View source for AC power plugs and sockets

{{Short description|Connector used to connect to mains power}}
{{About|the usage in domestic and light commercial environments|other types|Industrial and multiphase power plugs and sockets}}
{{Use dmy dates|date=March 2025}}{{Use Oxford spelling|date=March 2025}}
{{Multiple image |style="width:220px" |direction=vertical |image1=Schuko plug and socket.png |image2=French-power-socket.jpg |footer=Plugs and sockets may sometimes combine male and female contacts. Clockwise from top left: CEE&nbsp;7/4 (German) plug; a matching CEE&nbsp;7/3 socket with exposed earth (ground) projections on circumference of socket; CEE&nbsp;7/5 (French) socket with projecting earth pin}}
{{Electrical Wiring Sidebar}}

'''AC power plugs and sockets''' connect devices to [[mains electricity]] to supply them with [[electrical power]]. A '''plug''' is the connector attached to an electrically operated device, often via a cable. A '''socket''' (also known as a '''receptacle''' or '''outlet''') is fixed in place, often on the internal walls of buildings, and is connected to an [[Alternating current|AC]] electrical circuit. Inserting ("plugging in") the plug into the socket allows the device to draw power from this circuit.

Plugs and wall-mounted sockets for portable appliances became available in the 1880s, to replace connections to light sockets. A proliferation of types were subsequently developed for both convenience and protection from [[electrical injury]]. Electrical plugs and sockets differ from one another in [[voltage]] and [[electric current|current]] rating, shape, size, and connector type. Different standard systems of plugs and sockets are used around the world, and many obsolete socket types are still found in older buildings.

Coordination of technical standards has allowed some types of plug to be used across large regions to facilitate the production and import of electrical appliances and for the convenience of travellers. Some multi-standard sockets allow use of several types of plug. Incompatible sockets and plugs may be used with the help of adaptors, though these may not always provide full safety and performance.

== Overview of connections ==
[[Single-phase electric power|Single-phase]] sockets have receptacles for two power pins, one to carry the electrical current from the power source to the connected device (called ''live'', ''line'', or ''phase pin'') and another one to carry it back to the power source (called ''neutral pin''). Many sockets have a third receptacle or pin for a safety connection to earth ground. The plug is a [[gender of connectors and fasteners|''male'']] connector, usually with protruding pins that match the receptacles (''female'' contacts) in a socket. Some plugs also have a female contact, used only for the [[ground (electricity)|earth ground connection]]. Typically no energy is supplied to any exposed pins or terminals on the socket, hence the power pins are always part of the plug rather than the socket. In addition to the recessed contacts of the energised socket, plug and socket systems often have other safety features to reduce the risk of [[electric shock]] or damage to appliances.

== History ==
{{Main|History of AC power plugs and sockets}}

When commercial electric power was first introduced in the 1880s, it was used primarily for lighting. Other portable appliances (such as vacuum cleaners, electric fans, smoothing irons, and curling-tong heaters) were connected to light-bulb sockets. As early as 1885 a two-pin plug and wall socket format was available on the British market. By about 1910 the first three-pin earthed (grounded) plugs appeared. Over time other safety improvements were gradually introduced to the market. The earliest national standard for plugs and wall sockets was enacted in 1915 in the UK.{{citation needed|date=January 2019}}

== Safety features ==
{{More citations needed section|date=May 2021}}

=== Protection from accidental contact ===
Designs of plugs and sockets have gradually developed to reduce the risk of electric shock and fire. Plugs are shaped to prevent bodily contact with live parts. Sockets may be recessed and plugs designed to fit closely within the recess to reduce risk of a user contacting the live pins. Contact pins may be sheathed with insulation over part of their length, so as to reduce exposure of energized metal during insertion or removal of the plug. Sockets may have automatic shutters to stop foreign objects from being inserted into energized contacts.<ref name="ReferenceA">{{cite book |title=The History of Electric Wiring |author=John Mellanby |date=1957 |publisher=Macdonald |place=London}}</ref> Sockets are often set into a surround which prevents accidental contact with the live wires in the wall behind it. Some also have an integrated cover (e.g. a hinged flap) covering the socket itself when not in use, or a switch to turn off the socket.

=== Overcurrent protection ===
Some plugs, particularly the British ones, have a built-in [[Fuse (electrical)|fuse]] which breaks the circuit if too much current is passed.

=== Earthing (grounding) ===
A third contact for a connection to [[Ground (electricity)|earth]] is intended to protect against insulation failure of the connected device. Some early unearthed plug and socket types were revised to include an earthing pin or phased out in favour of earthed types. The plug is often designed so that the earth ground contact connects before the energized circuit contacts. The assigned IEC [[appliance classes|appliance class]] is governed by the requirement for earthing or equivalent protection. Class&nbsp;I equipment requires an earth contact in the plug and socket, while Class&nbsp;II equipment is unearthed and protects the user with [[Appliance classes#Class II|double insulation]].

{{anchor|Polarization}}

=== Polarisation ===
Where a "[[Ground and neutral|neutral]]" conductor exists in supply wiring, polarisation of the plug can improve safety by preserving the distinction in the equipment. For example, appliances may ensure that switches interrupt the live side of the circuit, or can connect the shell of a screw-base lampholder to neutral to reduce electric shock hazard. In some designs, polarised plugs cannot be mated with non-polarised sockets. In most [[NEMA connector#NEMA 1|NEMA&nbsp;1]] plugs, for example, the neutral blade is slightly wider than the hot blade, so it can only be inserted one way. Wiring systems where both circuit conductors have a significant potential with respect to earth do not benefit from polarised plugs.

=== Voltage rating of plugs and power cords ===
[[File:NEMA Plug Ratings.jpg|thumb|Ratings of NEMA&nbsp;5-15 (type&nbsp;B) plug marked on the label (left: 7&nbsp;A 125&nbsp;V), engagement face, and [[IEC 60320]] C13&nbsp;connector at the appliance end of the cord (centre, right: both 10&nbsp;A 125&nbsp;V)]]

Plugs and [[power cord]]s have a rated voltage and current assigned to them by the manufacturer. Using a plug or power cord that is inappropriate for the load may be a safety hazard. For example, high-current equipment can cause a fire when plugged into an extension cord with a current rating lower than necessary. Sometimes the cords used to plug in dual voltage 120&nbsp;V / 240&nbsp;V equipment are rated only for 125&nbsp;V, so care must be taken by travellers to use only cords with an appropriate voltage rating.
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== Extension ==
[[File:Tricklestar Plug Strip.jpg|thumb|A plug strip with two USB ports and built-in [[Surge protector|surge protection]]]]

Various methods can be used to increase the number or reach of sockets.

=== Extension cords ===
[[Extension cord]]s (extension leads) are used for temporary connections when a socket is not within convenient reach of an appliance's power lead. This may be in the form of a single socket on a flexible cable or a  [[power strip]] with multiple sockets. A power strip may also have switches, surge voltage protection, or overcurrent protection.
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=== Multisocket adaptors ===
<div style="width: auto; max-width: 50%; float: right; margin-left: 1em; border: 1px solid #a2a9b1;">
<gallery mode="packed" heights="140">
File:Adaptateur électrique multiprise CEE 7 04.jpg|A French CEE&nbsp;7 adaptor
File:Multisocket adaptor (once common).jpg|An old US multisocket adaptor
</gallery>
</div>

Multisocket adaptors (or "splitters") allow the connection of two or more plugs to a single socket. They are manufactured in various configurations, depending on the country and the region in which they are used, with various ratings. This allows connecting more than one electrical consumer item to one single socket and is mainly used for low power devices (TV&nbsp;sets, table lamps, computers, etc.).

They are usually rated for 6&nbsp;A, 10&nbsp;A, or 16&nbsp;A at 250&nbsp;V or for 15&nbsp;A or less at 125&nbsp;V. This is the general rating of the adaptor, and indicates the maximum total load in amperes, regardless of the number of sockets used (for example, if a 16&nbsp;A 250&nbsp;V adaptor has four sockets, it would be fine to plug four different devices into it that each consume 2&nbsp;A as this represents a total load of only 8&nbsp;A, whereas if only two devices were plugged into it that each consumed 10&nbsp;A, the combined 20&nbsp;A load would overload the circuit).

In some countries such adaptors are banned and are not available in shops, as they may lead to fires due to overloading them or can cause excessive mechanical stress to wall-mounted sockets. Adaptors can be made with ceramic, Bakelite, or other plastic bodies.
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== Cross-compatibility ==

=== Hybrid and universal sockets ===
<div style="width: auto; max-width: 50%; float: right; margin-left: 1em; border: 1px solid #a2a9b1;">
<gallery mode="packed" heights="140">
File:Multi plug.jpg|A so-called "universal socket", which meets no official standard<ref>{{cite web |url=https://www.extron.com/download/files/userman/Universal_AC_Outlet_68-1638-01_F.pdf |title=Universal AC Outlet • Setup Guide |publisher=Extron Electronics |location=Anaheim, CA |date=November 2017 |id=68-1638-01 Rev. F |access-date=21 May 2018 |archive-url=https://web.archive.org/web/20180516015051/https://www.extron.com/download/files/userman/Universal_AC_Outlet_68-1638-01_F.pdf |archive-date=16 May 2018 |url-status=dead}}</ref> but is intended to accept a number of different plug types
File:Thai socket.jpg|An earthed Thai socket that complies with figure&nbsp;4 of TIS&nbsp;166-2549. Although it accepts NEMA plugs, the Thai voltage is 220&nbsp;V and thus is electrically incompatible with devices designed only for 120&nbsp;V.
File:Chinasocket.jpg|Chinese dual socket accepting both unearthed two-pin (upper) and earthed three-pin (lower) plugs
</gallery>
</div>

"Hybrid", "multi-standard", or "universal" sockets are intended to accommodate plugs of two or more types. In some jurisdictions, they violate safety standards for sockets.<ref>{{cite web |url=https://www.spring.gov.sg/Building-Trust/Raising-Confidence/Safety-Tips-Alerts/Product-Safety-Alerts/Documents/SafetyAlert_Universal_Portable_Socket_Outlets.pdf |title=Alert noting non-compliant power strips |year=2009 |access-date=25 October 2019 |archive-url= https://web.archive.org/web/20160306184839/https://www.spring.gov.sg/Building-Trust/Raising-Confidence/Safety-Tips-Alerts/Product-Safety-Alerts/Documents/SafetyAlert_Universal_Portable_Socket_Outlets.pdf |archive-date=6 March 2016}}</ref><ref>{{cite web |url=http://www.pucsl.gov.lk/english/news/sri-lanka-sets-national-standard-for-plugs-and-socket-outlets-for-non-industrial-applications-2/ |title=Sri Lanka Sets National Standard for Plugs and Socket Outlets |website=Public Utilities Commission of Sri Lanka |access-date=25 October 2019 |quote=Standardized on Type&nbsp;G; sale of non-compliant sockets is banned as of August, 2018, and buildings must re-wire by August, 2038. |archive-url= https://web.archive.org/web/20190402014847/http://www.pucsl.gov.lk/english/news/sri-lanka-sets-national-standard-for-plugs-and-socket-outlets-for-non-industrial-applications-2/ |archive-date=2 April 2019 |url-status=dead}}</ref> Safety advocates, the United States Army,<ref name="jennings">{{cite web |url=http://www.almc.army.mil/alog/issues/MayJune12/Elelectrical_Safety.html |archive-url=https://web.archive.org/web/20150223190700/http://www.almc.army.mil/alog/issues/MayJune12/Elelectrical_Safety.html |archive-date=23 February 2015 |author=James S. Jennings |title=Army Sustainment: The Three Most Common Electrical Safety Issues in Deployed Environments}}</ref> and a manufacturer of sockets<ref>{{cite web |title=Universal Sockets Are Unsafe |url=http://www.interpower.com/ic/designers/white-papers/universal-sockets-are-unsafe.html |website=Interpower Corporation |publisher=Interpower |access-date=6 July 2018}}</ref> point out a number of safety issues with universal socket and adaptors, including voltage mismatch, exposure of live pins, lack of proper earth ground connection, or lack of protection from overload or short circuit. Universal sockets may not meet technical standards for durability, plug retention force, temperature rise of components, or other performance requirements, as they are outside the scope of national and international technical standards.

A technical standard may include compatibility of a socket with more than one form of plug. The Thai dual socket is specified in figure&nbsp;4 of TIS&nbsp;166-2549 and is designed to accept Thai plugs, and also Type&nbsp;A, B, and C&nbsp;plugs. Chinese dual sockets have both an unearthed socket complying with figure&nbsp;5 of GB&nbsp;1002-2008 (both flat pin and 4.8&nbsp;mm round pin), and an earthed socket complying with figure&nbsp;4 of GB&nbsp;1002-2008. The latter was removed from the 2021 revision of the Chinese standard,<ref name=GBT-1002-2021>{{cite web |last1=State Administration for Market Regulation |last2=Standardization Administration of China |title=GB/T 1002-2021: Single phase plugs and socket-outlets for household and similar purposes – Types, basic parameters and dimensions (English Version) |url=https://www.codeofchina.com/standard/GBT1002-2021.html |website=Code of China |date=11 October 2021 |author1-link=State Administration for Market Regulation |author2-link=Standardization Administration of China}}</ref> but such dual sockets can still be found in many existing installations.

Such Thai or Chinese dual sockets also accept plugs normally fitted to 120&nbsp;V appliances (e.g. 120&nbsp;V rated NEMA&nbsp;1-15 ungrounded plugs). This can cause an electrical incompatibility, since both countries supply residential power at 220&nbsp;V. These dual sockets also accept French and Schuko plugs (Types&nbsp;E and F), but unsafely: no earth contact is established and live pins may be exposed when a plug is partially inserted.<ref name=WorldSTDs/>

=== Swappable cables and plugs ===
{{Multiple image |total_width=200 |image1=AC wallplug adapter Apple-0830.jpg |image2=Connection cable CEE 7-16 to IEC 60320 C7.jpg |footer=Swappable plug (Apple) and IEC 60320 C7 cable}}

Commonly, manufacturers provide an [[IEC 60320]] inlet on an appliance, with a detachable [[power cord]] (mains flex lead) and appropriate plug in order to avoid manufacturing whole appliances, with the only difference being the type of plug. Alternatively, the plug itself can often be swappable using standard or proprietary connectors.
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=== Travel adaptors ===
[[File:Type M travel adaptor.jpg|thumb|upright|A travel adaptor for "Type M" (16&nbsp;A [[SANS 164#SANS 164-1|SANS&nbsp;164-1]]) sockets from South Africa]]

[[Adaptors]] between standards are not included in most standards, and as a result they have no formal quality criteria defined. Physical compatibility does not ensure that the appliance and socket match in frequency or voltage. Adaptors allow travellers to connect devices to foreign sockets, but do not change voltage or frequency. A [[voltage converter]] is required for electrical compatibility in places with a different voltage than the device is designed for. Mismatch in frequency between supply and appliances may still cause problems even at the correct voltage. Some appliances have a switch for the selection of voltage. Many modern devices use AC adapters that accept 100–240 V voltage at 50 or 60&nbsp;Hz, meaning they can be used anywhere in the world as long as a suitable plug adapter is used.
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== Standard types in present use ==
{{further|Mains electricity by country#Plugs}}

[[File:World map of electrical mains power plug types used.svg|thumb|450px|Types of power plugs and sockets used by country<br />{{legend-inline|#cd0000|A}} • {{legend-inline|#a50000|B, A}} • {{legend-inline|#73a0d0|C}} • {{legend-inline|#74d30e|D, M}} • {{legend-inline|#3165a5|E, C}} • {{legend-inline|#1a4988|F, C}} • {{legend-inline|#4d9b01|G}} • {{legend-inline|#cf5c00|H, C}} • {{legend-inline|#c5a100|I}} • {{legend-inline|#ae80aa|J, C}} • {{legend-inline|#5c3266|K, C}} • {{legend-inline|#764f7c|L, C}} • {{legend-inline|#ffd800|N, C}}]]
The plugs and sockets used in a given area are regulated by local governments.

