What does an American electrical plug look like? Types, design and markings of modern household electrical outlets

Most often, electrical appliances are supplied already with ready-made system connecting them to the network. However, there are situations when it is necessary to replace an element such as an electrical plug. Choose suitable option is very important, as well as connecting it correctly. In order to avoid unpleasant situations in the future, you should study the technology for repairing equipment.

Types of electrical plugs

There are only three types of electrical plugs. These are collapsible and non-dismountable (cast) types of equipment.

Each of them performs the same function. An electrical plug of any type serves as a connection between the network and the current conductor.

Molded forks have gained great popularity in the world of modern household appliances. They are reliable, aesthetic and also comfortable. The wire is attached to the pins by spot welding. The system in this case resembles a single wire. In this case there is no contact. This method of fastening ensures that there is no oxidation or weakening at the junction of the wire with the pins of the plug.

The cause of failure of a cast plug is a fracture of the conductor at the base. Typically, such devices are not repaired.

A removable plug will help bring the device back to life. The electrical cord and plug are connected very tightly. The better the contact, the better the equipment works.

World fork markings

Depending on the state that produces the presented equipment, there are 13 types of gifts and plugs for them. They are marked with Latin letters.

Types A and B of electrical plugs are assigned to American plugs. Type A does not have a ground connection, and Type B already contains a place for its connection. Their pins are flat.

Type C belongs to European plugs with round pins without grounding. English sockets are marked D. The pins are round, two thin and one thick.

French electrical plugs with a grounding point have two round prongs. The third is in the socket.

An F type grounding plug is similar to a C. It only has two grounding plates.

TO English plugs include types M and G. Other European varieties include sockets J, K, L. Australian plugs for electrical cords are marked with the letter I, and Israeli ones - H.

Adapters are used to connect the plug to incompatible sockets.

Electric plugs in our country

In our country there are 4 types of trailed and cast forks.

Type C is a non-separable plug. They most often come with household appliances and are connected to a cord.

Type C5 has round pins with a diameter of 4 mm, without ground contacts. The power of the equipment connected to such a plug does not exceed 1.3 kW (6 A).

Type C6 belongs to equipment such as an electrical plug, which may not have a grounding connection. In some versions they have a grounding pin. The diameter of the pins is 4.8 mm. The plug is designed for power up to 2 kW (10 A).

Type C1-b includes collapsible varieties designed for a power of 1.3 kW (6 A).

Which fork is better?

There is an opinion among professional electricians that a cast plug is still more reliable. This applies to quality products from well-known manufacturers.

The connection of the wire to the pins occurs in production by soldering or, in very rare cases, crimping. Subsequent hermetic casting of the housing reliably protects the connection point and also prevents oxidation processes in this section.

The only weak point of such a product is the connection between the conductor and the plug. If a break occurs, it is better not to try to disassemble the cast version of the product. If you decide to repair the device, you should connect a detachable plug to the wire.

Rules for connecting plug C1-b

Different types of electrical plugs will require certain installation rules to be followed for each one.

For dismountable plugs C1-b, ensure good contact of the wire with the pins. The ends of the conductors should be tinned.

The insulation from the cable is removed by 20-25 mm without touching the cores. Rings should be formed around the crimp screws of the fork. The remaining overlap is wound around the stripped base.

The finished ring is removed and carefully tinned so as not to put pressure on the insulation. Then they are put back on the screws and clamped until they stop. You need to be careful not to break the thread.

The pins with wires are inserted into the mounting recesses. The outgoing wire is pressed with an insulating strip without damaging the outer sheath of the cable. Next, the plug halves are tightened with a bolt and nut.

Connecting the wire to plug C5 and C6

Here the process of connecting the wire is even simpler. The electric plug of type C5 and C6 already includes special pads. There is no need to form rings. Wire with a cross section of 2.5 mm square. envy up to 10 mm, and from 1.5 mm sq. - up to 20 mm. This is due to the connection technology.

Thin wires will need to be folded in half before fastening. The core is twisted and inserted into the terminal.

From time to time it is better to tighten the pads in order to ensure good quality contact. It is quite good in such devices.

If the electrical network does not provide grounding, you should not connect an extra contact anywhere. The third conductor is left unstripped as a reserve. It can be useful if one of the wires breaks.

If you install a plug with a high power rating on an electrical appliance, this will increase its safety margin. However, if you install a fork with a smaller load-bearing power on your equipment, you should expect it to overheat, fail, and create an emergency situation. Be sure to pay attention to the marking of the plug and the power of the household appliance.

Having familiarized yourself with the types of electrical circuit element such as an electrical plug, you can choose the right option to replace the old plug. There are several types of such devices. Each is selected in accordance with the required load of the household appliance to which the wire and plug are connected. By making the connection in accordance with all the rules, you can have no doubt about the durability and safety of operation of the electrical plug.

List of plug standards

List of plug standards

The two most common standards in the world are voltage and frequency. One of them is the American standard 110-127 Volt 60 Hertz, together with plugs A and B. The other standard is the European standard, 220-240 Volt 50 Hertz, plugs types C - M.

Most countries have adopted one of these two standards, although transitional or unique standards are sometimes found. On the map we can see in which countries certain standards are used.

Voltage/Frequency.

Types of forks.

Types currently in use

Electrical plugs and sockets vary from country to country in shape, size, maximum current rating, and other features. The type used in each country is fixed by law by the adoption of national standards. In this article, each type is designated by a letter from a US government publication.

Type A

Non-polarized Type A plug

NEMA 1-15 (North American 15 A/125 V, ungrounded), according to GOST 7396.1-89 - type A 1-15

Unusual American 5-socket Type A block, circa 1928

This type of plug and receptacle, with two flat parallel non-coplanar (not in the plane of the plug body) blades and slots, is used in most North American countries and on the east coast of South America, with devices that do not require grounding, such as lamps and small devices with double isolation. This type accepted by 38 countries outside North America and standardized in the United States by the National Electrical Manufacturers Association (NEMA) NEMA 1-15 receptacles have been banned in new buildings in the United States and Canada since 1962, but remain in many older homes and still sold for repair. Type A plugs are still very common because they are compatible with Type B sockets.

Originally, the pins of the plug and the slot of the socket were the same height, and the plug could be inserted into the socket in any orientation. Modern plugs and sockets are polarized with a wider neutral contact so that the plug can only be inserted the right way. Polarized Type A plugs will not fit into non-polarized Type A receptacles because both slots in the receptacle are equally narrow. However, both non-polarized and polarized Type A plugs fit into a polarized Type A receptacle and a Type B receptacle. Some devices for which the location of the live and neutral wires is not important, such as sealed power supplies, are still manufactured with non-polarized Type A plugs (both blades are narrow ).

