Electrical sockets standard 7. List of plug connector standards

We purchase a lot of electrical household appliances of varying power, made in EU countries, whose power cords end with European-type electrical plugs. It is known that they differ not only in the diameter of the metal part from our domestic ones, but also in their shape, greater potential power and the presence of one or two grounding contacts. But we must not forget about the so-called “Soviet” type, which is still widely used in Russia and the CIS countries along with electrical appliances of past times; therefore, we will begin a brief review of European-type electrical plugs with them.

One of the most common plug designs in the USSR, designed for 220V, 6A

This type, called Soviet C1/B, is still produced in our homeland and in terms of its qualities it can be equated to the European type CEE 7/16 Europlug. Electrical plugs of this type are designed for a current of 6 A and 10 A at a voltage of 220 - 250 V and a frequency of 50 Hz. They do not have grounding terminals, but they have one advantage, which is that their design is collapsible, which means that if the cable is damaged, you can replace it, leaving the socket the same and without spending money on a new one. The diameter of the pins in the Soviet plug is 4 mm.

The next type of electrical plug, which also has pins with a diameter of 4 mm and which is widespread in European countries except England, Ireland and Malta, belongs to the CEE 7/16 Europlug class. It is used when operating low-power household electrical appliances, without grounding contacts and is designed for a current of up to 2.5 A at a voltage of 1100 - 220 V. Compatible with classes C, C1, E, F.

Type C6 (in Europe CEE 7/17) we have a “Euro plug”, with round pins (knives) with a diameter of 4.8 mm

But the French type of electrical plug has metal pins with a diameter of 4.8 mm and one grounding contact. Widely used in France, Poland and Belgium. Used for medium-power appliances such as vacuum cleaners, air conditioners, water heaters, etc. This type of plug can withstand current up to 16 A at a voltage of 220 - 250 V. Compatible with sockets of type C, E, F, but with Soviet type C1 /B are incompatible and can only be used with an adapter.

For electrical appliances of medium and high power consumption, the European German type of plugs “Schuko” CEE 7/4 is used, which is widespread in Germany, Sweden, Norway and Holland.

CEE 7/4 Schuko plug and Schuko socket

Designed for a current of up to 16 A, in some versions up to 25 A at a voltage of 220 - 250 V, has a pin diameter of 4.8 mm, one grounding pin and is compatible with sockets C and F. According to its characteristics, “Schuko” CEE 7/4 Suitable for French type E CEE 7/5 plugs.

There is also a hybrid type of E/F electrical plugs - CTT 7|7, which combines German and French quality. Very common in European Union countries when using medium and high power consumption devices. They have a grounding contact and are suitable for sockets of type C, E and F with a metal pin diameter of 4.8 mm.

Double Schuko socket with inserted plug

« Schuko" (pronounced "Shuko") is the colloquial name for the system of AC power plugs and sockets officially defined in the CEE 7/4 standard or known informally as "Type F".

"Schuko" is an abbreviation for the German term Schutzkontakt(Schutzkontakt, literally: "protective contact"), which simply indicates that the plug and socket are equipped with protective grounding contacts (in the form of staples, not pins). Schuko connectors are typically used in 230 V, 50 Hz circuits for currents up to 16 A.

The Schuko system originated in Germany and originates from patent DE 370538, issued in 1926 to Albert Büttner, a Bavarian manufacturer of electrical installation products. The system is used in more than 40 countries, including most of continental Europe. .

Device

CEE 7/4 Schuko plug and Schuko socket

The Schuko plug has two 4.8 mm diameter round pins (19 mm long, 19 mm center to center) for phase and neutral, and two flat terminal clips at the top and bottom of the plug for safety grounding. Schuko sockets form a recess into which the plug is inserted. Schuko plugs and sockets are non-polarized, phase and neutral connections are not controlled. Like most types of European sockets, Schuko sockets can accept Europlugs.

When inserted into a socket, the Schuko plug closes the cavity of the socket 1 and first establishes a protective ground connection through the grounding clamps 2 before the phase and neutral pins 3 come into contact. This prevents touching the pins of a plug inserted into the socket, which means that insulating sleeves on the pins are not required. Guide grooves 4 are needed for stability; they allow the use of large and heavy plugs (for example, with a built-in transformer or timer).