The [[International Electrotechnical Commission]] (IEC) maintains a guide with letter designations for generally compatible types of plugs,<ref name="World Plugs">[http://www.iec.ch/world-plugs/ World Plugs] Retrieved on 27 March 2015.</ref> which expands on earlier guides published by the [[United States Department of Commerce]]. This is a ''de facto'' naming standard and guide to travellers. Some letter types correspond to several current ratings or different technical standards, so the letter does not uniquely identify a plug and socket within the type family, nor guarantee compatibility. Physical compatibility of the plug and socket does not ensure correct voltage, frequency, or current capacity. Not all plug and socket families have letters in the IEC guide, but those that have are noted in this article, as are some additional letters commonly used by retail vendors.<ref name="ECO">The letter system first appeared in such guides in 1967 ([http://babel.hathitrust.org/cgi/pt?id=uc1.b4263654 ''Electric Current Abroad''.] [[United States Department of Commerce]], 1967. Retrieved on 14 December 2013.) which designated types A two-pin US, B (BS&nbsp;546), and C (BS&nbsp;1363). The 1984 edition ([http://babel.hathitrust.org/cgi/pt?id=uc1.b4263653 ''Electric Current Abroad''.] [[United States Department of Commerce]], 1984. Retrieved on 14 December 2013.) uses the letters A to G in the same manner as they are used today, and the last revision of the print series was in 1998 ({{cite web |year=2002 |title=Electric Current Abroad |url=http://trade.gov/publications/pdfs/current2002FINAL.pdf |publisher=US Department of Commerce, International Trade Administration (retrieved 9 October 2015)}}). The [[International Trade Administration]] of the US Department of Commerce now publishes a web version: [http://www.trade.gov/mas/ian/ecw/ Electric Current Worldwide], which differs slightly from the IEC list and from Wikipedia's list at [[Mains electricity by country]].</ref>

In Europe, [[European Committee for Electrotechnical Standardization|CENELEC]] publishes a list of approved plug and socket technical standards used in the member countries.<ref>{{cite web |url=ftp://ftp.cencenelec.eu/CENELEC/TCs/61/PlugsSockets.pdf |archive-url=https://web.archive.org/web/20210808100440/ftp://ftp.cencenelec.eu/CENELEC/TCs/61/PlugsSockets.pdf |archive-date=2021-08-08 |url-status=dead |title=FTP link |work=ftp.cencenelec.eu }} Plugs and socket types in each CENELEC country, Retrieved 15 February 2012.</ref>
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=== Australasian AS/NZS 3112 and compatible plugs (Type I)<span class="anchor" id="Type I"></span> ===
A number of countries in [[Oceania]] as well as China and Argentina use a plug that has two flat pins at an angle, forming a V-shape, as well as a flat vertical grounding pin. While the exact pin dimensions and the polarity vary between different countries, these plugs and sockets are all compatible to each other and are known as ''Type&nbsp;I''.

==== Argentina IRAM 2073 and 2071 ====
[[File:I plug.jpg|thumb|Type&nbsp;I grounded plug and socket, both rated for 10&nbsp;A. Insulating sleeves around the power pins are optional in Argentina and in this case missing. The socket is installed with the earth receptacle down, as usual in Argentina.]]

The plug and socket system used in [[Argentina]] is defined by several standards of the [[Instituto Argentino de Normalización y Certificación|Argentine Normalization and Certification Institute]] (IRAM). IRAM&nbsp;2071 defines two sockets that have the same form factor, but differ in size and rating.<ref>{{cite web |last1=IRAM |author1-link=Instituto Argentino de Normalización y Certificación |title=IRAM 2071:2009 – Tomacorrientes bipolares con toma de tierra para uso en instalaciones fijas domiciliarias, de 10 A y 20 A, 250 V de corriente alterna |url=https://catalogo.iram.org.ar/#/normas/detalles/2640 |website=IRAM: Catálogo de Cursos y Normas |access-date=26 March 2025 |date=12 November 2009}}</ref> The smaller, more common socket is rated for 10&nbsp;[[ampere|A]]. The larger variant, rated for 20&nbsp;A, is mostly used for higher-power appliances such as air conditioners. IRAM&nbsp;2073 defines the corresponding plugs used for [[Appliance classes#Class I|Class&nbsp;I]] appliances (that require earthing).<ref>{{cite web |last1=IRAM |author1-link=Instituto Argentino de Normalización y Certificación |title=IRAM 2073:2009 – Fichas bipolares con toma de tierra para usos domiciliarios y similares, de 10 A y 20 A, 250 V de corriente alterna |url=https://catalogo.iram.org.ar/#/normas/detalles/2642 |website=IRAM: Catálogo de Cursos y Normas |access-date=26 March 2025 |date=12 November 2009}}</ref> The plug and socket system has an earthing pin and two flat current-carrying pins forming an inverted V-shape (120°).

The pins for the 10&nbsp;A version measure {{convert|6.25|by|1.55|mm|in|3|abbr=on}}. The power pins are set at 30° to the vertical with a distance of {{convert|7.92|mm|in|3|abbr=on}} from their centres to the centre of the plug; they are {{convert|18.2|mm|in|3|abbr=on}} long. The earthing pin is {{convert|21.4|mm|in|3|abbr=on}} long and placed below the plug centre at a distance of {{convert|10.31|mm|in|3|abbr=on}}. The pins of the 20&nbsp;A version are larger – {{convert|8.0|by|1.9|mm|in|3|abbr=on}} – and placed further away from the centre of the plug – {{convert|9.53|mm|in|3|abbr=on}} for the power pins, {{convert|11.1|mm|in|3|abbr=on}} for the earthing pin. At {{convert|21.8|mm|in|3|abbr=on}}, the earthing pin is a bit longer, while the power pins are a bit shorter at {{convert|17.8|mm|in|3|abbr=on}}.

There is also an unearthed version of the 10{{nbsp}}A plug, defined by IRAM&nbsp;2063, that lacks an earthing pin and can be used with [[Appliance classes#Class II|Class&nbsp;II]] appliances.<ref>{{cite web |last1=IRAM |author1-link=Instituto Argentino de Normalización y Certificación |title=IRAM 2063:2009 – Fichas bipolares sin toma de tierra para usos domiciliarios y similares, de 10 A, 250 V de corriente alterna |website=IRAM: Catálogo de Cursos y Normas |url=https://catalogo.iram.org.ar/#/normas/detalles/2629 |access-date=27 March 2025 |date=12 November 2009}}</ref> 20{{nbsp}}A plugs, on the other hand, must always provide earthing.

Insulating sleeves around the upper parts of the power pins are allowed, but not required. When used, they significantly reduce the risk of electric shock from accidentally touching the pins of a partially inserted plug. Because the pins of the 20&nbsp;A plug are placed farther apart than those of the 10&nbsp;A plug, the two Argentine plug types are mutually incompatible. It is not possible to insert a 20&nbsp;A plug into a 10&nbsp;A socket or vice versa.{{CN|date=May 2025}} <!-- Actually any Argentine will know this is completely untrue -->

The most important difference from the Australasian and Chinese plugs is that the Argentine plug is wired with the live and neutral contacts reversed.<ref>{{cite web |title=Argentina, Australia, and China Standard 10A/250V Plugs & Sockets Have Similar Features, But What are Some Critical Differences? |url=https://blog.interpower.com/infopower/argentina-australia-and-china-standard-10a/250v-plugs-sockets-have-similar-features-what-are-some-critical-differences |website=InfoPower |date=27 October 2020 |access-date=9 March 2025 |language=en}}</ref> In Argentina, when the earth contact is positioned downward, the live (line) contact is on the right side of the socket,<ref>{{cite web |title=Plugs and sockets in Argentina and Uruguay |url=https://www.plugsocketmuseum.nl/Argentina1.html |website=Museum of Plugs and Sockets |access-date=23 March 2025}}</ref> while in Australasia and China it is on the left (assuming the same orientation).

In Brazil, Type&nbsp;I–style plugs and sockets are still commonly used in old installations for high-power appliances like air conditioners, dishwashers, and household ovens. These are often called "Argentine plugs" and are indeed physically identical to the IRAM plugs rated for 20&nbsp;A, though they might have been developed independently on the basis of the American [[NEMA connector#NEMA L10|NEMA&nbsp;10-20]] standard (which uses the same form factor). While these plugs are sometimes used for normal single-phase power and wired in the same way as in Argentina, some are wired for [[Split-phase electric power|split-phase power]] with two "hot" (or phase) wires and a neutral wire, but no earth connection. Care must therefore be taken that the same wiring scheme is used in the socket and in the plug, since otherwise the equipment would surely be damaged. In newer installations, the 20&nbsp;A version of the Type&nbsp;N plug, adopted by Brazil as national standard NBR&nbsp;14136, is generally preferred.<ref>{{cite web |title=Brazilian plugs and sockets |url=https://www.plugsocketmuseum.nl/Brazil1.html |website=Museum of Plugs and Sockets |access-date=27 March 2025}}</ref>

==== Australian/New Zealand standard AS/NZS 3112 ====
{{Main|AS/NZS 3112}}
<div style="width: auto; max-width: 50%; float: right; margin-left: 1em; display: flex; border: 1px solid #a2a9b1;">
<div style="display: flex; flex-direction: column;">
<gallery mode="packed" heights="150">
File:Australian Dual Socket Outlet.jpg|Australasian switched three-pin (10&nbsp;A) dual socket outlet, the most commonly found variant
</gallery>
<gallery mode="packed" heights="150">
File:Aust AC plug.jpg|Standard Australian 10&nbsp;A power plug with insulated pins
</gallery>
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<gallery mode="packed" heights="400">
File:Australian mains socket styles for different current ratings.jpg|10&nbsp;A, 15&nbsp;A, 20&nbsp;A, 25&nbsp;A, and 32&nbsp;A single-phase sockets. Each socket accepts plugs of equal or lesser current rating.
</gallery>
</div>

This Australian/New Zealand standard is used in Australia, New Zealand, Fiji, Tonga, Solomon Islands, and Papua New Guinea.<ref>AS/NZS&nbsp;3112:2004, ''Approval and test specification&nbsp;– Plugs and socket-outlets'', [[Standards Australia]] and Standards New Zealand</ref> The plug shape and basic dimensions are identical to the 10&nbsp;A plug used in Argentina. The Australasian standard defines a series of plugs and sockets for devices drawing up to 10, 15, 20, 25 and 32&nbsp;A that are one-way compatible. All sockets accept plugs of equal or lower current ratings, but not higher. For example, a 10&nbsp;A plug will fit all sockets but a 20&nbsp;A plug will fit only 20, 25 and 32&nbsp;A sockets.

In all plugs, the power pins are set at 30° to the vertical with a distance of {{convert|7.92|mm|in|3|abbr=on}} from their centres to the centre of the plug, while the earthing pin is placed below the plug centre at a distance of {{convert|10.31|mm|in|3|abbr=on}} – exactly the same dimensions as used by the Argentine 10&nbsp;A plug. The three flat pins all measure {{convert|6.35|by|1.63|mm|in|3|abbr=on}} – very slightly larger than in Argentina. The length of the power pins is {{convert|17.06|mm|in|3|abbr=on}}, while the earthing pin has a length of {{convert|19.94|mm|in|3|abbr=on}} – somewhat shorter than in Argentina.

In the 15&nbsp;A plug, the height of the earth pin is increased from 6.35 to {{convert|9.08|mm|in|3|abbr=on}}, while the dimensions of the power pins remain the same. In the 20&nbsp;A plug, however, their height is increased in the same way, so that the surface dimensions of the three pins are again identical. In the 25&nbsp;A version, the earthing pin takes the shape of an inverted L (an extra bar is added at the top end), and in the 32&nbsp;A version it takes the shape of a sideways U (extra bars are added at both ends).

In general, only 10&nbsp;A and 15&nbsp;A socket outlets are likely to be encountered in domestic or commercial installations. 20&nbsp;A sockets are rare and higher rated ones are very rare. An unearthed version of the 10&nbsp;A plug with two angled power pins but no earthing pin is used with double-insulated appliances, but sockets and higher-rated plugs always include an earth contact. In New Zealand, PDL&nbsp;940 "tap-on" or "piggy-back" plugs are available which allow a second 10&nbsp;A plug to be fitted to the rear of the plug. In Australia these piggy-back plugs are now available only on pre-made extension leads.

A novel feature of modern Australian socket outlets is a snap-fitting surround for the socket, covering the screws that affix the socket to the wall, and extending all the way around the socket periphery. Australia is unique in having electrical rules that stipulate that only licenced electricians may remove the socket from the wall, so the easily removed outer cover facilitates repainting the wall without exposing power and incurring the expense of engaging an electrician to remove and replace the sockets.

Australia's standard plug/socket system was originally codified as standard C112 (floated provisionally in 1937, and adopted as a formal standard in 1938), which was based on [[History of AC power plugs and sockets#American 125&nbsp;V, 15&nbsp;A / 250&nbsp;V, 10&nbsp;A "Australian" style|a design]] patented by [[Harvey Hubbell]] and was superseded by [[AS/NZS 3112|AS&nbsp;3112]] in 1990. The requirement for insulated pins was introduced in the 2004 revision.<ref>{{cite web |title=Mains Plug Insulated Pins: Australian Standards AS/NZS3112:2000 & AS/NZS3112:2004 |url=https://www.accesscomms.com.au/ref_insulated-pins/ |website=Access Communications Australia |access-date=29 March 2025}}</ref> The current version is ''AS/NZS&nbsp;3112:2017''.<ref>{{cite web |title=AS/NZS 3112:2017: Approval and test specification – Plugs and socket-outlets |url=https://www.standards.govt.nz/shop/asnzs-31122017 |website=Standards New Zealand |access-date=30 March 2025 |date=24 August 2017}}</ref>

==== China GB&nbsp;2099.1 and GB&nbsp;1002 (Type A & I) ====
[[File:China's 3-pin sockets.jpg|thumb|upright=0.9|Chinese three-pin socket and compound socket which also accepts NEMA and Europlug (right), and a less common, larger 16&nbsp;A version (left)]]

The standard for Mainland [[China|Chinese]] plugs and sockets (excluding [[Hong Kong]] and [[Macau]]) is set out in [[Standardization Administration of China|GB]]&nbsp;2099.1 and GB&nbsp;1002. As part of China's commitment for entry into the [[World Trade Organization|WTO]], the new CPCS (Compulsory Product Certification System) has been introduced, and compliant Chinese plugs have been awarded the [[China Compulsory Certificate|CCC Mark]] by this system. The plugs are three-wire, earthed, rated for 10 or 16&nbsp;A, 250&nbsp;V, and are chiefly used for Class&nbsp;I applications. The pins of the 10&nbsp;A version are {{convert|1.5|mm|in|3|abbr=on}} thick by {{convert|6.4|mm|in|3|abbr=on}} wide; the centres of the power pins are placed {{convert|7.9|mm|in|3|abbr=on}} from the plug centre, while the centre of the earth pin is {{convert|10.3|mm|in|3|abbr=on}} away. In both plug types, the live and neutral pins are {{convert|18|mm|in|3|abbr=on}} long, while the earth pin is {{convert|21|mm|in|3|abbr=on}} long. This makes the 10&nbsp;A version compatible with Argentine and Australasian 10&nbsp;A sockets, as their dimensions are nearly identical.<ref name=gb1002>{{cite web |place=PRC |url=http://www.cnapc.org/System/eWebEditor/uploadfile/20140506164304211.pdf |title=National Standard of the People's Republic of China GB 1002-2008, Single phase plugs and socket-outlets for household and similar purposes – Types, basic parameters and dimensions |publisher=General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China (AQSIQ) |year=2008 |url-status=dead |archive-url=https://web.archive.org/web/20160804084314/http://www.cnapc.org/System/eWebEditor/uploadfile/20140506164304211.pdf |archive-date=4 August 2016}}</ref>

Except for the pin length, all dimensions of the 16&nbsp;A version are slightly larger. Its pins are {{convert|1.8|by|8.1|mm|in|3|abbr=on}}; the centres of the power pins are placed {{convert|9.55|mm|in|3|abbr=on}} from the plug centre, while the centre of the earth pin is {{convert|11.1|mm|in|3|abbr=on}} away.<ref name=gb1002/> This makes this plug compatible with the 20&nbsp;A sockets used in Argentina. It is, however, incompatible with Chinese 10&nbsp;A sockets as well as all Australasian sockets because of the different pin spacing.