Japanese socket with grounding plug, for washing machine.

JIS C 8303, Class II (Japanese 15 A/100 V, ungrounded)

The Japanese plug and socket are identical to NEMA 1-15 type. However, Japan has stricter fork body sizing requirements, different labeling requirements, and requires mandatory testing and approval by the Ministry of International Trade and Industry (MITI) or JIS.

Many Japanese sockets and extension cords are non-polarized—the slots in the sockets are the same size—and only accept non-polarized plugs. Japanese plugs will generally fit most North American outlets without issue, but polarized North American plugs may require an adapter or replacement to fit into older Japanese outlets. However, the mains voltage in Japan is 100 V, and the frequency in the east is 50 Hz, not 60 Hz, so North American devices can be connected to the Japanese network, but correct work not guaranteed.

Type B

A type B fork has, in addition to parallel flat blades, a round or letter-shaped blade U ground contact ( American standard NEMA 5-15/Canadian CSA 22.2, _ 42). It is rated for a current of 15 Amps and a voltage of 125 Volts. The grounding contact is longer than the phase and neutral contacts, which means that the grounding connection is guaranteed before the power is turned on. Sometimes both power pins in Type B plugs are narrow because the ground pin prevents the plug from being plugged in incorrectly, but the slots in the socket are different sizes to allow Type A plugs to be plugged in correctly. If the ground pin is at the bottom, the phase will be on the right.

The 5-15 socket is the standard throughout North America (Canada, USA and Mexico). True, Mexico also uses Japanese-style sockets. The 5-15 socket is also used in central America, the Caribbean, northern South America (Colombia, Ecuador, Venezuela and parts of Brazil), Japan, Taiwan and Saudi Arabia.

In some parts of the US, new buildings are now required to install electrical outlets with protective curtains to prevent foreign objects from being inserted into them.

A 5-20R receptacle with a neutral T-slot installed with the ground pin facing up.

In theaters this connector is sometimes called PBG(Parallel Blade with Ground, parallel knives with the ground), Edison or Hubbell, by the name of the main manufacturer.

NEMA 5-20 (North American 20 A/125 V, grounded) according to GOST 7396.1-89 - type A 5-20

In new residential areas, since about 1992, 20-amp T-slot receptacles accept both 15-amp parallel-blade plugs and 20-amp plugs.

JIS C 8303, Class I (Japanese 15 A/100 V, grounded)

Japan also uses a Type B plug, similar to the North American one. However, it is less common than its type A equivalent.

Type C

Plug and socket CEE 7/16

(Not to be confused with three-pin IEC connectors C13 and C14)

CEE 7/16 (Europlug (Europlug) 2.5 A/250 V, without grounding), according to GOST 7396.1-89 - type C5 option II

For more information on this topic, see: Europlug.

This two-pin plug is known in Europe as Europlug (Europlug, not to be confused with Schuko, which is called Europlug in Russia). The plug is not grounded and has two 4mm round prongs that usually meet slightly towards their free ends. It can be inserted into any socket that accepts 4mm diameter round pins spaced 19mm apart. It is described in CEE 7/16 and also defined in the Italian standard CEI 23-5 and the Russian standard GOST 7396.

The Europlug is equipped with class II devices throughout continental Europe (Austria, Belgium, Bulgaria, Bosnia and Herzegovina, Hungary, Germany, Greenland, Greece, Denmark, Iceland, Spain, Italy, Latvia, Lithuania, Macedonia, the Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Turkey, Ukraine, Finland, France, Croatia, Czech Republic, Switzerland, Sweden and Estonia). It is also used in the Middle East, most African countries, South America (Bolivia, Brazil, Peru, Uruguay and Chile), Asia (Bangladesh, Indonesia and Pakistan) as well as in the former Soviet republics and many developing countries. It is also used in many countries along with the BS 1363 plug, especially the former British colonies.

This plug is designed for a current of 2.5 A. Since it is non-polarized, it can be inserted into the socket in any position, so the phase and neutral are connected randomly.

The spacing and length of the pins allow it to be safely plugged into most sockets CEE 7/17, type E (French), type H (Israeli), CEE 7/4 (Schuko), CEE 7/7, type J (Swiss), type K ( Danish) and type L (Italian).

Fork CEE 7/17

CEE 7/17 (German-French 16 A/250 V, ungrounded), according to GOST 7396.1-89 - type C6

This plug also has two round prongs, but they are 4.8mm in diameter, like the E and F types. The plug has a round plastic or rubber base that prevents it from being plugged into the small Europlug sockets. The plug fits only into large round sockets for types E and F. The plug has both a hole for the grounding pin and contact strips for the side contacts. The plug is used in conjunction with class II devices designed for high operating current (vacuum cleaners, hair dryers), and in South Korea- with any household appliances that do not require grounding. It is also defined in the Italian standard CEI 23-5. Can be inserted into an Israeli H-type socket, although this is not recommended as they are designed for smaller diameter pins.

Hybrid E/F type

CEE 7/7 plug

CEE 7/7 (French-German 16 A/250 V, with grounding), according to GOST 7396.1-89 - type C4

To be compatible with types E and F, a CEE 7/7 plug has been developed. It is polarized when used with a type E socket, but in type F sockets the connection between the phase and neutral wires is not observed. The plug is rated for 16 A. It has grounding clamps on both sides for connection to a CEE 7/4 socket outlet and a female contact for the grounding pin of a Type E socket outlet. Appliances supplied to countries using the E or F standard are supplied with this type of plug.

Type G

Plug according to British standard 1363. This type is used not only in the UK, but also in Ireland, Sri Lanka, Bahrain, UAE, Qatar, Yemen, Oman, Cyprus, Malta, Gibraltar, Botswana, Ghana, Hong Kong, Macau (Macao) , Brunei, Malaysia, Singapore, Indonesia, Bangladesh, Kenya, Uganda, Nigeria, Mauritius, Iraq, Kuwait, Tanzania and Zimbabwe. BS 1363 is also the standard for some former British colonies in the Caribbean such as Belize, Dominica, Saint Lucia, Saint Vincent and the Grenadines and Grenada. It is also used in Saudi Arabia in 230V appliances, although 110V appliances with a NEMA connector are more common.