Safety

• Protective grounding is not connected. Non-current-carrying parts of the device are not protected from breakdown and static electricity;
• the plug enters with force. This force can damage the outlet, and it will also be difficult to turn off the device if necessary. Often, when you try to unplug a Schuko plug from the socket, the socket falls out of the socket, exposing live parts;
• since the pins have a larger diameter, later there may be problems with poor contact when connecting other devices to the same socket;
• The Schuko plug is designed for a current of 15A. A socket that is not designed to accept Schuko plugs, especially if the diameter of the holes in the socket is less than 5.5 mm, may not be designed to handle the current consumed by the device when it is turned on;
• If the socket is not recessed, like Schuko, there is a possibility of touching the live pins if the plug is not inserted completely.

Unfortunately, in Russian houses The old building does not have a grounding loop. Therefore, often newly installed Schuko sockets are either not grounded at all, or the grounding contact is connected to the neutral wire in the socket, or the devices are grounded to heating pipes, water supply, or to the fittings of the house. All this is a violation of safety regulations. GOST 7396 does not prohibit the use of sockets with holes with a diameter of 5.5 mm, rated for 15A, but without a grounding contact. Similar sockets are made in many countries. The use of such sockets is also a violation of the safety principles laid down in the Schuko standard.

Compatibility and Distribution

CEE 7/7 - hybrid of French plug and Schuko

Most modern Schuko molded and dismountable plugs are hybrid versions ("CEE 7/7"), with a hole that accepts the ground pin of French sockets. CEE 7/7 has become a de facto standard throughout the European Union and in many other countries following CENELEC standards.

Exceptions in the European Union that do not use CEE 7/7 are:

• Denmark (the current standard, 107-2-D1, accepts CEE 7/7 plugs, but without a ground connection. The French standard came into force on July 1, 2008, but it has not spread much.),
• Ireland (BS 1363 / IS 401),
• Great Britain, including Gibraltar (BS 1363).

In countries former USSR Either sockets are used that accept type plugs designed for Ø4 mm pins, or Schuko sockets, although there are sockets without grounding that have Ø5.5 mm holes into which a Schuko plug can be inserted.

Bipasso socket (number 1) and Italian adapted socket schuko(number 2 in the photo) in a modern product.

Italian socket of the VIMAR universale brand, capable of accepting plugs of types A, C, E, F, E/F hybrids and both Italian types of L plugs.

In Italy the standard (CEI 23-16/VII) dominates, however, Schuko is approved and widely used. The devices are sold either with an Italian plug or with a Schuko. Some outlets accept both types of plugs, but most only accept one of them. Schuko plugs are most often used in appliances that consume high current, such as washing machines. They are quite widespread in South Tyrol, with its cultural, economic and tourist ties to Austria.

Countries that have abandoned the Schuko standard

Although in Belgium and France Schuko has never been a de facto standard, it can sometimes be found in older houses in the eastern region of Belgium and Alsace. All new installations comply with national standards.

In some places in the Republic of Ireland Schuko was installed until the 1960s. For security reasons, to align with the UK (with which Ireland has a long-term free travel agreement) and to avoid the presence of different types socket outlets in Northern Ireland and the Republic of Ireland, Ireland has adopted BS 1363 (in Ireland IS401 (plug) and IS411 (socket)). This standard was adopted when the UK was phasing out BS546 plugs and sockets (which were also sometimes used in Ireland). The adoption of BS 1363 has made it impossible to connect Schuko earthed plugs to ungrounded socket-outlets, or to BS546 socket-outlets without an earthed connection. In Great Britain there were similar problems, and BS 1363 was specifically designed to be incompatible with any existing system, thereby forcing you to comply with grounding standards and use fuses. It should also be noted that in the 1960s, compatibility with other countries was not an issue, since there were few compact electrical appliances that people took with them when traveling.

However, in the Republic of Ireland, wiring practices remain more similar to those found in continental Europe, particularly Germany. Sockets (which, unlike British ones, often do not have switches) are usually powered from radial lines rated at 16A or 20A, unlike British ring wiring, and are necessarily protected by an RCD for a leakage current of 30mA. Fuses and other components comply more with German DIN standards than British standards.

Schuko has been completely phased out in Ireland; it is not found in enterprises; it is very rarely found in private homes. However, some hotels provide European visitors with Schuko sockets along with BS 1363 sockets for convenience.

Criticism

Schuko sockets have been criticized for not being fused, being non-polarized in design (although the need for polarization has also been questioned), the considerable effort required to connect and disconnect the plug, which is a problem for some people, and their large dimensions. The IEC 60906-1 standard was developed as a replacement for the CEE 7/4 standard, but is not widely used.