Netherlands
.
9 Schuko three-way multi-plug.
10 Multi-plug for Euro and Schuko plugs. There are many variants on this theme.

EVOline Schuko plug Removal of EVOline Schuko plug
11, 12

The EVOline® Schuko plug is a striking design by Schulte Elektrotechnik GmbH, Germany.
The plug is elegantly flat. It protrudes only 5 mm when fully inserted in a  Schuko socket.
The pin housing has a movable joint. This construction allows a simple removal of the plug; just use the flat plate as a lever (see image no. 13).
The plug has the usual Schuko rating of 16A, 250V.


Schulte Elektrotechnik

DUOversal Schuko triple outlet
13

DUOversal '3=6' extension cord with a triple outlet. Each of the outlets can be used for either a Schuko plug, or two Europlugs. The center outlet shows the ingenious design by Heinrich Kopp GmbH, Germany. The extension cord is rated at 16A, 250V. There is also a version with six outlets ('6=12').
Note that the "3=6" principle is not allowed in the Netherlands. The reason for this is that Dutch regulations stipulate that an outlet may only have two contacts (one for L-pin, the other for N-pin).   {KB}

 

Schuko plugs and non-earthed sockets

Non-earthed socket

Non-earthed socket with Schuko plug

Outlet of non-earthed extension cord

Multi-outlet only suitable for CEE 7/16 and 7/17 plugs





14, 15 Non-earthed socket (no. 14) that accepts Schuko plugs (no. 15). This practice causes a potentially unsafe situation, because the Schuko earth clips do not make contact with an earthing system. Preferably non-earthed sockets of this type should have a provision that makes them inaccessible for Schuko plugs; see nos. 16 and 17 for examples.
16 A provision against Schuko plugs is occasionally found on outlets of non-earthed extension cords. The green arrows point to fins at positions that correspond to earth clips of a Schuko plug. These fins make it impossible to insert a Schuko plug. A simple but effective safety measure that forces people to use a three-wire extension cord with male and female Schuko plugs.
Sockets with fins exist - see no. 17 - but are seldom seen.
17 Multi-outlet of an extension cord that is only suitable for not earthed CEE 7/16 and CEE 7/17 plugs. Not earthed CEE 7/2 (model with round base) and earthed CEE 7/4 (Schuko) and CEE 7/6 (French) plugs do not fit in the outlets. Note that one of the fins has been broken off (deliberately?). The outlet has been made in France by BRUN. Details about the company are unknown. This rare multi-outlet has been found in 2014 in Marseille by Wojciech Maciak.

 

Bakelite Schuko socket
Polarized Schuko plug, small
Terco socket
Classics
Classic Schuko models are essentially identical to modern types, but used materials and details are different.

Uncommon Schuko variants
Schuko plug and socket variants that deviate(d) from commonly used standard CEE 7/3 - 7/4 material.

Alternatives to Schuko
Alternative plugs and sockets, fully different to Schuko, exist for applications in which polarization is essential.

 


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