This plug, commonly known as a "13-amp plug", is a large plug with three rectangular prongs forming a triangle. The phase and neutral contacts are 18 mm long and spaced 22 mm apart. 9 mm of insulation at the base of the pins prevents accidental contact with exposed conductor when the plug is partially inserted. The ground pin is approximately 4 x 8 mm and approximately 23 mm long.

The plug has a built-in fuse. It is needed to protect the supply wire, as in the UK ring wiring is used, protected only by a central fuse, usually 32A. Any fuse can be inserted into the plug, but according to safety requirements it must be designed for the maximum current of the device being protected. The fuse is 1 inch (25.4 mm) long in accordance with British Standard BS 1362. Connections to sockets are made with the neutral wire on the left and the live wire on the right (looking at the front of the socket), so that a blown fuse in the plug breaks the live wire. The same convention is used for all UK sockets connected directly to the 'mains' wiring.

British Wiring Regulations (BS 7671) require socket outlets in homes to have a shutter on the live and neutral openings to prevent anything other than electrical plugs from being inserted. The shutters open when a longer ground pin is inserted. The curtains also prevent the use of plugs of other standards. Plugs for Class II devices that do not require grounding have a grounding pin that is often made of plastic and serves only to open the shutters and comply with the phase and neutral connection rules. It is generally possible to open the shutters with the blade of a screwdriver to insert a Type C plug (but not the BS 4573 British razor plug) or other types of plugs, but this is dangerous as these plugs do not have a safety lock and may jam in the socket.

BS 1363 plugs and sockets began appearing in 1946, and the BS 1363 standard was first published in 1947. By the end of the 1950s it had replaced more early type D BS 546 in new devices, and by the late 1960s Type D devices were converted to Type BS 1363. Socket outlets often have phase switches for convenience and safety.

Type H

Two Israeli plugs and one socket. On the left is the old standard fork, on the right is the modernization of 1989.

SI 32 (Israeli 16 A/250 V, with grounding)

This plug, defined in SI 32 (IS16A-R), is not found anywhere except Israel and is not compatible with other types of sockets. It has three flat pins arranged in the shape of the letter Y. The phase and neutral are spaced 19 mm apart. The H-type plug is designed for 16A current, but in practice, the thin flat pins can cause the plug to overheat when connecting high-power devices. In 1989 the standard was revised. Now three 4mm round pins are used, placed in the same way. Receptacles manufactured since 1989 accept both flat and round prongs to accommodate both types of plugs. This also allows you to connect type H sockets to type C plugs, which are used in Israel for ungrounded devices. Older sockets, circa 1970s production, have both flat and round holes for the phase and neutral to accept both Type C and H plugs. As of 2008, Type H sockets, which accept only older Type H plugs, very rare in Israel.

This plug is also used in areas controlled by the Palestinian National Authority in the West Bank and Gaza Strip.

Type I

Australian 3 pin double socket with switches

AS/NZS 3112 (Australasian type 10 A/240 V)

For more information on this topic see: AS 3112.

This type of plug, used in Australia, New Zealand, Fiji, Argentina and Papua New Guinea, has a grounding pin and two flat power contacts in an inverted V shape. The flat blades measure 6.5 mm × 1.6 mm and are mounted under an angle of 30° to the vertical with a nominal distance between them of 13.7 mm. Australian and New Zealand wall sockets almost always have switches for added safety, just like in England. An ungrounded version of this plug, with two angled blades but no grounding pin, is used with small devices, have double insulation, but wall power sockets always have three contacts, including ground.

There are several variants of the AS/NZS 3112 plug, including a version with a wider grounding pin, used by devices with current consumption up to 15 A; Receptacles that support this contact also support 10-amp plugs. There is a 20 Amp version, with all three pins oversized, as well as 25 and 32 Amp options, with the pins larger than the 20 Amp plug, forming an inverted "L" for 25A and a horizontal "U" for 32A . These outlets accept plugs rated at or below the maximum amperage rating, but not plugs rated at higher amperages. For example, a 10A plug will fit into all sockets, but a 20A plug will only fit into 20, 25, and 32A sockets).

The Australasian standard plug/socket system was originally called the C112 standard (originating in 1937 as a temporary solution, adopted as a formal standard in 1938), which was replaced by the AS 3112 standard in 1990. As of 2005, the last significant change is AS/NZS 3112:2004, which requires insulation on supply contacts. However, equipment and cables manufactured before 2003 are permitted.

Chinese sockets accepting plugs types A, C (top) and I (bottom, standard)

China Compulsory Certification Mark (CCC)

CPCS-CCC (Chinese 10 A/250 V), according to GOST 7396 .1-89 - type A10-20

Although Chinese sockets have 1mm longer pins, they can accept Australasian plugs. The standard for Chinese plugs and sockets is established by documents GB 2099.1-1996 and GB 1002-1996. As part of China's commitment to join the WTO, introduced new system CPCS (Compulsory Product Certification System) certification, and the corresponding Chinese plugs receive the CCC (China Compulsory Certification) mark. The plug has three contacts, grounding. Rated at 10A, 250V and used in Class 1 devices.

In China, sockets are installed the other way around, upside down, compared to Australasian ones.

China also uses US-Japanese Type A plugs and sockets for Class II devices. However, the voltage between the contacts of a Chinese socket is always 220V, regardless of the type of plug.

IRAM 2073 (Argentine 10A/250V)

The Argentinean plug has three contacts, grounding, and is designed for a current of 10A, voltage of 250V. The standard is defined by the Argentine Institute for Standardization and Certification (Instituto Argentino de Normalización y Certificación, IRAM) and is used with Class 1 devices in Argentina and Uruguay.

This fork is similar in appearance to Australasian and Chinese forks. The length of the contacts is the same as Chinese version. The most important difference from the Australasian plug is that the phase and neutral are supplied to it in reverse.

Type J

Type J plugs and sockets

SEV 1011 (Swiss type 10 A/250 V)

Switzerland has its own standard, described in document SEV 1011. (ASE1011/1959 SW10A-R) This plug is similar to the Euro plug type C (CEE 7/16), except that it has an offset ground pin and no pins. insulated sleeves so that plugs that are not fully inserted into non-recessed sockets pose a hazard electric shock. Sockets used in kitchens, bathrooms and other wet areas are recessed, but those in other places are not. Some plugs and adapters have tapered ends and can be used anywhere, while others only fit into non-recessed outlets. Swiss sockets accept Swiss plugs or Euro plugs (CEE 7/16). There is also an ungrounded two-pin version with the same shape, dimensions and live-to-neutral spacing as the SEV 1011, but with a flatter hexagonal shape. The plug fits round and hexagonal Swiss sockets and CEE 7/16 sockets. Designed for current up to 10 A.