Many three-pin sockets in China include a physical lockout preventing access to the active and neutral terminals unless an earth pin (which is slightly longer than the other two pins) is entered first. Hence such sockets will not accept the 10&nbsp;A-rated unearthed Class II plugs sold in Argentina and Australasia. The Chinese 16&nbsp;A plug exists, however, also in an unearthed Class II variant that includes an unwired dummy earth pin used only to open shutter. No such variant exists of the 10&nbsp;A plug.<ref name=gb1002/>

China also uses American/Japanese NEMA&nbsp;1-15 sockets and plugs for Class II appliances (however, polarized plugs with one prong wider than the other are not accepted). Older versions of GB&nbsp;1002 also defined a socket type that accepts Europlugs (type&nbsp;C), but this hybrid socket was removed from the 2021 revision of the standard.<ref name=GBT-1002-2021/> The voltage at a Chinese socket of any type is 220&nbsp;V.

In China, sockets typically have the earth contact above the power pins, while in Argentina and Australasia it is usually positioned below them. While Australasian plugs have insulating sleeves around the upper part of their power pins, that is not the case for most existing Chinese plugs, hence their pins may become live while there is still a large enough gap between the faces of the plug and socket to allow a finger to touch the pin. Since 2022, insulating sleeves are also allowed on plugs sold in China;<ref>{{cite web |title=注意啦！新版家用插头插座标准将于2022年11月1日起正式实施-行业资讯 |url=https://www.zrlklab.com/show-38-1363.html |website=zrlklab.com |access-date=7 March 2025 |archive-url=https://web.archive.org/web/20220523043712/https://www.zrlklab.com/show-38-1363.html |archive-date=23 May 2022 |language=zh}}</ref> they will be mandatory from 2027.<ref>{{cite web |title=GB 1002-2024单相插头的带电插销是否强制要求施加绝缘护套？ |url=https://www.163.com/dy/article/JG5P75LG0552L9R6.html |website=163.com |access-date=7 March 2025 |language=zh |date=4 November 2024}}</ref>
{{clear}}

=== British and compatible standards ===
{{Main|AC power plugs and sockets: British and related types}}
The polarity of all grounded British sockets is standardized: earth is at the top and live is at the right of the socket. This convention is also followed in other countries using these plugs and sockets.<ref>{{cite web |title=Understanding European, Scandinavian and world wide plugs and sockets |url=https://toughleads.co.uk/pages/world-wide-plugs-and-sockets |website=Tough Leads |access-date=22 March 2025 |language=en}}</ref>

==== BS 546 and related types (Type D and M)<span class="anchor" id="Type D"></span><span class="anchor" id="Type M"></span> ====
[[File:BS 546 Plugs - 15A 5A 2A.png|thumb|BS&nbsp;546 plugs. Left to right: 15&nbsp;A, 5&nbsp;A and 2&nbsp;A.]]

<!--editors: Additional details should be added to [[AC power plugs and sockets - British and related types]].-->
BS 546, "Two-pole and earthing-pin plugs, socket-outlets and socket-outlet adaptors for AC (50-60&nbsp;Hz) circuits up to 250&nbsp;V" describes four sizes of plug rated at 2&nbsp;A, 5&nbsp;A (Type&nbsp;D), 15&nbsp;A (Type&nbsp;M) and 30&nbsp;A. The plugs have three round pins arranged in a triangle, with the larger top pin being the earthing pin. The plugs are polarised and unfused. Plugs are non-interchangeable between current ratings. Introduced in 1934, the BS&nbsp;546 type has mostly been displaced in the UK by the BS&nbsp;1363 standard. According to the IEC,<ref name="iec">{{cite web |title=World Plugs |url=http://www.iec.ch/worldplugs/list_bytype.htm |url-status=dead |access-date=27 August 2014 |website=International Electrotechnical Commission (IEC) |archive-date=25 October 2014 |archive-url=https://web.archive.org/web/20141025174324/http://www.iec.ch/worldplugs/list_bytype.htm}}</ref> some 40&nbsp;countries use Type&nbsp;D and 15&nbsp;countries use Type&nbsp;M. Some, such as India and South Africa, use standards based on BS&nbsp;546.

==== BS 1363 (Type G)<span class="anchor" id="Type G"></span> ====
<div style="width: auto; max-width: 50%; float: right; margin-left: 1em; border: 1px solid #a2a9b1;">
<gallery mode="packed" heights="140">
File:Uk 13a double socket.jpg|BS&nbsp;1363 sockets
File:BS1363 Plug 04.jpg|BS&nbsp;1363 plug with fuse compartment visible
</gallery>
</div>

<!--editors: Additional details should be added to [[AC power plugs and sockets - British and related types]].-->
BS 1363 "13 A plugs, socket-outlets, adaptors and connection units"<ref>BS''&nbsp;''1363 (1995), BS''&nbsp;''1363: 1995 "13 A plugs, socket-outlets, adaptors and connection units", British Standards Institute.</ref> is the main plug and socket type used in the United Kingdom. According to the [[International Electrotechnical Commission|IEC]]<ref name="World Plugs" /> it is also used in over 50 countries worldwide. Some of these countries have national standards based on BS&nbsp;1363, including: [[Bahrain]], [[Hong Kong]],<ref>{{cite web |last=Electrical and Mechanical Services Department |title=Guidance Notes for the Electrical Products (Safety) Regulation |url=https://www.emsd.gov.hk/filemanager/en/content_444/GN-ElectricalProductsSafetyRegulation2019.pdf |website=emsd |edition=2019}}</ref> [[Republic of Ireland|Ireland]], [[Cyprus]], [[Malaysia]], [[Malta]], [[Saudi Arabia]], [[Singapore]], [[Sri Lanka]], and [[United Arab Emirates|UAE]].

This plug has three rectangular pins forming an isosceles triangle. The BS&nbsp;1363 plug has a [[Fuse (electrical)|fuse]] rated to protect its flexible cord from overload and consequent fire risk. Modern appliances may only be sold with a fuse of the appropriate size pre-installed.

{{anchor|bs4573}}

==== BS 4573 (UK shaver) ====
{{Main|AC power plugs and sockets: British and related types#BS 4573 (UK shaver)}}
[[File:ShaverPlugUK.jpg|thumb|right|upright=0.4|BS&nbsp;4573 plug]]

<!--editors: Additional details should be added to [[AC power plugs and sockets - British and related types]].-->
The United Kingdom, Ireland, and Malta use the BS&nbsp;4573 two-pin plug and socket for electric shavers and toothbrushes.<ref>BS''&nbsp;''4573 (1970), ''British Standard Specification for two-pin reversible plugs and shaver socket-outlets'', British Standards Institution.</ref> The plug has insulating sleeves on the pins. Although similar to the [[Europlug]] Type&nbsp;C, the diameter and spacing of the pins are slightly different and hence it will not fit into a Schuko socket. There are, however, two-pin sockets and adaptors which will accept both BS&nbsp;4573 and Europlugs.
{{clear}}

=== CEE 7 standard ===
{{Main|CEE 7 standard AC plugs and sockets}}
[[File:Stopcontact.jpg|thumb|upright=0.6|CEE&nbsp;7/1 wall socket, accepts CEE&nbsp;7/2 (unearthed) plug and also CEE&nbsp;7/4, CEE&nbsp;7/6 and CEE&nbsp;7/7 (earthed) plugs.]]

The International Commission on the Rules for the Approval of Electrical Equipment ([[IECEE]]) was a standards body which published ''Specification for plugs and socket-outlets for domestic and similar purposes'' as CEE Publication 7 in 1951. It was last updated by Modification 4 in March 1983.<ref>{{cite web|url= http://webstore.iec.ch/webstore/webstore.nsf/ArtNum_PK/31105|title=IECEE CEE-7 ed2.0 |access-date=1 March 2015}}</ref> CEE&nbsp;7 consists of general specifications and standard sheets for specific connectors.

Standard plugs and sockets based on two round pins with centres spaced at 19&nbsp;mm are in use in Europe, most of which are listed in IEC/TR&nbsp;60083 "Plugs and socket-outlets for domestic and similar general use standardized in member countries of IEC."<ref>{{cite web|title=IEC/TR 60083: Technical Report|url= http://webstore.iec.ch/preview/info_iec60083%7Bed6.0%7Db.pdf |access-date=2 March 2015}}</ref> EU countries each have their own regulations and national standards; for example, some require child-resistant shutters, while others do not. [[CE marking]] is neither applicable nor permitted on plugs and sockets.

==== CEE 7/1 unearthed socket and CEE 7/2 unearthed plug ====
CEE&nbsp;7/1 unearthed sockets accept CEE&nbsp;7/2 round plugs with {{convert|4.8|by|19|mm|in|3|abbr=on}} pins. Because they have no earth connections they have been or are being phased out in most countries. Some countries still permit their use in dry areas, while others allow their sale for replacements only. Older sockets are so shallow that it is possible to accidentally touch the live pins of a plug. CEE&nbsp;7/1 sockets also accept CEE&nbsp;7/4, CEE&nbsp;7/6 and CEE&nbsp;7/7 plugs without providing an earth connection. The earthed CEE&nbsp;7/3 and CEE&nbsp;7/5 sockets do not allow insertion of CEE&nbsp;7/2 unearthed round plugs.

{{anchor|CEE 7/4 plug|Type F}}

==== CEE 7/3 socket and CEE 7/4 plug (German "Schuko"; Type F)<span class="anchor" id="Type F"></span> ====
{{Main|Schuko}}
[[File:Schuko plug and socket.png|thumb|left|upright=.9|Schuko plug (CEE&nbsp;7/4) and socket (CEE&nbsp;7/3)]]
[[File:Schuko (CEE 7-3) socket-outlets, with and without shutters.jpg|thumb|upright=.6|Two Schuko (CEE&nbsp;7/3) socket-outlets manufactured by Busch-Jaeger Elektro GmbH: the lower has (black) protective shutters; the upper does not, revealing internal metal contacts.]]

The CEE&nbsp;7/3 socket and CEE 7/4 plug are commonly called ''[[Schuko]]'', an abbreviation for ''Schutzkontakt'', ''Protective contact'' to earth ("Schuko" itself is a registered [[trademark]] of a [[Registered association (Germany)|German association]] established to own the term). The socket has a circular recess with two round holes and two earthing clips that engage before live pin contact is made. The pins are {{convert|4.8|by|19|mm|in|3|abbr=on}}. The Schuko system is unpolarised, allowing live and neutral to be reversed. The socket accepts Europlugs and CEE&nbsp;7/17 plugs and also includes CEE&nbsp;7/7. It is rated at 16&nbsp;A. The current German standards are [[Deutsches Institut für Normung|DIN]]&nbsp;49441 and DIN&nbsp;49440. The standard is used in Germany and several other European countries and on other continents. Some countries require child-proof socket shutters; the DIN&nbsp;49440 standard does not have this requirement.

The plug is used in most or many countries of Europe, Asia, and Africa, as well as in the countries of [[South Korea]], [[Peru]], [[Chile]] and Uruguay.{{Citation needed|date=August 2019}} The few European countries not using it at all are [[Belgium]], [[Czech Republic]], [[Cyprus]], [[Ireland]], [[Liechtenstein]], [[Switzerland]], and the [[UK]], or not using it predominantly are [[Denmark]], [[Faroe Island]], [[France]], [[Italy]], [[Monaco]], [[San Marino]], [[Slovakia]].

==== CEE 7/5 socket and CEE 7/6 plug (French; Type E) ====
{{anchor|CEE 7/5 socket|CEE 7/6 plug|Type E}}
[[File:French-power-socket.jpg|French socket (CEE&nbsp;7/5)|thumb|upright=.9]]
[[File:French Plug CEE 7 6.jpg|Rewireable French plug (CEE&nbsp;7/6, now rare)|thumb|upright=.9]]

[[France|French]] standard NF C 61-314 defines the CEE&nbsp;7/5 socket and CEE&nbsp;7/6 plug, (and also includes CEE&nbsp;7/7, 7/16 and 7/17 plugs). The socket has a circular recess with two round holes. The round earth pin projecting from the socket connects before the energized contacts touch. The earth pin is centred between the apertures, offset by {{convert|10|mm|in|3|abbr=on}}. The plug has two round pins measuring {{convert|4.8|by|19|mm|in|3|abbr=on}}, spaced {{convert|19|mm|in|3|abbr=on}} apart and with an aperture for the socket's projecting earth pin. This standard is also used in [[Belgium]], [[Poland]], the [[Czech Republic]], [[Slovakia]] and some other countries.

Although the plug is polarised, CEE&nbsp;7 does not define the placement of the live and neutral, and different countries have conflicting standards for that. For example, the French standard NF C 15-100 requires live to be on the right side, while Czech standard ČSN 33 2180 requires it to be on the left side of a socket. Thus, a French plug when plugged into a Czech socket (or a Czech plug when plugged into a French socket) will always have its polarity reversed, with no way for the user to remedy this situation apart from rewiring the plug. One approach for resolving this situation is taken in Poland, where CEE&nbsp;7/5 sockets are typically installed in pairs, the upper (upside-down) one having the "French" polarity and the lower one having the "Czech" polarity, so that the user can choose what to plug where.

CEE&nbsp;7/4 (Schuko) plugs are not compatible with the CEE&nbsp;7/5 socket because of the round earthing pin permanently mounted in the socket; CEE&nbsp;7/6 plugs are not compatible with Schuko sockets due to the presence of indentations on the side of the recess, as well as the earth clips. CEE&nbsp;7/7 plugs have been designed to solve this incompatibility by being able to fit in either type of socket.<ref>{{cite web |title=Museum of Plugs and Sockets: CEE 7 standard/title> |url=https://plugsocketmuseum.nl/CEE-standard.html |access-date=21 May 2024 |website=plugsocketmuseum.nl}}</ref>

Sales and installations of 7/5 sockets are legally permitted in [[Denmark]] since 2008, but the sockets are hard to find in physical stores,<ref>{{cite web |url=https://www.greenline.dk/lk-stikkontakt-1-modul-med-pindjord-hvid-15420 |title=LK stikkontakt 1 modul med pindjord, hvid |access-date=13 November 2023 |language=da |publisher=Greenline.dk}}</ref> and installation is exceedingly rarely performed.

{{anchor|CEE 7/7 plug}}

==== CEE 7/7 plug (compatible with E and F) ====
[[File:CEE 7-7.jpg|Hybrid CEE&nbsp;7/7 plug|thumb|upright=.9]]

The CEE&nbsp;7/7 plug fits in either French or Schuko sockets. It is rated at 16A and looks similar to CEE&nbsp;7/4 plugs, but with earth contacts to fit both CEE&nbsp;7/5 sockets and CEE&nbsp;7/3 ones. It is polarised when used with a French-style CEE&nbsp;7/5 socket, but can be inserted in two ways into a CEE&nbsp;7/3 socket. However, with the French socket it is not specified whether the live connection is on the left or right, as this can vary between countries.

Earthed appliances are typically sold fitted with non-rewireable CEE&nbsp;7/7 plugs attached, though rewireable versions are also available. This plug can be inserted into a Danish Type K socket, but the earth contact will not connect.

{{anchor|CEE 7/16 plug}}

==== CEE 7/16 plugs ====
The CEE&nbsp;7/16 unearthed plug is used for unearthed appliances. It has two round {{convert|4|by|19|mm|in|3|abbr=on}} pins, rated at 2.5&nbsp;A. There are two variants.

===== CEE&nbsp;7/16 Alternative I =====
Alternative I is a round plug with cutouts to make it compatible with CEE&nbsp;7/3 and CEE&nbsp;7/5 sockets. (The similar-appearing CEE&nbsp;7/17 has larger pins and a higher current rating.) This alternative is seldom used.