A less common version has 3 square contacts and is rated at 16 A. Above 16 A, the equipment must either be connected to the mains in a permanent way, with suitable branch protection, or connected using a suitable industrial connector.

Type K

Danish 107-2-D1, standard DK 2-1a, with round power pins and semi-circular ground pin

Danish computer socket, with rotated flat pins and semi-circular ground pin (used mainly for professional equipment), standard DK 2-5a

Section 107-2-D1 (Danish 10 A/250 V, grounded)

This Danish standard plug is described in Danish Plug Equipment Section 107-2-D1 Standard sheet (SRAF1962/DB 16/87 DN10A-R). The plug is similar to the French Type E, except that it has a grounding pin instead of a grounding hole (it's the other way around in a socket). This makes the Danish socket more discreet than the French socket, which appears as a depression in the wall to protect the ground pin from damage and from touching the power pins.

The Danish socket also accepts Europlug type C CEE 7/16 or type E/F CEE 7/17 Schuko-French hybrid plug. Type F CEE 7/4 (Schuko), E/F CEE 7/7 (Schuko-French hybrid), and type E grounded French plug will also fit into this outlet, but should not be used for devices that require a grounding contact. Both plugs are rated at 10A.

The variant (standard DK 2-5a) of the Danish plug is intended only for interference-proof computer sockets. It fits into the corresponding computer socket and the normal K-type socket, but the normal K-type plugs are intentionally made to not fit into the dedicated computer socket. This plug is often used in companies, but very rarely at home.

There is also an option for medical equipment, with a rectangular left pin. It is often used in life support systems.

Traditionally, all Danish sockets were equipped with a switch to prevent touching live contacts when connecting/disconnecting the plug. Today, the use of sockets without switches is permitted, but such sockets must have a recess that protects a person from touching live contacts. However, usually the shape of the plug makes it very difficult to touch the contacts when connecting/disconnecting.

Since the early 1990s, grounded sockets have become mandatory in all new electrical installations in Denmark. Old sockets do not need to be grounded, but from 1 July 2008 all sockets, including old ones, must be protected by an RCD (HFI in Danish terminology).

Since 1 July 2008, type E (French, two-pin, earthing pin) wall sockets have been permitted in Denmark. This was done because equipment with K-type plugs was not sold to individuals and to break the monopoly of Lauritz Knudsen, the only company making K-type plugs and sockets.

Schuko type F sockets will not be permitted. The reason is that most plugs currently used in Denmark will get stuck in a Schuko socket. This can damage the socket. This may also cause poor contact, with the risk of overheating and fire. Broken F sockets can often be seen in German hotels frequented by Danes. Many international travel adapters are sold outside Denmark with plugs conforming to types C CEE 7/16 (Europlug) and E/F CEE 7/7 (Franco-Schuko hybrid) that can be used in Denmark.

Type L

Plug and socket 23-16/VII

A visual comparison of Italian type L plugs rated at 16 Amps (left) and 10 Amps (right).

Italian electrical installation with sockets of both types L (16 A on the left; 10 A on the right).

CEI 23-16/VII (Italian type 10 A/250 V and 16 A/250 V)

The Italian standard for earthed plug/socket outlets, CEI 23-16/VII, includes two models, 10 A and 16 A, differing in pin diameter and pin spacing (see details below). Both are symmetrical and allow you to connect the phase with the neutral in any way.

The double standard was adopted because in Italy, until the second half of the 20th century, electricity for lighting ( Luce= lighting) and for other purposes ( Forza= force, electromotive force; or Uso Promiscuo= general purpose) were sold at different tariffs, with different taxes, were considered separate counters, and were transferred by different wires, ending different sockets. Although both electric lines (and the corresponding tariffs) were combined in the summer of 1974, many homes remained double-wired and double-metered for many years. Thus, two sizes of plugs and sockets became the de facto standard, still in use today and standardized in document CEI 23-16/VII. Older products are often equipped with one of the standard sockets, either 10 A or 16 A, requiring the use of an adapter to connect the other size plug.

Ungrounded Euro plugs CEE 7/16 (type C) are also widely used; they are standardized in Italy as CEI 23-5 and are suitable for most devices with low current requirements and double insulation.

Devices with CEE 7/7 plugs are also often sold in Italy, however, not every socket can accept them, since the pins of CEE 7/7 plugs are thicker than Italian ones. Adapters are cheap and are often used to connect CEE 7/7 plugs to CEI 23-16/VII sockets, but the rated current requirement is often violated (16A instead of 10A), which can lead to an unsafe connection in some cases.

CEI 23-16/VII (Italian 10 A/250 V)

The 10-amp variety extends the CEE 7/16 by adding a center ground pin of the same size. Therefore, CEI 23-16-VII 10 Amp sockets can accept CEE 7/16 Europlugs. This type of plug is shown in the first picture.

CEI 23-16/VII (Italian 16 A/250 V)

The 16 amp looks like a larger version of the similarly shaped 10 amp. However, the pins are 5 mm thick, with a distance between them of 8 mm (the 10A version has a distance of 5.5 mm), and are 7 mm longer. The packaging of these plugs in Italy may claim that they are of the “Northern European” type. In the past they were also called per la forza motrice(For electromotive force) (about driving force forks, see above) or sometimes industriale(industrial), although the latter was never the correct definition, since enterprises used predominantly three-phase current and special connectors.

Two-size or multi-size sockets

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

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

Since it is a fact that the type of plugs found throughout Italy varies, in modern installations in Italy (and other countries where type L plugs are used) it is possible to find sockets that accept plugs of more than one standard. The simplest type has a central round hole and two holes at the bottom and top, made in the shape of a figure eight. This design allows the connection of both type L plugs (CEI 23-16/VII 10 A and 16 A) and Euro plugs type C CEE 7/16. The advantage of this type of socket is its small, compact front part. VIMAR claims that it patented sockets of this type already in 1975 with the release of their model Bpresa; however, soon other manufacturers began selling similar products, calling them in most cases by the generic term presa bipasso(two-standard socket), which is now very common.

The second fairly common type looks like an F receptacle, but with the addition of a central grounding hole. Sockets of this design can, in addition to Type C and 10 Amp L type plugs, accept CEE 7/7 (E/F type) plugs. Some of these receptacles may have figure-eight holes to accept 16-amp L-type plugs. The trade-off for versatility is twice the size of a normal L-type receptacle.