===== CEE&nbsp;7/16 Alternative II "Europlug" (Type C)<span class="anchor" id="Type C"></span><span class="anchor" id="Europlug"></span> =====
{{Main|Europlug}}
[[File:Euro-Flachstecker 2.jpg|thumb|upright=.9|Europlug]]

Alternative II, popularly known as the [[Europlug]], is a flat 2.5&nbsp;A-rated plug defined by Cenelec standard EN&nbsp;50075 and national equivalents. The Europlug is not rewirable and must be supplied with a flexible cord. It can be inserted in either direction, so live and neutral are connected arbitrarily. To improve contact with socket parts the Europlug has slightly flexible pins which converge toward their free ends.

There is no socket defined to accept only the Europlug. Instead, the Europlug fits a range of sockets in common use in Europe. These sockets include CEE&nbsp;7/1, CEE&nbsp;7/3 (German/"Schuko") and CEE&nbsp;7/5 (French). Most Israeli, Swiss, Danish and Italian sockets were designed to accept pins of various diameters, mainly 4.8&nbsp;mm, but also 4.0&nbsp;mm and 4.5&nbsp;mm, and are usually fed by final circuits with either 10&nbsp;A or 16&nbsp;A overcurrent protection devices.<ref>{{cite web |url=http://www.legrand.com/files/fck/File/pdf/Guide-International.pdf |title=International electrical standards and regulations |access-date=16 November 2015 |publisher=Legrand |pages=14, 22, 30}}</ref>

Although the standard does not permit extension cables and does not define any socket-outlets, unauthorized extension cables and sockets are manufactured.

UK shaver sockets are designed to accept BS&nbsp;4573 shaver plugs while also accepting Europlugs. In this configuration, the connection supply is only rated at 200&nbsp;mA. It is not permissible within the UK for the shaver socket to be fitted and used for a higher rated current draw than the 200&nbsp;mA maximum.

The Europlug is also used in parts of the Middle East, Africa, South America, and Asia.

{{anchor|CEE 7/17 plug}}

==== CEE 7/17 unearthed plug ====
[[File:CEE 7-17 plug.jpg|thumb|upright=.75|Hybrid unearthed CEE&nbsp;7/17 plug]]

This is a round plug compatible with CEE&nbsp;7/1, CEE&nbsp;7/3, and CEE&nbsp;7/5 sockets. It has two round pins measuring {{convert|4.8|by|19|mm|in|3|abbr=on}}. The pins are not sheathed, in contrast to e.g. CEE&nbsp;7/16 Europlugs. It may be rated at either 10&nbsp;A or 16&nbsp;A. A typical use is for appliances that exceed the 2.5&nbsp;A rating of CEE&nbsp;7/16 Europlugs. It may be used for unearthed Class&nbsp;II appliances (and in South Korea for all domestic non-earthed appliances). It is also defined as the Class&nbsp;II plug in Italian standard CEI&nbsp;23-50.

It is sometimes called a contour plug, because its collar contour follows that of the socket's recess. The collar prevents accidental contact with the non sheathed pins when inserting or removing the plug in a recessed socket.

It can be inserted into Israeli SI&nbsp;32 outlets with some difficulty, as well as Danish (type K) ones. The Soviet [[GOST 7396#Group C|GOST&nbsp;7396]] standard includes both the CEE&nbsp;7/17 and the CEE&nbsp;7/16 variant&nbsp;II plug.
{{clear}}

=== Danish plug (Type K)<span class="anchor" id="Type K"></span> ===
[[File:107-2-D1 - Danish electrical plugs - Studio 2011.jpg|thumb|upright|Danish 107-2-D1, standard DK 2-1a, with round power pins and a half-round earth pin]]

This [[Denmark|Danish]] standard plug is described in the Danish Plug Equipment Section 107-2-D1 Standard sheet (SRAF1962/DB&nbsp;16/87&nbsp;DN10A-R). Like in most European plugs, the power pins of Danish plugs are {{convert|19|mm|in|abbr=on}} long and spaced {{convert|19|mm|in|abbr=on}} apart, with a diameter of {{convert|4.8|mm|in|abbr=on}}. The earthing pin is part of the plug (in contrast to French and Schuko plugs); it is D-shaped, {{convert|14|mm|in|abbr=on}} long, and offset from the power pins by {{convert|13|mm|in|abbr=on}}. It is {{convert|4|mm|in|abbr=on}} thick with a diameter of {{convert|6.5|mm|in|abbr=on}}. Sockets and plugs are rated for 16{{nbsp}}A.<ref>{{cite web |title=Power plug & outlet Type K |url=https://www.worldstandards.eu/electricity/plugs-and-sockets/k/ |website=WorldStandards.eu |access-date=18 February 2025 |date=4 January 2025}}</ref> The Danish standard provides for sockets to have child-resistant shutters. Sockets are polarised in the same way as British ones: if earth is at the bottom, live is at the left of the socket.<ref>{{cite web |title=Mains Line Plugs, 210A Series Type 186 – Specifications |url=https://www.bpro-solutions.com/partnerportal/EU/en/p/000000000000107592/downloadDocument?documentCode=0000000000000001000366942&application=PDF |website=B.Pro Solutions |format=PDF |access-date=21 March 2025}}</ref><ref>{{cite web |title=Classic Danish types |url=https://www.plugsocketmuseum.nl/Danish3.html |website=Museum of Plugs and Sockets |access-date=21 March 2025}}</ref>

Europlugs (CEE&nbsp;7/16) can be safely used with Danish sockets. Physically the sockets also accept earthed CEE&nbsp;7/4 (Schuko), CEE&nbsp;7/6 (French), and CEE&nbsp;7/7 (Schuko-French hybrid) plugs, but no earth connection will be established.

[[File:Gniazdo el z przelacznikiem (ubt).JPG|thumb|left|upright=.55|Old Danish unearthed and switched socket]]

Traditionally all Danish sockets were equipped with a switch to prevent touching live pins when connecting/disconnecting the plug. Today, sockets without switch are allowed, but they must be recessed to prevent touching the live pins. Since the early 1990s earthed sockets have been required in all new electric installations in Denmark. Older sockets need not be earthed, but all sockets, including old installations, must be protected by [[Residual-current device|earth-fault interrupters]] (HFI or HPFI in Danish) by 1 July 2008.

[[File:DanishComputerPlugSocket-DK-2-5a.png|thumb|upright|Socket for the tilted flattened pins and half-round earth pin of a Danish computer plug]]

Since 1 July 2008, French-style CEE&nbsp;7/5 sockets may also be installed in Denmark.<ref>{{Citation |place=DK |language=da |url=http://www.sik.dk/Professionelle/El-branchen/Love_og_regler/index.aspx?id=b7f014a1-4b6b-4173-95e5-82efb87bcebf |publisher=Sik |title=5. udgave af Stærkstrømsbekendtgørelsen afsnit 107-2-D1 "Stikpropper og stikkontakter for danske systemer" |url-status=dead |archive-url=https://web.archive.org/web/20081207093431/http://www.sik.dk/Professionelle/El-branchen/Love_og_regler/index.aspx?id=b7f014a1-4b6b-4173-95e5-82efb87bcebf |archive-date=7 December 2008}}</ref><ref>{{cite web |last=Mølsted |first=Henning |date=12 September 2006 |title=Slut med dansk monopol på stikkontakter |url=https://ing.dk/artikel/slut-med-dansk-monopol-pa-stikkontakter-70837 |access-date=2 December 2022 |website=[[Ingeniøren]] |language=da}}</ref> Since 15 November 2011, CEE&nbsp;7/3 (Schuko) sockets may be installed as well,<ref>{{Citation |place=DK |language=da |url=https://www.retsinformation.dk/Forms/R0710.aspx?id=139163 |publisher=Retsinformation |title=BEK nr 1041 af 10/11/2011: Bekendtgørelse om stærkstrømsbekendtgørelsen, afsnit&nbsp;6C, særlige krav til anvendelse af stikpropper og stikkontakter i installationer}}</ref> but Type K remains by far the most common socket in Danish homes as of January 2024. French and Schuko sockets were allowed because little electrical equipment sold to private users is equipped with a Danish plug. In Europe, devices are usually sold with the Europlug CEE&nbsp;7/16 and hybrid plug CEE&nbsp;7/7, as these fit in most countries. However, in Denmark this often leads to the situation that the protective earth is not connected.<ref name="worldstandards.eu">{{cite web |url=https://www.worldstandards.eu/electricity/plug-voltage-by-country/denmark/ |title=Power plug, socket & mains voltage in Denmark |language=en |date=5 January 2025 |access-date=21 February 2025 |website=WorldStandards.eu}}</ref> Newssites and industry magazines have warned that, due to the lack of grounding, plugging a hybrid (or French or Schuko) plug directly into a Type K socket can give noticeable electric shocks to the point of pain,<ref name="worldstandards.eu"/><ref>{{cite web |url=https://ing.dk/artikel/kronik-danske-stikkontakter-er-en-dyr-tikkende-bombe |title=Kronik: Danske stikkontakter er en dyr tikkende bombe |language=da |access-date=3 January 2024 |date=8 May 2014 |publisher=ING.dk}}</ref> be dangerous to the point of hospitalizing,<ref>{{cite web |url=https://www.sik.dk/erhverv/elinstallationer-og-elanlaeg/vejledninger/ulykker/hvad-sker-der-kroppen-ved-elulykker|title=Hvad sker der med kroppen ved elulykker? |language=da |access-date=3 January 2024 |publisher=Sikkerhedsstyrelsen |quote=''En kvinde fik stød af en defekt kaffemaskine. Kaffemaskinen var monteret med Schuko-stikprop, men installationen var beskyttet med fejlstrømsafbryder, som slog fra. Kvinden var indlagt i et døgn.''}}</ref> or even be life-threatening.<ref>{{cite web |url=https://www.avisen.dk/pas-paa-hvidevare-stik-er-livsfarlige_182036.aspx |title=Pas på - hvidevare-stik er livsfarlige |language=da |access-date=3 January 2024 |date=25 August 2012 |publisher=Avisen.dk}}</ref><ref>{{cite web |url=https://ing.dk/artikel/spoerg-scientariet-hvorfor-giver-min-roeremaskine-stoed |title=Spørg Scientariet: Hvorfor giver min røremaskine stød? |language=da |access-date=3 January 2024 |date=24 February 2018 |publisher=ING.dk}}</ref><ref>{{cite web |url=https://taenk.dk/forbrugerliv/bolig/haarde-hvidevarer-maa-du-selv-tilslutte |title=Hårde hvidevarer: Må du selv tilslutte? |language=da |access-date=3 January 2024 |date=13 February 2020 |publisher=Forbrugerrådet Tænk}}</ref><ref>{{cite web |url=https://samvirke.dk/artikler/tilslut-jordforbindelsen-paa-dine-elektriske-apparater-og-undgaa-stoed-og-kortslutning |title=Tilslut jordforbindelsen på dine elektriske apparater og undgå stød og kortslutning |language=da |access-date=3 January 2024 |date=29 April 2019 |publisher=Samvirke.dk}}</ref>

A variation (standard DK&nbsp;2-5a) of the Danish plug is for use only on surge protected computer sockets. It fits into the corresponding computer socket and the normal socket, but normal plugs deliberately do not fit into the special computer socket. The plug is often used in companies, but rarely in private homes. There is another variation for hospital equipment with a rectangular left pin, which is used for life support equipment.
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{{anchor|Type N}}

=== IEC 60906-1 (Type N) ===
{{Main|IEC 60906-1}}
[[File:IEC 60906-1 (type N ) socket.jpg|thumb|upright=.5|left|IEC 60906-1 (type&nbsp;N) socket]]
[[File:SANS 164-2 plug 05.jpg|thumb|Three-pin 16&nbsp;A plug conforming to South African Standard SANS&nbsp;164-2]]

In 1986, the International Electrotechnical Commission published IEC 60906-1, a specification for a plug and socket that look similar, but are not identical, to the Swiss plug and socket. This standard was intended to one day become common for all of Europe and other regions with 230&nbsp;V mains, but the effort to adopt it as a European Union standard was put on hold in the mid-1990s.<ref>{{cite web |url=http://www.iec.ch/worldplugs/history.htm |title=International standardization of electrical plugs and socket-outlets for domestic use |location=CH |publisher=[[International Electrotechnical Commission|IEC]] |access-date=20 May 2017 |archive-date=12 August 2018 |archive-url=https://web.archive.org/web/20180812205914/http://www.iec.ch/worldplugs/history.htm |url-status=dead}}</ref>

The plug and socket are rated 16&nbsp;A 250&nbsp;V&nbsp;AC and are intended for use only on systems having nominal voltages between 200&nbsp;V and 250&nbsp;V&nbsp;AC. The plug pins are 4.5&nbsp;mm in diameter, live and neutral are on centres 19&nbsp;mm apart. The earth pin is offset by 3.0&nbsp;mm. The live pin is on the right when looking at a socket with the earth pin offset up. Shutters over the live and neutral pins are mandatory.

The first country to have officially adopted the standard is [[South Africa]] (as [[SANS 164#SANS 164-2|SANS&nbsp;164-2]]).<ref>{{cite web |publisher=Crabtree |location=ZA |url=http://www.crabtree.co.za/modules_fe/layout1/displayFullNews.asp?newsID=19 |title=When Less is More... |url-status=dead |archive-url=https://web.archive.org/web/20100706213636/http://www.crabtree.co.za/modules_fe/layout1/displayFullNews.asp?newsID=19 |archive-date=6 July 2010}}</ref><ref>{{cite web |publisher=EE publishers |location=ZA |url=http://www.eepublishers.co.za/images/upload/04%20G%20IT%20-%20SANS.pdf |title=SANS 164 standards: a working group perspective |url-status=dead |archive-url=https://web.archive.org/web/20120320000042/http://www.eepublishers.co.za/images/upload/04%20G%20IT%20-%20SANS.pdf |archive-date=20 March 2012}}</ref> [[Paraguay]] has also adopted it as national standard (PNA-IEC 60906-1),<ref name=PNA-IEC-60906-1>{{cite web |title=PNA-IEC 60906-1 |url=https://erp.intn.gov.py/shop/product/pna-iec-60906-1-ctn-02-8224 |website=Instituto Nacional de Tecnología, Normalización y Metrología |access-date=24 March 2025 |language=es |date=November 2022}}</ref> but so far its application is voluntary,<ref>{{cite web |title=INTN presentó norma de los nuevos tomacorrientes que deberán utilizarse en Paraguay |url=https://amigocamionero.com.py/intn-presento-norma-de-los-nuevos-tomacorrientes-que-deberan-utilizarse-en-paraguay/ |website=Amigo Camionero |access-date=24 March 2025 |language=es |date=25 November 2022}}</ref> and {{As of|2025|03|lc=y}}, there is no indication that sockets of this type are commonly installed in the country.

[[Brazil]] developed a plug resembling IEC 60906-1 as the national standard under specification NBR&nbsp;14136.<ref name="ABNT"/> The NBR&nbsp;14136 standard has two versions, neither of which has pin dimensions or ratings complying with IEC 60906-1. Use at 127&nbsp;V is permitted by NBR&nbsp;14136, which is against the intention of IEC 60906-1.

==== South African standard SANS 164-2 ====
{{Main|SANS 164-2}}
[[File:SANS 164-2 sockets.jpg|thumb|upright=.85|South African SANS 164-2, quadruple socket]]

South Africa adopted IEC 60906-1 as its national standard, SANS&nbsp;164-2, in 1992. The standard specifies both a 2-pin unearthed and 3-pin earthed plug system, equivalent to IEC Type&nbsp;N. SANS&nbsp;164-2 was designated the "preferred standard" in 2013, and South Africa is in the process of transitioning to it as the dominant system, expected to be completed by 2025 to 2035.

The SANS&nbsp;164-2 system is compatible with the SANS&nbsp;164-5 Europlug, commonly used in the country. This transition aims to improve electrical safety and standardization, aligning South Africa with international plug and socket systems.