Other types may go even further in terms of compatibility. Manufacturer VIMAR produces a socket universale(universal) that accepts CEE 7/7 (Type E/F), Type C, 10A and 16A Type L, and US/Japanese Type A plugs.

Other countries

Outside Italy, type L CEI 23-16/VII (Italian 10A/250V) plugs can be found in Syria, Libya, Ethiopia, Chile, Argentina, Uruguay, various countries in North Africa, and occasionally in old buildings in Spain.

Type M

The term "Type M" is often used to describe the 15 amp version of the old British Type D used in South Africa and elsewhere.

In the USSR, two-pin sockets with non-spring solid ring contacts and a built-in fuse were initially used. These included forks with replaceable split round pins. Often on the back of the plug there were sockets for connecting another plug, which made it possible to connect plugs in a “stack” when there were not enough sockets. But later such plugs were abandoned, since the pins of such plugs often unscrewed and broke while remaining in the socket. Solid pin plugs required the pin to be held in place by spring pins in the socket, so older sockets cannot provide reliable contact between the plug and solid pins. However, low-power devices can be connected to such an outlet. Split plugs typically fit Type C pin diameters, but cannot fit into Type F sockets due to the shape of the housing.

Old spanish sockets

In old buildings in Spain you can find sockets with a special type of plug, which has two flat blades and a round pin between them. This species is vaguely similar to the American one.

The phase and neutral contacts have dimensions of 9 mm × 2 mm. The distance between them is 30 mm. All three contacts are 19mm long. The diameter of the grounding pin is 4.8 mm.

Despite the fact that the plug resembles the American one, the two flat contacts are much further apart from each other than in the American version.

There are no devices sold with these plugs. An adapter is needed.

British electrical clock connector

British three-pin clock connector and disassembled plug with 2A fuse.

Fused plugs and sockets of various non-interchangeable types can be found in older public buildings in Britain, where they were used to supply AC power to electric wall clocks. They are smaller than conventional sockets, usually designed to fit into BESA (British Engineering Standards Association) junction boxes, often almost flat. Older plugs had a fuse on both wires, newer ones only on the phase wire and had a ground pin. Most were provided with a retaining screw or bracket to prevent accidental disconnection. Gradually battery quartz watch almost completely replaced network ones, and with them similar connectors.

American "Type I"

American appliance manufacturers, Hubbell, Eagle, and perhaps others made sockets and plugs that were exactly Type I, similar to those used in Australia today. These sockets were installed in the United States in the 1930s for electrical appliances installed in a laundry room: washing machines and gas clothes dryers (to drive the motor). It was impossible to accept type A plugs, which is probably why they quickly fell out of use, being replaced by type B sockets.

Greek "type H"

Sockets, plugs and tees of the old Greek system

Before the widespread use of the schuko system, sockets similar to the H type with round pins were used in Greece, which were usually called τριπολικές (tripoliks).

Perpendicular rosette, USA

Perpendicular slotted double rosette

Perpendicular Soviet slot socket RP-2B for 10A 42V AC

Another outdated type of outlet from Bryant is 125V 15A and 250V 10A. A NEMA 5-20 125V 20A or 6-20 250V 20A plug with a missing ground pin will fit this outlet, but a NEMA 2-20 plug is too large for it.

The top slots, as seen in the picture, are connected to silver clamp screws on the top, and the bottom slots are connected to copper screws on the bottom.

In Australia, the same or similar T-shaped sockets are used for DC power, for example in Stand-alone Power Systems (SAPS) or on ships. In this application, the horizontal slot is placed at the top and is at positive potential. In the same way, sockets are used for temporary equipment in emergency vehicles. In Victoria it is customary that upper part The letter T is indicated by a minus sign and is therefore at negative potential. Outside Victoria, the vertical contact is designed to connect to the body/chassis. Top contact the letter T is positive on vehicles whose chassis is at negative potential. Also, the old transport is still running, with a positive potential on the chassis, that is, the polarity of the socket contacts can be any.

In the Soviet Union, and now in Russia, this socket was usually used to supply a reduced voltage for safety reasons, for example in schools, at gas stations, and in wet areas. The outlet is rated at 42V 10A AC. Such an unusual connection is necessary so that it is impossible to connect a low-voltage device to a 220V outlet.

US, combination double socket

The parallel-series receptacle accepts normal NEMA 1-15 parallel plugs as well as NEMA 2-15 series plugs. Both pairs of outlets are powered by the same source.

A more recent and fairly common version of this type is the T-slot rosette, in which serial and parallel slots were combined to produce T-shaped slots. This version also accepts normal NEMA 1-15 parallel plugs as well as NEMA 2-15 series plugs. By the way, a NEMA 5-20 (125V, 20A) or 6-20 (250V, 20A) plug without a grounding pin will also fit into this outlet. This type of socket has not been sold in stores since the 1960s.

Dorman & Smith (D&S), UK

D&S socket

The D&S standard was the earliest connector standard for ring wiring. The connectors were designed for a current of 13A. They were never popular in private homes, but were very often installed in prefabricated and municipal ones. They were also used by the BBC. D&S supplied sockets to local authorities at very low prices, with the intention of making money by selling plugs that typically cost 4 times the price of Type G plugs. It is not known exactly when D&S stopped producing plugs and sockets, but some local authorities continued to install them until the late 1950s years. D&S sockets were in use until the early 1980s, although the difficulty of obtaining plugs for them after 1970 forced residents to replace them with G-sockets. This generally contravened local council redevelopment orders. The D&S plug had a serious design flaw: the fuse, which also served as a phase pin, was connected to the plug body with a thread, and often unscrewed during operation, remaining in the socket.

Wylex, UK

Wylex plugs and sockets were manufactured by Wylex Electrical Supplies Ltd. as competitors to the G and D&S types. There were varieties of plugs designed for 5 and 13 amperes, with different widths of phase and neutral contacts and fuse ratings. The plug had a round ground prong in the center and two flat prongs on each side for phase and neutral, slightly above the middle of the center prong. Wall sockets were rated at 13A and accepted 5A and 13A plugs. Many 13A plugs have back side There was a socket into which you could only insert a 5A plug. Wylex sockets were installed in municipal and public housing, less often in the private sector. They were particularly popular in the Manchester area, although they were installed throughout England, mainly in schools, university housing and government laboratories. Wylex plugs and sockets continued to be produced after the final adoption of the G standard, and were widely used in banks and computer rooms throughout the 1960s and 1970s for uninterruptible power supplies or "clean" filtered networks. It is not known exactly when Wylex stopped producing plugs and sockets; however, plugs could be found on sale in the Manchester area until the mid-1980s.

Chuck adapters

Two Italian lamp sockets, with outlet. On the left is a 1930 example (porcelain and copper); right - ok. 1970 (black plastic).

The incandescent lamp socket plug fits into a bayonet or Edison screw socket. It allows you to connect electrical appliances to light bulb sockets. These plugs were widely used from the 1920s to the 1960s, when many homes had few or no wall outlets.

Often, lighting circuits are equipped with a 5A fuse or circuit breaker, which does not prevent the socket from overheating. Fuses were very rarely installed in the adapters themselves. In the UK and some other countries the use of such adapters is prohibited for fire safety reasons.

In Italy, plugs for Edison lamp sockets were used very widely, while the lighting network was separated from the general purpose network, and some places in the house (for example, basements) were not usually equipped with sockets.

Type A adapters can still be easily found in the Americas.

Rare types

NEMA 2-15 and 2-20

Ungrounded plugs with two flat parallel blades are a variant of the 1-15 plug, but are designed to supply 240 volts instead of 120. The 2-15 has coplanar power contacts (rotated 90° relative to the contacts in regular American plugs), and the voltage rating is current is 240V 15A, while 2-20 has two power contacts rotated 90° relative to each other (one vertical, the other horizontal) and a rating of 240V 20A. NEMA 2 plugs and sockets are very rare because they have been banned for decades in the US and Canada. They are potentially dangerous because they are not grounded, and in some cases the plugs may be inserted into outlets of a different voltage. Before the NEMA standard for 120V at 20A, a plug almost identical to the 2-20 type was used. The 2-20 plug fits into 5-20 and 6-20 sockets designed for a different voltage.

Walsall Gauge, UK

Unlike standard English forks BS 1363, the earth contact is horizontal and the phase and neutral contacts are vertical. This type of plug was used by the BBC, and is still sometimes used on the London Underground on low voltage networks.

Italian connector Bticino Magic security

Magic security connectors were developed by Bticino in the 1960s as an alternative to Europlugs or L-type connectors. Sockets of this type are almost rectangular, the plugs were inserted into a shaped slot, closed with a safety lid with the inscription “Magic”, which could only open when the corresponding plug was inserted into it. At least four models were produced: three single-phase general purpose connectors, rated respectively 10A, 16A and 20A, and a three-phase industrial connector rated 10A. Each connector had its own slot shape so that plugs could not be plugged into sockets that did not correspond to them. The contacts are located on both sides of the plug. The plug only connects to electricity when it is fully inserted into the outlet.

The obvious disadvantage of the system is that it is not compatible with Euroforks. Since household appliances were never sold with such a plug, after installing such sockets it was necessary to replace the plugs with the corresponding Magic security ones. However, the system Magic security was initially quite popular among consumers who valued security; The connectors used at that time were not sufficiently safe. When safety covers for type L sockets (VIMAR Sicury) were invented, Magic sockets almost went out of use.

In Italy, the Magic system has not been officially abandoned, and it is still available in the Bticino product catalog, although it is not popular.

In Chile, 10 Amp Magic connectors are commonly used in computer and laboratory environments, as well as in telecommunications plants, as a standard of reliability and safety, due to their polarization, difficulty of accidental disconnection, etc.

Brazil, using a mixture of Europlug and NEMA, later adopted it as the national standard NBR 14136 in 2001. A gradual transition is planned, starting in 2007 and ending in 2010 (retail stores and resellers can sell devices without time limits, but importers cannot import non-compliant devices, and manufacturers cannot sell them domestically).

Multi-standard sockets

Standard grounded Thai socket that accepts European two-pin plugs and US grounded and ungrounded plugs

Receptacles that accept different types of plugs can be found in different countries, in which market size or local market conditions make development of a specific plug standard impractical. These sockets accept plugs made to various European, Asian and North American standards. Because many plug standards are tied to their respective voltages, multistandard receptacles do not provide protection against damage to devices rated for other voltages. This forces users to know the voltage requirements for their devices as well as the prevailing voltage in the host country. With such sockets, you can safely use devices that automatically adjust to the desired voltage and frequency and do not require grounding.

These outlets may have one or more grounding holes for three-prong plugs. In correctly routed circuits, the ground pin is actually grounded; however, it is possible to determine whether this is so only with the help of special instruments. Even correctly wired sockets cannot guarantee a ground connection to all types of plugs, since it is difficult to create a socket of this design.

At three-phase connection electric stoves, the load on each phase separately is reduced due to the fact that each part of the stove is connected to a separate phase.

With a single-phase connection, the load on a single phase increases. The maximum power consumption of a typical modern electric stove is 8-10 kW, which at a voltage of 220V corresponds to a current of 36-45A. Conventional household wall sockets are designed, as a rule, for a current of no more than 16A, so the stove must be connected to the electrical network either in a permanent way or with a grounded connector designed for the appropriate current.

Different countries have different practices for connecting electric stoves.

For example, Swiss regulations dictate that equipment consuming current in excess of 16A must either be connected to the network in a permanent way, with suitable branch protection, or connected using an industrial connector suitable for the rated current.

The electrical safety regulations of some other countries do not say anything about the method of connecting electric stoves, and everyone is free to choose the connection method independently. Often the consumer himself buys the first non-standard pair of plug and socket for a specific electric stove, and it often happens that they are designed for a current of 25-32A, since the user relies on the fact that the stove usually never turns on at full power. The non-standard nature of the plug and socket is explained by the lack of national standards for connecting electric stoves.

See also

Links

• IEC Zone: Plugs and sockets Wikipedia

IEC connector is common name for a set of thirteen female connectors mounted on the power cord (hereinafter called connector) and thirteen pin connectors mounted on the device panel (called input), defined by the specification ... ... Wikipedia

This term has other meanings, see Rosette. This article lacks an introduction. Please add an introductory section that briefly describes the topic of the article. Contained ... Wikipedia

This article is about the design, technical features and history of the development of plug connectors. For plug connector standards adopted in different countries, see List of plug connector standards ... Wikipedia

This term has other meanings, see Voltage... Wikipedia

- (CEE 7/17), mechanically polarized version The contour plug (Type designation: CEE 7/17) has been developed to, like the Europlug, be used throughout Europe. It is used when the device does not require protective grounding, but ... Wikipedia

October 12th, 2017

This is really very inconvenient. Okay, people used to travel a little around the world, now it’s practically not a luxury. Remember, when household appliances assembled in Europe began to arrive in Russia, how many problems there were with our Soviet sockets. We bought adapters, they burned out. Only not long ago we finally got rid of this problem.