==== Brazilian standard NBR 14136 ====
{{See also|IEC 60906-1#Brazilian NBR 14136 standard}}
[[File:NBR 14136 plugs and outlet.jpg|thumb|upright=1.1|Two-pin charger, three-pin 10&nbsp;A plug and 10&nbsp;A socket-outlet conforming to Brazilian Standard NBR&nbsp;14136]]
[[File:Tomada_Brasileira_-_NBR_14136,_20A,_250V.jpg|thumb|upright=.85|Brazilian 20 ampere socket]]

Brazil, which had been using mostly Europlugs as well as NEMA&nbsp;1-15 and NEMA&nbsp;5-15 plugs, adopted a (non-compliant) variant of IEC 60906-1 as the national standard in 1998 under specification NBR&nbsp;14136 (revised in 2002).<ref name="ABNT">{{Citation |title=NBR 14136:2002&nbsp;– Plugues e tomadas para uso doméstico e análogo&nbsp;– Padronização |publisher=ABNT |trans-title=Plugs and socket-outlets for household use and similar purposes – Specification |language=pt |place=BR |year=2002}}</ref> These are used for both 220-volt and 127-volt regions of the country, despite the IEC 60906-2 recommendation that NEMA&nbsp;5-15 be used for 120&nbsp;V connections. There are two types of sockets and plugs in NBR&nbsp;14136: one for 10&nbsp;A, with a 4.0&nbsp;mm pin diameter, and another for 20&nbsp;A, with a 4.8&nbsp;mm pin diameter.<ref>{{cite web |publisher=Projeto de redes |url=http://www.projetoderedes.com.br/artigos/artigo_norma_abnt_14136.php |title=Norma ABNT NBR 14136:2002 |language=pt |location=BR}}</ref> This differs from IEC&nbsp;60906-1 which specifies a pin diameter of 4.5&nbsp;mm and a rating of 16&nbsp;A. NBR&nbsp;14136 does not require shutters on the apertures, a further aspect of non-compliance with IEC 60906-1. NBR&nbsp;14136 was not enforced in that country until 2007, when its adoption was made optional for manufacturers. It became compulsory on 1 January 2010.

Few private houses in Brazil have an earthed supply, so even if a three-pin socket is present it is not safe to assume that all three terminals are actually connected. Most large domestic appliances were sold with the option to fit a flying earth tail to be locally earthed, but many consumers were unsure how to use this and so did not connect it. The new standard has an earth pin, which in theory eliminates the need for the flying earth tail.<ref>{{cite web |url=http://www.inmetro.gov.br/qualidade/pluguestomadas/perguntas.asp |title=Plugues e Tomadas |access-date=1 December 2015 |url-status=dead |archive-url=https://web.archive.org/web/20160305013445/http://www.inmetro.gov.br/qualidade/pluguestomadas/perguntas.asp |archive-date=5 March 2016}} Aquele fiozinho que tem pendurado atrás da minha geladeira, vai desaparecer?</ref>

Due to their smaller pin diameter, Brazilian plugs rated for 10{{nbsp}}A also fit into Brazilian sockets rated for 20{{nbsp}}A and South African sockets rated for 16{{nbsp}}A. 20{{nbsp}}A plugs do not fit into 10{{nbsp}}A sockets, which is as intended. However, if the Brazilian and South African variants are mixed, due to receptacle tolerances it might be possible to insert a 16{{nbsp}}A plug into a 10{{nbsp}}A socket or a 20{{nbsp}}A plug into a 16{{nbsp}}A socket, which could overload the socket.<ref>{{cite web |title=IEC 60906-1:2009 |url=https://webstore.iec.ch/en/publication/3882 |website=International Electrotechnical Commission (IEC) |at=Standard sheet 1-1 (gives the receptacle diameter as 5{{nbsp}}mm for a pin diameter of 4.5{{nbsp}}mm) |language=en}}</ref>
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=== Israel SI32 (Type H) ===
[[File:Israeli-type-H-plugs-and-socket.jpg|thumb|upright=.9|Two Israeli plugs and one socket. The left plug is the old standard; the one on the right is the 1989 revision.]]
[[File:Israel, type H, mains socket polarity.jpg|thumb|left|upright=.6|Israeli socket polarity, with wire color coding]]

The plug defined in [[SI 32|SI&nbsp;32]] ([[IS16A-R]]) is used only in [[Israel]], the [[Gaza Strip]] and the [[West Bank]]. There are two versions: an older one with flat pins, and a newer one with round pins.<ref name=PlugSocketIsrael>{{cite web |url=https://www.plugsocketmuseum.nl/Israeli1.html |title=SI 32 standard Israeli plugs and sockets |website=PlugSocketMuseum.nl |access-date=8 June 2018}}</ref>

The pre-1989 system has three flat pins in a Y-shape, with live and neutral {{convert|19|mm|in|2|abbr=on}} apart. The plug is rated at 16&nbsp;A. In 1989 the standard was revised, with three round {{convert|4.5|mm|in|3|abbr=on}} pins in the same locations designed to allow the socket to accept both older and newer Israeli plugs, and also non-grounded Europlugs (often used in Israel for equipment which does not need to be grounded and does not use more current than the Europlug is rated for).<ref name=PlugSocketIsrael/> Pre-1989 sockets which accept only old-style plugs have become very rare in Israel.

Sockets have a defined polarity; looking at the front, neutral is to the left, ground at the bottom, and live to the right.<ref>{{cite web |url=http://www2.moital.gov.il/cmstamat/rsrc/tkina/SI32Part1-1.pdf |title=SI 32 part 1.1, draft, 3/2013. Figure #203 |page=14 |work=The Standards Institution of Israel |language=he |access-date=19 September 2015|url-status=dead |archive-url=https://web.archive.org/web/20141106225827/http://www2.moital.gov.il/cmstamat/rsrc/tkina/SI32Part1-1.pdf |archive-date=6 November 2014}}</ref>
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=== Italy (Type L) ===
{{Multiple image |align=right |width=200 |direction=vertical |image1=Ita_plug_16A_10A.jpg |image2=Italian sockets.jpg |footer=Side by side comparison of Italian CEI&nbsp;23-50 S&nbsp;17 and S&nbsp;11 plugs and sockets rated 16&nbsp;A (left) and 10&nbsp;A (right)}}

Italian plugs and sockets are defined by the standard CEI&nbsp;23-50 which superseded CEI&nbsp;23-16. This includes models rated at 10&nbsp;A and 16&nbsp;A that differ in contact diameter and spacing (see below for details).<ref>{{Cite web |url=https://www.power-plugs-sockets.com/italy/ |title=Italy |website =Power Plugs and Sockets of the World}}</ref> Both are symmetrical, allowing the live and neutral contacts to be inserted in either direction. This plug is also commonly used in Chile and Uruguay.

# 10 A plugs and socket: Pins which are 4&nbsp;mm in diameter, the centres spaced 19&nbsp;mm apart. The 10&nbsp;A three-pin earthed rear entry plug is designated CEI&nbsp;23-50 S&nbsp;11 (there are also two side-entry versions, SPA&nbsp;11 and SPB&nbsp;11). The 10&nbsp;A two-pin unearthed plug is designated CEI&nbsp;23-50 S&nbsp;10. The 10&nbsp;A three-pin earthed socket is designated CEI&nbsp;23-50 P&nbsp;11, and the 10&nbsp;A two-pin unearthed socket is designated CEI&nbsp;23-50 P&nbsp;10. Both 10&nbsp;A sockets also accept CEE&nbsp;7/16 (Europlugs).
# 16 A plug and socket: Pins which are 5&nbsp;mm in diameter, the centres spaced 26&nbsp;mm apart. The 16&nbsp;A three-pin earthed rear entry plug is designated CEI&nbsp;23-50&nbsp;S&nbsp;17 (there are also two side-entry versions, SPA&nbsp;17 and SPB&nbsp;17). The 16&nbsp;A two-pin unearthed plug is designated CEI&nbsp;23-50 S&nbsp;16. The 16&nbsp;A three-pin earthed socket is designated CEI&nbsp;23-50 P&nbsp;17, there is not a 16&nbsp;A two-pin unearthed socket. The 16&nbsp;A socket used to be referred to as ''per la forza motrice''<ref>{{cite book |last=De Cesco |date=1975 |pages=70–71 |title=''Manuali pratici del far da sé Acqua Luce Gas'' |language=it}}</ref> (for electromotive force, see above) or sometimes (inappropriately) ''industriale'' (industrial) or even ''calore'' (heat).

The two standards were initially adopted because up to the second half of the 20th century in many regions of Italy electricity was supplied by means of two separate consumer connections – one for powering illumination and one for other purposes – and these generally operated at different voltages, typically 127&nbsp;V (a single phase from 220&nbsp;V three-phase) and 220&nbsp;V (a single phase from three-phase 380&nbsp;V or two-phase from 220&nbsp;V three-phase). The electricity on the two supplies was separately metered, was sold at different tariffs, was taxed differently and was supplied through separate and different sockets.{{sfn|De Cesco|1975|pp=56–57}} Even though the two electric lines (and respective tariffs) were gradually unified beginning in the 1960s (the official, but purely theoretical date was the summer of 1974){{sfn|De Cesco|1975|p=93}} many houses had dual wiring and two electricity meters for years thereafter; in some zones of Lazio the 127&nbsp;V network was provided for lighting until 1999. The two gauges for plugs and sockets thus became a [[de facto standard]] which is now formalized under CEI&nbsp;23-50. Some older installations have sockets that are limited to either the 10&nbsp;A or the 16&nbsp;A style plug, requiring the use of an adaptor if the other gauge needs to be connected. Numerous cross adaptors were used.

Almost every appliance sold in Italy nowadays is equipped with CEE&nbsp;7/7 (German/French), CEE&nbsp;7/16 or CEE&nbsp;7/17 plugs, but the standard Italian sockets will not accept the first and the third ones since the pins of the CEE&nbsp;7/7 and CEE&nbsp;7/17 plugs are thicker (4.8&nbsp;mm) than the Italian ones (4&nbsp;mm); besides the pins are not sheathed and forcing them into a linear Italian socket may lead to electric shock. Adaptors are standardized in Italy under CEI&nbsp;23-57 which can be used to connect CEE&nbsp;7/7 and CEE&nbsp;7/17 and plugs to linear CEI&nbsp;23-50 sockets.

Europlugs are also in common use in Italy; they are standardized under CEI&nbsp;23-34 S 1 for use with the 10&nbsp;A socket and can be found fitted to Class&nbsp;II appliances with low current requirement (less than 2.5&nbsp;A).

The current Italian standards provide for sockets to have child-resistant shutters ("Sicury" patent).<ref>{{cite web |url=http://www.vimar.de/de/de/article/article/detail/id/1259 |title=Bestreben Nach Sicherheit {{pipe}} Vimar |publisher=Vimar.de |access-date=12 March 2013}}</ref>
{{clear}}

==== Italian multiple standard sockets ====
[[File:Vimar-brand universale (all purpose) socket.jpg|thumb|A CEI&nbsp;23-50&nbsp;P&nbsp;40 socket (Italian adapted ''Schuko'') next to a CEI&nbsp;23-50&nbsp;17/11 (''Bipasso'') socket in a modern installation]]
[[File:4box side 4B.AM.H21 28-14.jpg|thumb|''4box side'' socket combining 1 Schuko and 2 CEI&nbsp;23-50&nbsp;P&nbsp;17/11 ''bipasso'' (Italian type plugs)]]
[[File:ForzaLuce1950.jpg|thumb|upright=.75|Old adaptor from ''forza'' to 2&nbsp;× ''luce'' and 1&nbsp;× ''forza'']]

In modern installations in Italy (and in other countries where Type&nbsp;L plugs are used) it is usual to find sockets that can accept more than one standard.

The simplest type, designated CEI&nbsp;23-50 P&nbsp;17/11, has a central round hole flanked by two figure-8 shaped holes, allowing the insertion of CEI&nbsp;23-50 S&nbsp;10 (Italian 10&nbsp;A plug unearthed), CEI&nbsp;23-50 S&nbsp;11 (Italian 10&nbsp;A plug earthed), CEI&nbsp;23-50 S&nbsp;16 (Italian 16&nbsp;A plug unearthed), CEI&nbsp;23-50 S&nbsp;17 (Italian 16&nbsp;A plug earthed) and CEE&nbsp;7/16 (Europlug). The advantage of this socket style is its small, compact face; its drawback is that it accepts neither CEE&nbsp;7/7 nor CEE&nbsp;7/17, very commonly found in new appliances sold in Italy. Vimar brand claims to have patented this socket first in 1975<ref>{{Citation |url=http://www.vimar.eu/index.php?l=it&module=articles&class=articles&event=__default&menu_item_id=134&content=20 |title=La ricerca della sicurezza. Ma la ricerca continua | publisher=Vimar |access-date=22 January 2009 |language=it}}</ref> with their ''Bpresa'' model; however soon other brands started selling similar products, mostly naming them with the generic term ''presa bipasso'' (twin-gauge socket) that is now of common use.

A second type is called CEI&nbsp;23-50 P&nbsp;30 and looks like a Schuko socket, but adds a central earthing hole (optional according to CEI&nbsp;23-50, but virtually always present). This design can accept CEE&nbsp;7/4 (German), CEE&nbsp;7/7 (German/French), CEE&nbsp;7/16, CEE&nbsp;7/17 (''Konturenstecker'', German/French unearthed), CEI&nbsp;23-50 S&nbsp;10 and CEI&nbsp;23-50 S&nbsp;11 plugs. Its drawback is that, while it is twice as large as a normal Italian socket, it still does not accept Italian 16&nbsp;A plugs; therefore this socket is relatively rarely installed.

A more flexible hybrid socket is called CEI&nbsp;23-50 P&nbsp;40. This socket, which is quickly becoming the standard in Italy along with CEI&nbsp;23-50 P&nbsp;17/11, accepts the same plugs as P&nbsp;30 and additionally Italian S&nbsp;16 and S&nbsp;17 plugs. A small drawback is that it does not accept SPA&nbsp;11, SPB&nbsp;11, SPA&nbsp;17 and SPB&nbsp;17 side-entry plugs; however almost no appliance is sold with these types, which are mainly used to replace existing plugs.
{{clear}}

=== North America, Central America and IEC 60906-2<span class="anchor" id="NEMA"></span>  ===
{{Main|NEMA connector}}
<div style="width: auto; max-width: 50%; float: right; margin-left: 1em; border: 1px solid #a2a9b1;">
<gallery mode="packed" heights="150">
File:Domestic AC Type B USA.jpg|'''Left:''' NEMA&nbsp;5-15 plug. '''Right:''' "Decora"-style duplex socket, with ground-pin up orientation specified in NECA&nbsp;130-2010, centre. Photos are different scale – parallel blades are on {{convert|1/2|in|adj=on|1}} centres.
File:NEMA 5-15 Outlet 120V-15A.jpg|Ordinary duplex socket mounted in ground-pin down orientation.
</gallery>
</div>

Most of North America and Central America, and some of South America, use connectors standardized by the [[National Electrical Manufacturers Association]] (NEMA). The devices are named using the format NEMA n-mmX, where ''n'' is an identifier for the configuration of pins and blades, ''mm'' is the maximum current rating, and ''X'' is either P for plug or R for receptacle. For example, NEMA&nbsp;5-15R is a configuration type&nbsp;5 receptacle supporting 15&nbsp;A. Corresponding ''P'' and ''R'' versions are designed to be mated. Within the series, the arrangement and size of pins will differ, to prevent accidental mating of devices with a higher current draw than the receptacle can support.
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==== NEMA 1-15 ungrounded (Type A) <span class="anchor" id="Type A"></span> ====
[[File:NEMA-1 plug polarized.agr.jpg|NEMA&nbsp;1-15 polarised plug|thumb|upright=0.9]]
[[File:A plug.jpg|NEMA&nbsp;1-15 unpolarised plug|thumb|upright=0.9]]
NEMA-1 plugs have two parallel blades and are rated 15&nbsp;A at 125&nbsp;volts. They provide no ground connection but will fit into a grounding NEMA&nbsp;5-15 receptacle. Early versions were not polarised, but most plugs are polarised today via a wider neutral blade. (Unpolarised [[AC adapter|AC&nbsp;adaptor]]s are a common exception.)

[[Harvey Hubbell]] patented a parallel blade plug in 1913, where the blades were equal width ({{US patent|1064833}}). In 1916 Hubbell received a patent for a polarised version where one blade was both longer and wider than the other ({{US patent|1180648}}), in the polarised version of NEMA&nbsp;1-15, introduced in the 1950s, both blades are the same length, only the width varies.

Ungrounded NEMA-1 outlets are not permitted in new construction in the [[United States]] and [[Canada]], but can still be found in older buildings.

==== NEMA 5-15 grounded (Type B) <span class="anchor" id="Type B"></span> ====
[[File:NEMA-AC-Power-Plugs.jpg|thumb|upright=0.9|Ungrounded vs grounded NEMA plugs]]

The NEMA&nbsp;5-15 plug has two flat parallel blades like NEMA&nbsp;1-15, and a ground (earth) pin.<ref name="NEMA">{{Citation |type =standard |url=http://www.nema.org/stds/wd6.cfm |publisher=NEMA |title=WD6, Dimensional requirements for plugs and receptacles |date=14 April 2016}}</ref> It is rated 15&nbsp;A at 125&nbsp;volts. The ground pin is longer than the live and neutral blades, such that an inserted plug connects to ground before power. The ground hole is officially D-shaped, although some round holes exist and many plugs have round ground pins. Both current-carrying blades on grounding plugs may be narrow, since the ground pin enforces polarity, but outlets have a wider opening for the neutral blade to prevent ungrounded polarized plugs from being put in backwards. This socket is recommended in IEC standard 60906-2 for 120-volt 60&nbsp;Hz installations.

The [[National Electrical Contractors Association]]'s National Electrical Installation Standards (NECA&nbsp;130-2010) recommends that sockets be mounted ''with the ground hole up'', such that an object falling on a partially inserted connector contacts the ground pin first. However, the inverted orientation (with ground pin downwards) is more commonly used. The ground-down orientation has been called the "sad socket", "dismayed face", or "shocked face" by some.<ref>''E.g.'',[https://www.gettyimages.com/photos/sad-socket Sad socket], Getty Images; accessed 2023.09.17. Ernie Smith, '[https://tedium.co/2022/08/19/unusual-electrical-socket-history/ This is my shocked face]', Tedium; accessed 2023.09.17.</ref>

Tamper-resistant sockets may be required in new residential construction, with shutters on the power blade sockets to prevent contact by objects inserted into the socket.<ref>{{Citation |url=http://www.childoutletsafety.org/ |title=Child outlet safety |access-date=21 January 2009 |archive-url=https://web.archive.org/web/20090122051010/http://www.childoutletsafety.org/ |archive-date=22 January 2009 |url-status=live}}</ref>

In [[stage lighting]], this connector is sometimes known as ''PBG'' for ''Parallel Blade with Ground'', ''Edison'' or ''Hubbell'', the name of a common manufacturer.<ref>Drew Campbell ''Technical Film and TV for Nontechnical People'', Skyhorse Publishing Inc., 2002 {{ISBN|1581159986}} Chapter&nbsp;9</ref>

==== NEMA 5-20 ====
[[File:Electrical outlet with label.jpg|thumb|upright=0.6|5-20RA (Canada) or 5-20R (US) T-slot socket mounted with the earth hole up. The neutral connection is the wider T-shaped slot on the right.]]

The NEMA 5-20&nbsp;AP variant has blades perpendicular to each other. The receptacle has a T-slot for the neutral blade which accepts either 15&nbsp;A parallel-blade plugs or 20&nbsp;A plugs.

==== NEMA 14-50 ====
[[File:NEMA 14-50 outlet.jpg|thumb|upright=0.75|NEMA&nbsp;14-50 outlet|left]]

NEMA 14-50 devices are frequently found in [[RV&nbsp;park]]s, since they are used for "[[shore power]]" connections of larger [[recreational vehicle]]s. Also, it was formerly common to connect [[mobile home]]s to utility power via a 14-50 device. Newer applications include [[Tesla, Inc.|Tesla]]'s Mobile Connector for vehicle charging, which formally recommended the installation of a 14-50 receptacle for home use.

==== Other NEMA types ====
240&nbsp;V 20-, 30- and 50-amp rated sockets are often used for high-current appliances such as air conditioners, clothes dryers and electric stoves, respectively.
{{clear}}

==== JIS C 8303, Class II unearthed<span class="anchor" id="Japan"></span> ====
<div style="width: auto; max-width: 50%; float: right; margin-left: 1em; border: 1px solid #a2a9b1;">
<gallery mode="packed" heights="200">
File:OutletPlug.jpg|Japanese Class&nbsp;II polarized sockets with earth post, for a washing machine (similar to NEMA&nbsp;1-15)
File:Japanese air conditioner electrical outlet.jpg|Japanese 20&nbsp;A socket with earth post and earth connector, for an air conditioner (similar to NEMA&nbsp;5-20)
File:Japanese air conditioner electrical outlet 200v.jpg|Japanese 200&nbsp;V socket with earth slot, for an air conditioner  (similar to NEMA&nbsp;6-20)
</gallery>
</div>

The Japanese Class II plug and socket appear physically identical to NEMA&nbsp;1-15 and also carries 15&nbsp;A. The relevant [[Japanese Industrial Standards]], JIS&nbsp;C&nbsp;8303,<ref name= JIS>{{Citation |title=JIS C 8303-1993, Plugs and Receptacles for Domestic and Similar General Use |publisher=Japanese Standards Association |year=1993}}</ref> imposes stricter dimensional requirements for the plug housing, different marking requirements, and mandatory testing and [[type approval]].

Older Japanese sockets and multi-plug adaptors are unpolarised—the slots in the sockets are the same size—and will accept only unpolarised plugs. Japanese plugs generally fit into most North American sockets without modification, but polarised North American plugs may require adaptors or replacement non-polarised plugs to connect to older Japanese sockets. In Japan the voltage is 100&nbsp;V, and the frequency is either 50&nbsp;Hz (Eastern Japan: Tokyo, Yokohama, Tohoku, Kawasaki, Sapporo, Sendai and Hokkaido) or 60&nbsp;Hz (Western Japan: Osaka, Kyoto, Nagoya, Shikoku, Kyushu and Hiroshima) depending on whether the customer is located on the Osaka or Tokyo grid.<ref>{{cite web |url=https://www.worldstandards.eu/electricity/plug-voltage-by-country/japan/ |title=Power plug, socket & mains voltage in Japan |website=WorldStandards.eu |year=2024 |access-date=6 December 2024}}</ref> Therefore, some North American devices which can be physically plugged into Japanese sockets may not function properly.

==== JIS C 8303, Class I earthed<span class="anchor" id="Japan earthed"></span> ====
Japan also uses a grounded plug similar to the North American NEMA&nbsp;5-15.<ref name=JIS/> However, it is less common than its NEMA&nbsp;1-15 equivalent. Since 2005, new Japanese homes are required to have class&nbsp;I grounded sockets for connecting domestic appliances. This rule does not apply for sockets not intended to be used for domestic appliances, but it is strongly advised to have class I sockets throughout the home.<ref>{{cite web |title=内線規程 改訂のポイントの解説ページ |url=http://www2.panasonic.biz/es/densetsu/naisen_k/wiring1.html |archive-url=https://web.archive.org/web/20120124153041/http://www2.panasonic.biz/es/densetsu/naisen_k/wiring1.html |archive-date=24 January 2012}}</ref>
{{clear}}

=== Swiss SN 441011 (Type J) ===
{{Main|SN 441011}}
[[File:J plug - 1.jpg|thumb|Type J: The 10&nbsp;ampere ''SN&nbsp;441011 type&nbsp;13'' socket (here: a triple socket) and ''type&nbsp;12'' plug]]
[[File:SEV 1011 Swiss System Plugs and Sockets.jpg|thumb|SN&nbsp;441011, overview of the hierarchical Swiss system]]

The Swiss standard, also used in [[Liechtenstein]] and [[Rwanda]]<ref name=iec_typej/> (and in other countries alongside other standards) is ''SN&nbsp;441011'' (until 2019 ''SN&nbsp;SEV&nbsp;1011) Plugs and socket-outlets for household and similar purposes''.<ref name=SEV1011>{{cite web |url=http://www.electrosuisse.ch/de/meta/shop/normen/detail.html?tx_kidsshop_product%5Bproduct%5D=122100008085493 |title=SEV 1011:2009, Plugs and socket-outlets for household and similar purposes |publisher=Electrosuisse, SEV Verband für Elektro-, Energie- und Informationstechnik |year=2009 |format=PDF |type=official site |location=Fehraltorf, Switzerland |access-date=26 May 2017 |url-access=subscription}}</ref> The standard defines a hierarchical system of plugs and sockets with two, three and five pins, and 10&nbsp;A or 16&nbsp;A ratings. Sockets will accept plugs with the same or fewer pins and the same or lower ratings.<ref name=SystemSEV1011>{{cite web |url=http://www.esti.admin.ch/en/dokumentation_electrical_products.htm |title=Information SEV 1011 – power socket/plug/connector |publisher=Federal Inspectorate for Heavy Current Installations ESTI, Swiss Confederation |date=1 August 2011 |format=PDF |type=official site |location=Fehraltorf, Switzerland |access-date=26 May 2017 |archive-url=https://web.archive.org/web/20170513140400/http://www.esti.admin.ch/en/dokumentation_electrical_products.htm |archive-date=13 May 2017 |url-status=dead}}</ref> The standard also includes three-phase devices rated at 250&nbsp;V (phase-to-neutral) / 440&nbsp;V (phase-to-phase).<ref>SN''&nbsp;''441011 dated 1 March 2022</ref> It does not require the use of child protective shutters. The standard was first described in 1959.

==== 10&nbsp;A plugs and sockets (Type J) ====
SN 441011 defines a "Type 1x" series of 10&nbsp;A plugs and sockets. The type&nbsp;11 plug is unearthed, with two 4&nbsp;mm diameter round pins spaced 19&nbsp;mm apart. The type&nbsp;12 plug adds a central 4&nbsp;mm diameter round earth pin, offset by 5&nbsp;mm. The type&nbsp;12 socket has no recess, while the type&nbsp;13 socket is recessed. Both sockets will accept type&nbsp;11 and type&nbsp;12 plugs, and also the 2.5&nbsp;A [[Europlug]]. Earlier type&nbsp;11 and 12 plugs had live and neutral pins without sleeved pins, which present a [[Electric shock|shock]] hazard when partially inserted into non-recessed sockets. The IEC type&nbsp;J designation refers to SEV&nbsp;1011's type&nbsp;12 plugs and type&nbsp;13 sockets.<ref name=iec_typej>{{cite web |url=http://www.iec.ch/worldplugs/typeJ.htm |title=Plug Type J |publisher=International Electrotechnichal Commission IEC |type=official site |location=Geneva, Switzerland |access-date=26 May 2017 |quote=Type C plugs are perfectly compatible with Type&nbsp;J sockets. |archive-date=13 March 2018 |archive-url=https://web.archive.org/web/20180313031639/http://www.iec.ch/worldplugs/typeJ.htm |url-status=dead}}</ref>

Unique to Switzerland is a three-phase power socket compatible with single-phase plugs:<ref name=SystemSEV1011/> The type&nbsp;15 plug has three round pins, of the same dimensions as type&nbsp;12, plus two smaller flat rectangular pins for two additional power phases. The type&nbsp;15 socket is recessed, and has five openings (three round and two flat rectangular). It will accept plugs of types&nbsp;11, 12, 15 and the Europlug.

==== 16&nbsp;A plugs and sockets ====
SN&nbsp;441011 also defines a "Type 2x" series of 16&nbsp;A plugs and sockets. These are the same as their 10&nbsp;A "Type 1x" counterparts, but replace the round pins with 4&nbsp;mm × 5&nbsp;mm rectangular pins. The sockets will accept "Type 1x" plugs. The unearthed type 21 plug has two rectangular pins, with centres 19&nbsp;mm apart. The type&nbsp;23 plug adds a central rectangular earth pin, offset by 5&nbsp;mm. The recessed type&nbsp;23 socket will accept plugs of types&nbsp;11, 12, 21, 23 and the Europlug.

Again, the three-phase power socket is compatible with single-phase plugs, either of 10&nbsp;A or 16&nbsp;A ratings:<ref name=SystemSEV1011/> The type&nbsp;25 plug has three rectangular pins of the same dimensions as type&nbsp;23, plus two rectangular pins of the same dimensions as type&nbsp;15. The corresponding type&nbsp;25 socket is recessed and will accept plugs of types&nbsp;11, 12, 15, 21, 23, 25 and the Europlug.

==== Regulation of adaptors and extensions ====
A 2012 appendix to SEV&nbsp;1011:2009, ''SN&nbsp;SEV&nbsp;1011:2009/A1:2012 Plugs and socket-outlets for household and similar purposes – A1: Multiway and intermediate adaptors, cord sets, cord extension sets, travel adaptors and fixed adaptors''<ref name=SEV1011A1>{{cite web |url=http://www.electrosuisse.ch/de/meta/shop/normen/detail.html?tx_kidsshop_product%5Bproduct%5D=122100008856715 |title=SEV 1011:2009/A1:2012, Plugs and socket-outlets for {{sic|houshold|nolink=y}} and similar purposes – A1: Multiway and intermediate adaptors, cord sets, cord extension sets, travel adaptors and fixed adaptors |publisher=Electrosuisse, SEV Verband für Elektro-, Energie- und Informationstechnik |year=2012 |format=PDF |location=Fehraltorf, Switzerland |access-date=26 May 2017 |url-access=subscription}}</ref> defines the requirements applicable to multiway and intermediate adaptors, cord sets, cord extension sets, and travel and fixed adaptors, it covers the electrical safety and user requirements, including the prohibition of stacking (the connection of one adaptor to another). Non-conforming products must be withdrawn from the Swiss market before the end of 2018.<ref>{{cite web |url=http://www.esti.admin.ch/files/aktuell/2013_03_stecker_steckdosen_e.pdf |title=Plugs and socket-outlets for household use and related purposes: New product requirements for the Swiss market |author=Dario Marti, Director |publisher=Federal Inspectorate for Heavy Current Installations ESTI, Swiss Confederation |date=March 2013 |type=official site |location=Fehraltorf, Switzerland |access-date=26 May 2017 |archive-url=https://web.archive.org/web/20140903134853/http://www.esti.admin.ch/files/aktuell/2013_03_stecker_steckdosen_e.pdf |archive-date=3 September 2014 |url-status=dead}}</ref>

==== Pictures ====
{|
|- valign=top
|
{| class=wikitable style=text-align:center
|+ Plug forms from SN 441011
|-
!
! Single-phase, unearthed
! Single-phase, earthed
! Three-phase, earthed
|-
! 2.5 A
| [[File:Euro-Flachstecker 2.jpg|rahmenlos|104x104px]]<br />[[Europlug]]
|
|
|-
! 10 A
| [[File:SN 441011 Typ 11 L+N Stecker.png|rahmenlos|104x104px]]<br />Type 11
| [[File:SEV 1011 2009 Typ 12 L+N+PE Stecker.jpg|rahmenlos|104x104px]]<br />Type 12
| [[File:SEV 1011 Type 15 plug.jpg|rahmenlos|104x104px]]<br />Type 15
|-
! 16 A
| Type 21
| [[File:SEV 1011 Type 23 plug.jpg|rahmenlos|104x104px]]<br />Type 23
| [[File:SEV 1011 Type 25 plug.jpg|rahmenlos|104x104px]]<br />Type 25
|}
|
{| class="wikitable style"="text-align:center"
|+ Socket forms from SN 441011
|-
!
! Single-phase, earthed
! Three-phase, earthed
|-
! 10 A
| [[File:SEV 1011 Typ 13 Steckdose einfach.jpg|rahmenlos|140x140px]]<br />Type 13
| [[File:SEV 1011 Typ 15 Steckdose.jpg|rahmenlos|140x140px]]<br />Type 15
|-
! 16 A
| [[File:SEV 1011 single Type 23 wall socket.jpg|rahmenlos|140x140px]]<br />Type 23
| [[File:SEV 1011 Typ 25 Steckdose.jpg|rahmenlos|140x140px]]<br />Type 25
|}
|
<gallery center mode=packed heights=140 caption="Other Swiss socket forms">
SEV 1011 Typ 12 Steckdose.jpg|Type 12 triple socket (10&nbsp;A), now obsolete and no longer sold or installed
SEV 1011 Typ 14 Stecker.jpg|Type 14 single socket (10&nbsp;A), now obsolete
SEV 1011 Typ 13 Steckdose.jpg|Type 13 triple socket (10&nbsp;A)
SEV 1011 Typ 23 Steckdose.jpg|Type 23 triple socket (16&nbsp;A)
</gallery>
|}
{{clear}}
{{anchor|Thai Industrial Standard 166-2549}}

=== Thai plug TIS 166-2549 (Type O) ===
[[File:Thai TIS 166-2549 mains plug.jpg|thumb|TIS&nbsp;166-2549 plug (grounded variant)]]

Thai Industrial Standard (TIS)&nbsp;166-2547 and its subsequent update TIS&nbsp;166-2549<ref>{{cite web |title=TIS 166-2549 (2006) (English): Plugs and socket-outlets for household and similar purposes: plugs and socket-outlets with rated voltage not exceeding 250&nbsp;V |url=https://law.resource.org/pub/th/ibr/th.cs.166.e.2549.pdf |url-status=dead |archive-url=https://web.archive.org/web/20160707011303/https://law.resource.org/pub/th/ibr/th.cs.166.e.2549.pdf |archive-date=7 July 2016}}</ref> replaced prior standards which were based on NEMA&nbsp;1-15 and 5-15, as Thailand uses 220&nbsp;V electricity. The plug has two round power pins 4.8&nbsp;mm in diameter and 19&nbsp;mm in length, insulated for 10&nbsp;mm and spaced 19&nbsp;mm apart, with an earthing pin of the same diameter and 21.4&nbsp;mm in length, located 11.89&nbsp;mm from the line connecting the two power pins. The earth pin spacing corresponds to that of NEMA&nbsp;5 and provides compatibility with prior hybrid three-pin sockets, which accept NEMA&nbsp;1-15, NEMA&nbsp;5-15, and [[Europlug]]s, all of which have been variably used in Thailand.