I was in Cyprus in the spring - there are very unusual British outlets there. You can’t buy adapters in a small town in Russia; upon arrival you had to run around, look for them, and overpay. I’m going to the Dominican Republic soon - and there are different outlets there again, American (sort of). Adapters will again have to be purchased locally and not in 1 copy.

And why...

In the era of electrification, inventors from different countries offered their own versions of optimal sockets; Different types of power generators were built all over the world.

Firstly, the struggle between technologies at the dawn of the development of electricity left its mark. We are talking about the confrontation between Thomas Edison and Nikola Tesla in the creation of direct and alternating current networks, respectively. Although we know that AC power plants ultimately won out, the DC infrastructure built in the US up until the 1920s (and in Stockholm into the 1950s) has to be maintained and used right up to the present day. .

Secondly, many inventors offered their own versions of optimal (in their opinion) sockets. For example, in 1904, American inventor Harvey Hubbel received a patent for the first electrical outlet. By its design, it was a kind of adapter between an electric cartridge and a plug. The adapter was screwed into the socket instead of a light bulb, and some electrical appliance was connected to it.

The German engineer Albert Büttner created the “Euro socket” we know today in 1926. And the first grounded socket was created by Philippe Labre in 1927.

And national companies involved in the installation of electrical networks supplied their devices suitable for these networks. Accordingly, different types of plug connectors and sockets were introduced and their own networks were designed. The developments of other countries were completely ignored.

Influenced the development of sockets and the availability of materials. For example, during World War II, Britain came up with a three-prong plug with a short copper fuse. This design made it possible to save copper reserves for military needs. Interestingly, the use of the three-prong plug in the UK was in stark contrast to the rest of Europe and even North America, where two-prong plugs were widely used and also varied in design, all due to poor communication in the early days development of electricity supply.

Now, according to one classification, there are 12 types of sockets, according to another - 15. Moreover, sockets of one type sometimes accept plugs of another. However, if you find out that the country you are going to has the same type of socket as at home, don’t rush to rejoice! This solves only half the problem. IN different parts Light voltage and current frequency may vary.

Classification of types of sockets and plugs in different countries of the world

The two most common standards are: European - 220-240 V at a frequency of 50 Hz and American - 100-127 V at a frequency of 60 Hz. You should not check what will happen if an electrical appliance operating on 100-127 V is plugged into an outlet with 220-240 V.

In some countries you should keep your ears open. For example, in most areas of Brazil, 127 V is used, but in the north of the country 220 V is found. And in Japan, the voltage is the same everywhere - 110 V, but the frequency is different: in the east 50 Hz is used, in the west - 60 Hz. The reason is simple: first, German-made generators with a frequency of 50 Hz were purchased for Tokyo, and soon after that American ones with a frequency of 60 Hz were supplied to Osaka.

Perhaps someday a single standard will be adopted. A universal socket for all types of plugs has already been developed. But for now it’s up to everyone to install it or not. In addition, we first need to come to a unified voltage standard. And this comes down to huge financial costs for the refurbishment and re-equipment of transformer substations, replacement of sockets and plugs.

* Voltage 100-127 V at a frequency of 60 Hz is used by the USA, Canada, Japan, Mexico, Cuba, Jamaica, partially Brazil and other countries.

* Voltage 220-240 V with a frequency of 50 Hz is used in most other countries, but even with the same parameters, the type of sockets can vary greatly.

Here brief description some of them:

Types A and B - american outlet

Type B differs from A by the presence of a third hole - it is intended for a grounding pin. Such sockets, as you can guess from the name, were invented in the USA and are widespread in North, Central and partly South America, as well as Japan and some other countries.

Types C and F - European socket

Just like A and B, types C and F differ from each other only in the presence of grounding - F has it. The European socket is used in most countries of the European Union, as well as in Russia and the CIS, Algeria, Egypt and many other countries.

Type G - British socket

In the UK, the socket has three flat holes, and this design appeared for a reason. The fact is that during World War II the country experienced a copper shortage. Therefore, a plug with a short copper fuse and three pins was developed. In addition to Great Britain, the same socket is used in Cyprus, Malta, Singapore and other countries that were influenced by the British Empire.

Type I - Australian socket

This type of socket can be found not only in Australia, but also in New Zealand, Fiji, Cook Islands, Kiribati, New Guinea, Samoa and sometimes in China, where types A and C are also common.

Type H - Israeli socket

Type H is used only in Israel and Palestine, and the pins of the plug can be either round or flat, depending on when the device was manufactured. The old equipment had a flat socket shape, but new sockets are suitable for two options.

Type K - Danish socket

This outlet can easily claim the title of “friendliest” in the world - its design resembles a smiling face. In addition to Denmark and Greenland, which is part of it, type K is used in Bangladesh and the Maldives - however, several types of sockets are common there.

Luckily, all these differences won't ruin your vacation or business trip—you just need to purchase the right adapter in advance.

Map showing the distribution of different types of sockets used around the world.(link to interactive map)

A world map shows the distribution of different types of sockets in use around the world. Countries using Types A and B are highlighted in red, countries using Types C and E/F are dark blue (which are 100% compatible with each other), countries using Type D are highlighted in brown, British Type G is in aqua, Israeli Types C and H are in pink. , countries using Australian type I are highlighted in yellow, countries using C and J in black, types C and K in gray, types C and L in orange, type M in purple in South Africa, type N in pale blue, and Thailand in dark green. Types C and O. Please note that this simplified overview only shows the most common plug type, and sometimes several systems in the same country.

For a complete and thorough overview of the electrical plugs used in each country, click .

List of countries around the world with corresponding plug and socket types, voltage and frequency. link worldstandards.eu/electrici...

A complete overview of all countries in the world and their respective plugs/sockets and voltages/frequencies used for home appliances. The table shows that most countries have electricity supplies between 220 and 240 volts (50 or 60 Hz), significantly superior to countries operating at 100 to 127 volts. The list also shows that types A and C are the most commonly used electrical plugs around the world.

Most countries have a clearly defined plug and voltage standard. However, many Latin American, African and Asian countries use a motley collection of often incompatible plugs, and sometimes the voltage differs from region to region. This situation makes it difficult for travelers to assess which adapter or transformer connector is needed for a trip. In this case, when the electricity situation in the country requires additional information, the name of the country in question is highlighted in red. This link will take you to detailed description: worldstandards.eu/electrici...