The standard also defines an ungrounded plug with a smaller form factor that is very similar to the Europlug (but a bit higher); its power pins are identical to the grounded variant and both are rated for up to 16&nbsp;A (while the Europlug is only rated for 2.5&nbsp;A). The generally used hybrid socket is also defined in TIS&nbsp;166-2547, in addition to a plain three-round-pin socket, with plans to eventually replace the former and phase out support for NEMA-compatible plugs. Sockets are polarised (as in NEMA&nbsp;5-15).<ref>{{cite book |title=Thai Industrial Standard 166-2547: Plugs and socket-outlets for household and similar purposes: plugs and socket-outlets with rated voltage not exceeding 250&nbsp;V |publisher=Thai Industrial Standards Institute |isbn=974-9815-94-7 |location=TH |url=http://app.tisi.go.th/notices/pdf/TIS166-2549.pdf |access-date=23 November 2011 |language=th |url-status=dead |archive-url=https://web.archive.org/web/20120426001040/http://app.tisi.go.th/notices/pdf/TIS166-2549.pdf |archive-date=26 April 2012}}</ref>

The grounded plug is similar to, but not interchangeable with, the Israeli SI32 plug. The Thai plug is designated as "Type&nbsp;O" at IEC World Plugs.<ref name="World Plugs"/><ref name=WorldSTDs>{{cite web |url=https://www.worldstandards.eu/electricity/plugs-and-sockets/o/ |title=Power plug & outlet Type O |website=WorldStandards.eu |date=27 December 2024 |access-date=18 February 2025}}</ref><ref name=Bombay>{{cite web |url=https://www.bombayelectronics.com/products/orei-thailand-travel-plug-adapter-2-usa-inputs-3-pack-type-o |title=OREI Thailand Travel Plug Adapter – 2 USA Inputs – 3 Pack – Type O |website=BombayElectronics.com |access-date=29 May 2018}}</ref><ref name=PPS>{{cite web |url=https://www.power-plugs-sockets.com/ |title=Check your need for a travel adapter! |website=Power-Plugs-Sockets.com |access-date=2 June 2018}}</ref><ref name=IntConfigs>{{cite web |url=http://internationalconfigurations.com/thai-power-cords-power-supply-cords.php |title=Thai – Power Cords |website=InternationalConfigurations.com |access-date=2 June 2018}}</ref><ref name=GearPatrol>{{cite web |url=https://gearpatrol.com/2015/02/06/guide-to-plugs-and-sockets-by-country/ |title=Every International Outlet, in One Handy Chart |website=GearPatrol.com |date=6 February 2015 |access-date=2 June 2018}}</ref>
{{clear}}

=== Special purpose plugs and sockets ===
[[File:20061007_3P_N_PE_CEE_connections.jpg|thumb|400&nbsp;V CEE sockets with cables plugged in.]]

Special purpose sockets may be found in residential, industrial, commercial or institutional buildings. Examples of systems using special purpose sockets include:
* "Clean" (low electrical noise) earth for use with computer systems,
* [[Device for Connection of Luminaires]] (DCL) is a European standard for ceiling- and hanging light fixtures.
* [[Emergency power system|Emergency power supply]],
* [[Uninterruptible power supply]] for critical or life-support equipment,
* Isolated power for medical instruments, tools used in wet conditions, or electric razors,
* [[Split-phase electric power#Balanced power|"Balanced" or "technical"]] power used in audio and video production studios,
* [[Stage lighting|Theatrical lighting]],
* [[IEC 60309|CEE 17]] are a series of industrial grade (IP44) three-phase "pin & sleeve" connectors for industrial purposes, carpentry- and gardening appliances and also used as a weather-resistant connector for outdoor usage, like [[Caravan (trailer)|Caravans]], [[Motorhome]]s, [[campervan]]s and [[tent]]s for mains hook-up at [[Campsite|camp-site]]s.<ref>[https://www.campingandcaravanningclub.co.uk/helpandadvice/technicalhelp/datasheets/electricity-campers-caravanners/ Using electricity on a campsite] [[Camping and Caravanning Club]]</ref><ref>[https://www.campingandcaravanningclub.co.uk/travelabroad/camping-in-europe/european-campsites/electricity/ Electricity on European Campsites] [[Camping and Caravanning Club]] (UK, so "European" means mainland Europe)</ref>
* Sockets for electric clothes dryers, electric ovens, and air conditioners with higher current rating.

Special-purpose sockets may be labelled or coloured to identify a reserved use of a system, or may have keys or specially shaped pins to prevent use of unintended equipment.

==== Single-phase electric stove plugs and sockets ====
[[File:Power connector Legrand 32A.jpg|thumb|Plug (sheet V) and socket (sheet VI) to French standard NF&nbsp;C&nbsp;61-315 (400&nbsp;V, 32&nbsp;A)]]

The plugs and sockets used to power [[electric stove]]s from a single-phase line have to be rated for greater current values than those used with three-phase supply because all the power has to be transferred through two contacts, not three. If not hardwired to the supply, electric stoves may be connected to the mains with an appropriate high power connector. Some countries do not have wiring regulations for single-phase electric stoves. In Russia, an electric stove can often be seen connected with a 25 or 32&nbsp;A connector.

In Norway, a 25[[AC power plugs and sockets: British and related types#BS 4573 (UK shaver)|&nbsp;]]A grounded connector, rectangular shaped with rounded corners, is used for single-phase stoves.{{Citation needed|date=June 2024}} The connector has three rectangular pins in a row, with the grounding pin longer than other two. The corresponding socket is recessed to prevent shocks. The Norwegian standard is NEK&nbsp;502:2005 – standard sheet X (socket) and sheet XI (plug). They are also known as the two pole and earth variants of CEE&nbsp;7/10 (socket) and CEE&nbsp;7/11 (plug).

{{Multiple image |align=center |direction=horizontal |footer=Russian stove connectors rated 250&nbsp;V 25&nbsp;A AC. Left: plug and socket. Center: Socket. Right: Plug. |image1=Russian stove plug and socket.jpg |width1=150 |image2=Russian stove outlet.jpg |width2=175 |image3=Russian stove plug.jpg |width3=200}}
{{anchor|shaver}}

==== Shaver supply units ====
[[File:ShaverSocketUK.jpg|thumb|upright=0.6|Shaver supply unit for BS&nbsp;4573, US&nbsp;Type&nbsp;A, Australian two-pin, and Europlug Type&nbsp;C]]

National wiring regulations sometimes prohibit the use of sockets adjacent to water taps, etc. A special socket, with an [[isolation transformer]], may allow electric razors to be used near a sink. Because the isolation transformer is of low rating, such outlets are not suitable to operate higher-powered appliances such as [[hair dryer]]s.

An IEC standard 61558-2-5, adopted by [[European Committee for Electrotechnical Standardization|CENELEC]] and as a national standard in some countries, describes one type of shaver supply unit. Shaver sockets may accept multiple two-pin plug types including Australian (Type&nbsp;I) and [[AC power plugs and sockets: British and related types#BS 4573 (UK_shaver)|BS&nbsp;4573]]. The isolation transformer often includes a 115&nbsp;V output accepting two-pin US plugs (Type&nbsp;A). Shaver supply units must also be current limited, IEC 61558-2-5 specifies a minimum rating of 20&nbsp;[[Volt-ampere|VA]] and maximum of 50&nbsp;VA.<ref>IEC&nbsp;61558-2-5</ref> Sockets are marked with a shaver symbol, and may also say "shavers only".

Isolation transformers and dedicated NEMA&nbsp;1-15 shaver receptacles were once standard installation practice in North America, but now a [[Residual-current device|GFCI]] receptacle is used instead. This provides the full capacity of a standard receptacle but protects the user of a razor or other appliance from leakage current.

Differences between BS4573 Type&nbsp;C and Europlug Type&nbsp;C. The BS4573 plug has round 5mm contacts, spacing 16mm. The Euro-plug has 4mm contacts, spacing 19mm. In order to plug a Europlug into a BS4573 socket, an adaptor is required.