If you order various electrical appliances and devices through foreign online stores like Aliexpress or Ebay, then in the order parameters you will often find a selection option - US plug, UK plug, EU plug or AU plug. What is this and what does this designation mean?!

You probably know that there are different types of electrical outlets used around the world. So, to indicate the type of connector used on the device for connecting to electrical network special notations are used. What is their difference? Here are the four main types of plugs:

1. UK Plug- English or British socket, type G (three flat pins). Used in the UK, Singapore, Malta and Cyprus. Operating voltage 220-240 Volts.

2.AU Plug- Australian socket, type I. Used in Australia, New Guinea, New Zealand, Fiji, Samoa, China. Operating voltage 220-240 Volts.

3. EU Plug- the so-called “Euro” connector of the socket, type C and F (additionally 2 ground contacts). A regular European socket used in Russia, CIS countries, the European Union, as well as in many other countries (Turkey, Egypt, Algeria, Tunisia, etc.). The voltage used is 220-240 Volts at a frequency of 50 Hz.

4.US Plug— American socket, Type A (two vertical flat pins) and B (with a third hole for grounding). Used in the USA, as well as in the countries of South America and Japan. The voltage used is 100-127 Volts at a frequency of 60 Hz.

In addition, there are a number of less common types of electrical outlet plugs:

There are a total of 12 types of sockets in the world. Among them are Italian, Thai, African, Swiss, Israeli, etc. They are used much less frequently, but nevertheless they also have a place.

Try to imagine homo modernus without mobile phones, cameras, laptops, navigation systems and other gadgets? The answer is simple: it is impossible. Well, all these benefits of civilization cannot exist without “food”; they need recharging.
Therefore, beaches, parks, museums fade into the background, and the first thing a traveler should think about is what sockets and what voltage will be in the country where he is heading.
In most cases, the issue is resolved with the help of an adapter. But it can become useless if the voltage in the network is very different from the native, domestic one. For example, in Europe the voltage varies from 220 to 240 V; in the USA and Japan - from 100 to 127 V. If you don’t guess, you’ll burn your device.
Let's try to understand the intricacies of electrical engineering.

Voltage and frequency

By and large, only two levels of electrical voltage are used in the household network in the world:
European - 220 - 240 V and American - 100 - 127 V, and two AC frequencies - 50 and 60 Hz.

Voltage 220 - 240 V with a frequency of 50 Hz is used by most countries of the world.
Voltage 100 -127 V at a frequency of 60 Hz - in the USA, countries of North, Central and, partially, South America, Japan, etc.
However, there are variations, for example, in the Philippines, 220 V and 60 Hz, and in Madagascar, on the contrary, 100 V and 50 Hz, even within the same country, depending on the region, there may exist different standards, for example, in different parts of Brazil, Japan, Saudi Arabia, the Maldives.

Therefore, before you set off, collect as much information as possible about circuits and signals, the types of sockets used in the country and the voltage in the network.

Electrical sockets

There are a lot of sockets, plugs and options for connecting to the electrical network. But don’t be alarmed, there is no need to deal with everyone and look for an adapter for each one.
You need to remember (save, sketch, photograph) the 13 most used types of sockets, which are designated in Latin letters from A to M:

Type A - American electrical outlet and plug: two flat contacts parallel to each other. Used in most countries of North and Central America (USA, Canada, Mexico, Venezuela, Guatemala), in Japan, and almost everywhere where the mains voltage is 110 V.
Type B is a variation of the Type A connector, with an additional round ground pin. Typically used in the same countries as the Type A connector.
Type C - European socket and plug. It has two round parallel contacts (without grounding). This is the most popular socket in Europe, excluding England, Ireland, Malta and Cyprus. Used where the voltage is 220V.
Type D is the old British standard with three round contacts arranged in a triangle shape, with one of the contacts thicker than the other two, rated for maximum current. Used in India, Nepal, Namibia, Sri Lanka.
Type E is a plug with two round pins and a hole for the grounding pin, which is located in the socket of the socket. This type is now almost universally used in Poland, France and Belgium.
Type F - The standard is similar to Type E, but instead of a round ground pin there are two metal clamps on both sides of the connector. You will find such sockets in Germany, Austria, Holland, Norway, and Sweden.
Type G - British socket with three flat contacts. Used in England, Ireland, Malta and Cyprus, Malaysia, Singapore and Hong Kong.
Note. This type of outlet often comes with a built-in internal fuse. Therefore, if after connecting the device it does not work, then the first thing to do is check the condition of the fuse in the outlet.
Type H - has three flat contacts or, in more early version, round contacts are arranged in a V shape. Used only in Israel and the Gaza Strip. Not compatible with any other plug, designed for voltage values ​​of 220 V and current up to 16 A.
Type I - Australian socket: two flat contacts, as in the American type A connector, but they are located at an angle to each other - in the shape of the letter V. Also available in a version with a ground contact. Used in Australia, New Zealand, Papua New Guinea and Argentina.
Type J - Swiss plug and socket. It is similar to the Type C plug, but has an additional grounding pin in the middle and two round power pins. Used in Switzerland, Liechtenstein, Ethiopia, Rwanda and the Maldives.
Type K is a Danish socket and plug, similar to the European Type C, but with a ground pin located at the bottom of the connector. Used in Denmark, Greenland, Bangladesh, Senegal and the Maldives.
Type L - Italian plug and socket, similar to the European Type C socket, but with a round ground pin that is in the center, the two round power pins are arranged unusually in a line. Used in Italy, Chile, Ethiopia, Tunisia and Cuba.
Type M is an African socket and plug with three round pins arranged in a triangle shape, with the ground pin being clearly thicker than the other two. It is similar to the D-type connector, but has much thicker pins. The socket is designed to power devices with a current of up to 15 A. Used in South Africa, Swaziland and Lesotho.

A few words about various types of adapters.

The easiest way to be ready to put the plug into the socket is to purchase an adapter, converter or transformer in advance (it depends on what your needs are). In most hotels, if you contact them, they will select the device you need at the reception.

Adapters - combine your plug with someone else's socket without affecting the voltage, the most versatile device.
Converters - provide conversion of local power grid parameters, but for a short time, up to 2 hours. Suitable for small (camping) household appliances: hair dryer, razor, kettle, iron. Convenient on the road due to its small size and weight.
Transformers are more powerful, larger and more expensive voltage converters designed for continuous operation. Used for complex electrical appliances: computers, TVs, etc.

And at the end, an easy life hack on how to use an English socket without an adapter

Happy travels!

Sources: wikimedia.org, travel.ru, enovator.ru, personal experience.