== Comparison of standard types ==
{{sticky header}}
{| class="wikitable sortable sticky-header"
! [[International Electrotechnical Commission|IEC]]<br />TR<br />60083<br />World<br />Plugs<br />Type{{efn|name=worldplugs|Type letters are from the International Electrotechnical Commission ([[International Electrotechnical Commission|IEC]]) Web site<ref name="World Plugs"/> that provides classification letters similar to a United States Department of Commerce publication<ref name=ECO/> that sees widespread but not universal use to differentiate plug and socket types based on rough mechanical compatibility. Most common household plugs have an associated letter.}}
! Standard
! Origin
! colspan="2" | Rating
! Earthed (groun&shy;ded)
! Polarised
! Fused
! Insulated pins
! Socket accepts Europlug
|-
! rowspan="3" | A
| [[NEMA connector#NEMA 1|NEMA]][[AC power plugs and sockets: British and related types#BS 4573 (UK shaver)|&nbsp;]]1-15
| American and Canadian
| 15&nbsp;A
| 125&nbsp;V
| {{No}}
| {{maybe|Optional}}{{efn|name=nema-polarised|Polarised plugs have a wider neutral blade; sockets accept both polarised and unpolarised plugs.}}
| {{No}}
| {{No}}
| {{No}}
|-
| JIS&nbsp;C&nbsp;8303, Class&nbsp;II & CNS&nbsp;10917-1, CNS&nbsp;10917-2
| Japanese and Taiwanese
| 15&nbsp;A
| 100&nbsp;V
| {{No}}
| {{maybe|Optional}}{{efn|name=nema-polarised}}
| {{No}}
| {{No}}
| {{No}}
|-
| GB&nbsp;1002
| Chinese
| 10&nbsp;A
| 250&nbsp;V
| {{No}}
| {{No}}
| {{No}}
| {{No}}
| {{No}}
|-
! rowspan="2" | B
| [[NEMA connector#NEMA 5|NEMA]][[AC power plugs and sockets: British and related types#BS 4573 (UK shaver)|&nbsp;]]5-15
| American and Canadian
| 15&nbsp;A
| 125&nbsp;V
| {{Yes}}{{efn|name=typebcomp|Will accept unearthed plugs.}}
| {{Yes}}
| {{No}}
| {{No}}
| {{No}}
|-
| JIS&nbsp;C&nbsp;8303, Class&nbsp;I & CNS&nbsp;10917-3
| Japanese and Taiwanese
| 15&nbsp;A
| 100&nbsp;V
| {{Yes}}{{efn|name=typebcomp}}
| {{Yes}}
| {{No}}
| {{No}}
| {{No}}
|-
! C
| [[Europlug|CEE]][[AC power plugs and sockets: British and related types#BS 4573 (UK shaver)|&nbsp;]]7/16
| Europlug
| 2.5&nbsp;A
| 250&nbsp;V
| {{No}}
| {{No}}
| {{No}}
| {{Yes}}
| {{n/a}}{{efn|name=europlugNA|Standard does not define a socket.}}
|-
| {{n/a}}
| [[CEE 7 standard AC plugs and sockets#CEE 7/17 unearthed plug|CEE]][[AC power plugs and sockets: British and related types#BS 4573 (UK shaver)|&nbsp;]]7/17 plug{{efn|name=hybrid17|CEE 7/17 specifies an unearthed hybrid plug that fits into both the CEE&nbsp;7/3 and CEE&nbsp;7/5 sockets.}}
| French / German ''hybrid''
| 16&nbsp;A
| 250&nbsp;V
| {{No}}
| {{No}}{{efn|There are some CEE 7/17 plugs with special shape which are polarised when used with CEE&nbsp;7/5 sockets (mechanically only).}}
| {{No}}
| {{No}}{{efn|name=human}}
| {{N/A}}{{efn|name=europlugNA}}
|-
| {{n/a}}
| [[CEE 7 standard AC plugs and sockets#CEE 7/1 unearthed socket and CEE 7/2 unearthed plug|CEE]][[AC power plugs and sockets: British and related types#BS 4573 (UK shaver)|&nbsp;]]7/1 socket & CEE&nbsp;7/2 plug
| European
| 16&nbsp;A<br />10&nbsp;A
| 250&nbsp;V
| {{No}}{{efn|CEE 7/1 socket accepts earthed CEE&nbsp;7/3, CEE&nbsp;7/5 and CEE&nbsp;7/7 plugs but provides no earth connection.}}
| {{No}}
| {{No}}
| {{No}}
| {{Yes}}
|-
| rowspan="2" {{n/a}}
| rowspan="2" | [[AC power plugs and sockets: British and related types#BS 4573 (UK shaver)|BS&nbsp;4573]]
| rowspan="2" | British
| 0.2&nbsp;A
| 250&nbsp;V
| rowspan="2" {{No}}
| rowspan="2" {{No}}
| rowspan="2" {{No}}
| rowspan="2" {{Yes}}
| rowspan="2" {{No}}
|-
| colspan="2" | Socket only; plug is unspecified{{efn|BS 4573 and BS EN 61558-2-5 do not explicitly specify a current rating for a compliant plug, see BS&nbsp;4573 section of British and compatible standards.}}
|-
! rowspan="3" | D
| [[AC power plugs and sockets: British and related types#BS 546|BS]][[AC power plugs and sockets: British and related types#BS 4573 (UK shaver)|&nbsp;]]546 || British
| 5&nbsp;A
| 250&nbsp;V
| {{Yes}}
| {{Yes}}
| {{optional}}
| {{optional}}
| {{No}}
|-
| IS&nbsp;1293
| Indian
| 6&nbsp;A
| 250&nbsp;V
| {{Yes}}
| {{Yes}}
| {{optional}}
| {{optional}}
| {{No}}
|-
| [[SANS 164#SANS 164-3|SANS]][[AC power plugs and sockets: British and related types#BS 4573 (UK shaver)|&nbsp;]]164-3
| South African
| 6&nbsp;A
| 250&nbsp;V
| {{Yes}}
| {{Yes}}
| {{optional}}
| {{optional}}
| {{No}}
|-
! E
| [[CEE 7 standard AC plugs and sockets#CEE 7/5 socket and CEE 7/6 plug (French; Type E)|CEE]][[AC power plugs and sockets: British and related types#BS 4573 (UK shaver)|&nbsp;]]7/5 socket & CEE&nbsp;7/6 plug{{efn|name=hybrid7}}{{efn|name=hybrid17}}
| French
| 16&nbsp;A
| 250&nbsp;V
| {{Yes}}{{efn|name=typebcomp}}
| {{maybe|Partially}}{{efn|Plug can only be inserted one way with French CEE&nbsp;7/5, but lack of wiring convention means that the system is not polarised.}}
| {{No}}
| {{No}}{{efn|name=human|The recess provided by CEE 7/3 and CEE 7/5 sockets offers protection against touching the live pins of CEE 7/4, CEE 7/6, CEE 7/7, and CEE 7/17 plugs. When used in CEE 7/1 (unearthed) sockets or "universal adaptors" there is no protection for those plugs.}}
| {{Yes}}
|-
! F
| [[CEE 7 standard AC plugs and sockets#CEE 7/3 socket and CEE 7/4 plug (German "Schuko"; Type F)|CEE]][[AC power plugs and sockets: British and related types#BS 4573 (UK shaver)|&nbsp;]]7/3 socket & CEE&nbsp;7/4 plug{{efn|name=hybrid7}}{{efn|name=hybrid17}}
| German "[[Schuko]]"
| 16&nbsp;A
| 250&nbsp;V
| {{Yes}}{{efn|name=typebcomp}}
| {{No}}
| {{No}}
| {{No}}{{efn|name=human}}
| {{Yes}}
|-
| {{n/a}}
| [[CEE 7 standard AC plugs and sockets#CEE 7/7 plug (compatible with E and F)|CEE]][[AC power plugs and sockets: British and related types#BS 4573 (UK shaver)|&nbsp;]]7/7 plug{{efn|name=hybrid7|CEE 7/7 specifies an earthed hybrid plug that fits into both the CEE&nbsp;7/3 and CEE&nbsp;7/5 sockets.}}
| French / German ''hybrid''
| 16&nbsp;A
| 250&nbsp;V
| {{Yes}}
| {{No}}{{efn|Not polarised when used with a CEE&nbsp;7/3 socket, most CEE&nbsp;7/7 plugs are (mechanically only) polarised when used with a CEE&nbsp;7/5 socket}}
| {{No}}
| {{No}}{{efn|name=human}}
| {{n/a}}{{efn|name=europlugNA}}
|-
! G
| [[AC power plugs and sockets: British and related types#BS 1363 three-pin (rectangular) plugs and sockets|BS]][[AC power plugs and sockets: British and related types#BS 4573 (UK shaver)|&nbsp;]]1363, IS&nbsp;401 & IS&nbsp;411, MS&nbsp;589, SS&nbsp;145
| British
| 13&nbsp;A{{efn|The actual rating of non-rewirable plugs is marked according to the fuse fitted by the cord set manufacturer, the fuse rating being determined by the rating of the flexible cable.}}
| 250&nbsp;V
| {{Yes}}{{efn|Also accepts unearthed Class&nbsp;II plugs that include an unwired dummy earth pin.}}
| {{Yes}}
| {{Yes}}
| {{Yes}}
| {{No}}
|-
! H
| SI&nbsp;32
| Israeli
| 16&nbsp;A
| 250&nbsp;V
| {{Yes}}{{efn|name=typebcomp}}
| {{Yes}}{{efn|name=except-unearthed-plugs|Except when used with unearthed plugs such as the Europlug.}}
| {{No}}
| {{No}}
| {{Yes}}
|-
! rowspan="3" | I
| [[AS/NZS 3112|AS/NZS]][[AC power plugs and sockets: British and related types#BS 4573 (UK shaver)|&nbsp;]]3112
| Australian and New Zealand
| 10&nbsp;A<br />15&nbsp;A<br />20&nbsp;A
| 250&nbsp;V
| {{Yes}}{{efn|name=typebcomp}}
| {{Yes}}
| {{No}}
| {{Yes}}
| {{No}}
|-
| GB&nbsp;1002 ''and'' GB&nbsp;2099.1
| Chinese
| 10&nbsp;A<br />16&nbsp;A
| 250&nbsp;V
| {{Yes}}{{efn|The 16&nbsp;A socket also accepts unearthed Class&nbsp;II plugs that include an unwired dummy earth pin.}}
| {{Yes}}
| {{No}}
| {{optional}}{{efn|Will become mandatory in 2027.}}
| {{No}}
|-
| IRAM&nbsp;2073
| Argentine
| 10&nbsp;A<br />20&nbsp;A
| 250&nbsp;V
| {{Yes}}{{efn|name=typebcomp}}
| {{Yes}}
| {{No}}
| {{optional}}
| {{No}}
|-
! J
| [[SN 441011|SN]][[AC power plugs and sockets: British and related types#BS 4573 (UK shaver)|&nbsp;]]441011 (formerly SN&nbsp;SEV&nbsp;1011)<br />Type 12 plug and Type 13 receptacle
| Swiss
| 10&nbsp;A
| 250&nbsp;V
| {{Yes}}{{efn|name=typebcomp}}
| {{Yes}}{{efn|name=except-unearthed-plugs}}
| {{No}}
| {{Yes}}{{efn|Import of plugs with non-partially-insulated pins no longer allowed after 2012.}}
| {{Yes}}
|-
! K
| 107-2-D1
| Danish
| 16&nbsp;A
| 250&nbsp;V
| {{Yes}}{{efn|name=typebcomp}}
| {{Yes}}{{efn|name=except-unearthed-plugs}}
| {{No}}
| {{No}}{{efn|The recess provided by Danish sockets offers protection against touching the live pins of plugs.}}
| {{Yes}}
|-
! rowspan="2" | L{{efn|name=typel|Type L comes in two variations with ratings of 10&nbsp;A and 16&nbsp;A having different pin diameters and spacing from each other.}}
| CEI&nbsp;23-50 (formerly CEI&nbsp;23-16)
| Italian
| 10&nbsp;A
| 250&nbsp;V
| {{Yes}}{{efn|name=typebcomp}}
| {{No}}
| {{No}}
| {{Yes}}
| {{Yes}}
|-
| CEI&nbsp;23-50 (formerly CEI&nbsp;23-16)
| Italian
| 16&nbsp;A
| 250&nbsp;V
| {{Yes}}{{efn|name=typebcomp}}
| {{No}}
| {{No}}
| {{Yes}}
| {{No}}
|-
! rowspan="3" | M
| [[AC power plugs and sockets: British and related types#BS 546|BS]][[AC power plugs and sockets: British and related types#BS 4573 (UK shaver)|&nbsp;]]546
| British
| 15&nbsp;A
| 250&nbsp;V
| {{Yes}}
| {{Yes}}
| {{optional}}
| {{optional}}
| {{No}}
|-
| IS&nbsp;1293:2005
| Indian
| 16&nbsp;A
| 250&nbsp;V
| {{Yes}}
| {{Yes}}
| {{optional}}
| {{optional}}
| {{No}}
|-
| [[SANS 164#SANS 164-1|SANS]][[AC power plugs and sockets: British and related types#BS 4573 (UK shaver)|&nbsp;]]164-1
| South African
| 16&nbsp;A
| 250&nbsp;V
| {{Yes}}
| {{Yes}}
| {{optional}}
| {{optional}}
| {{No}}
|-
! rowspan="4" | N
| [[IEC 60906-1#Brazilian NBR 14136 standard|NBR]][[AC power plugs and sockets: British and related types#BS 4573 (UK shaver)|&nbsp;]]14136 two-pin
| Brazilian
| 20&nbsp;A<br />10&nbsp;A
| 250&nbsp;V
| {{No}}
| {{No}}
| {{No}}
| {{Yes}}
| {{n/a}}{{efn|name=europlugNA}}
|-
| NBR&nbsp;14136 three-pin
| Brazilian
| 20&nbsp;A<br />10&nbsp;A
| 250&nbsp;V
| {{Yes}}{{efn|name=typebcomp}}
| {{Yes}}{{efn|name=except-unearthed-plugs}}
| {{No}}
| {{Yes}}
| {{Yes}}
|-
| [[SANS 164#SANS 164-2|SANS]][[AC power plugs and sockets: British and related types#BS 4573 (UK shaver)|&nbsp;]]164-2 two-pin{{efn|name=PNA-IEC 60906-1|Also used in Paraguay (PNA-IEC 60906-1).<ref name=PNA-IEC-60906-1/>}}
| South African
| 16&nbsp;A
| 250&nbsp;V
| {{No}}
| {{No}}
| {{No}}
| {{Yes}}
| {{n/a}}{{efn|name=europlugNA}}
|-
| SANS&nbsp;164-2 three-pin{{efn|name=PNA-IEC 60906-1}}
| South African
| 16&nbsp;A
| 250&nbsp;V
| {{Yes}}{{efn|name=typebcomp}}
| {{Yes}}{{efn|name=except-unearthed-plugs}}
| {{No}}
| {{Yes}}
| {{Yes}}
|-
! rowspan="2" | O
| TIS&nbsp;166-2549 two-pin
| Thai
| 16&nbsp;A
| 250&nbsp;V
| {{No}}
| {{No}}
| {{No}}
| {{Yes}}
| {{n/a}}{{efn|name=europlugNA}}
|-
| TIS&nbsp;166-2549 three-pin
| Thai
| 16&nbsp;A
| 250&nbsp;V
| {{Yes}}{{efn|name=typebcomp}}
| {{Yes}}{{efn|name=except-unearthed-plugs}}
| {{No}}
| {{Yes}}
| {{Yes}}
|-
! [[International Electrotechnical Commission|IEC]] World Plugs Type{{efn|name=worldplugs}}
! Standard
! Origin
! colspan="2" | Rating
! Earthed
! Polarised
! Fused
! Insulated pins
! Socket accepts Europlug
|}

{{notelist}}

== Unusual types ==
{{For|obsolete types|History of AC power plugs and sockets#Obsolete types}}

=== Lampholder plug ===
<div style="width: auto; max-width: 50%; float: right; margin-left: 1em; border: 1px solid #a2a9b1;">
<gallery mode="packed" heights="120">
File:Lampholder plugs.jpg|Italian bypass lampholder plugs with Edison screw mount.<br />Left: early type (porcelain and brass, c. 1930).<br />Right: late type (black plastic, c. 1970)
File:Lampholder plug adapter.jpg|Lampholder plug (US, c. 1950–1960)
</gallery>
</div>

A lampholder plug fits into a light socket in place of a [[Electric light|light bulb]] to connect appliances to lighting circuits. Where a lower rate was applied to electric power used for lighting circuits, lampholder plugs enabled the consumers to reduce their electricity costs.<ref>{{cite web |url=https://www.worldstandards.eu/electricity/history/why-no-universal-plug/ |title=Why isn't there a universal standard electric plug? |website=WorldStandards.eu |access-date=13 December 2024}}</ref> Lampholder plugs are rarely fused. Edison screw lampholder adaptors (for NEMA&nbsp;1-15 plugs) are still commonly used in the Americas.
{{clear}}

=== Soviet standard GOST 7396 C&nbsp;1 unearthed ===
<div style="width: auto; max-width: 50%; float: right; margin-left: 1em; border: 1px solid #a2a9b1;">
<gallery mode="packed" heights="200">
File:Soviet Plug Type1 6A 250V.jpg|Soviet grip plug, 6&nbsp;A 250&nbsp;V AC, thermoset plastic
File:Soviet Plug Type2 6A 250V.jpg|Soviet round plug, 6&nbsp;A 250&nbsp;V AC, thermoset plastic, half height
File:Soviet moulded rubber plugs 6A 250V cut.jpg|Moulded rubber Soviet plugs cut with knife so that they can fit into CEE&nbsp;7/3 socket. Originally the plugs had a round base.
File:Soviet shaver power cord.jpg|Soviet shaver power cord. The plug is similar to CEE&nbsp;7/16, but has different configuration. Thermoplastic plug is rated 6&nbsp;A and 250&nbsp;V.
</gallery>
</div>

{{further|GOST 7396#Group C}}

This Soviet plug, now rarely used, has pin dimensions and spacing equal to the Europlug, but lacks the insulation sleeves. Unlike the Europlug, it is rated 6&nbsp;A. It has a round body like the European CEE&nbsp;7/2 or flat body with a round base like CEE&nbsp;7/17. The round base has no notches. The pins are parallel and do not converge. The body is made of fire-resistant [[Thermosetting polymer|thermoset plastic]]. The corresponding 6&nbsp;A socket accepts the Europlug, but not others as the 4.5&nbsp;mm holes are too small to accept the 4.8&nbsp;mm pins of CEE&nbsp;7/4, CEE&nbsp;7/6 or CEE&nbsp;7/7 plugs.

There were also moulded rubber plugs available for devices up to 16&nbsp;A similar to CEE&nbsp;7/17, but with a round base without any notches. They could be altered to fit a CEE&nbsp;7/5 or CEE&nbsp;7/3 socket by cutting notches with a sharp knife.
{{clear}}

=== Soviet adaptor plugs ===
[[File:Soviet power plug.JPG|thumb|Soviet adaptor plug]]

Some appliances sold in the Soviet Union had a flat unearthed plug with an additional pass-through socket on the top, allowing a stacked arrangement of plugs. The usual Soviet apartment of the 1960s had very few sockets, so this design was very useful, but somewhat unsafe; the brass cylinders of the secondary socket were uncovered at the ends (to allow them to be unscrewed easily), recessed by only 3&nbsp;mm, and provided bad contact because they relied on the secondary plug's bisected expanding pins. The pins of the secondary plug (which lacked insulation sleeves) could not be inserted into the cylindrical sockets completely, leaving a 5&nbsp;mm gap between the primary and secondary plugs. The adaptors were mostly used for low power appliances (for example, connecting both a table lamp and a radio to a socket).

{{anchor|Walsall|walsall}}

=== UK Walsall Gauge plug ===
[[File:WG13 PICT6943.jpg|thumb|upright=0.85|Walsall Gauge 13&nbsp;A plug (bottom) compared to regular BS&nbsp;1363 plug]]

Unlike the standard BS&nbsp;1363 plugs found in the UK, the earth pin is on a horizontal axis and the live and neutral pins on a vertical axis. This style of plug/socket was used by university laboratories (from batteries) and the [[BBC]], and is still in use in parts of the [[London Underground]] for 110&nbsp;V{{spaces}}AC voltage supply.<ref>{{cite web |url=http://www.plugsocketmuseum.nl/British2.html |title=Non-standard BS 1363 types |work=Museum of Plugs and Sockets |access-date=3 November 2019}}</ref> In the 1960s they were used for 240&nbsp;V&nbsp;DC in the Power laboratory of the Electrical Engineering department of what was then [[Cardiff University|University College, Cardiff]]. Power was supplied by the public 240&nbsp;V&nbsp;DC mains which remained available in addition to the 240&nbsp;V&nbsp;AC mains until circa 1969, and thereafter from in-house rectifiers. They were also used in the [[Ministry of Defence Main Building]] inside circuits powered from the standby generators to stop staff from plugging in unauthorized devices. They were also known to be used in some [[British Rail]] offices for the same reason.
{{clear}}

=== Italian BTicino brand Magic Security connector ===
<div style="width: auto; max-width: 50%; float: right; margin-left: 1em; border: 1px solid #a2a9b1;">
<gallery mode="packed" heights="120">
File:Bticino Magic 1.jpg|Magic Security socket, detail.
File:Bticino Magic 2.jpg|Assortment of Magic Security sockets (in orange, the industrial three-phase type)
File:Bticino Magic 3.jpg|Assortment of Magic Security plugs
File:Spina magic 02.jpg|Magic Security plug (10&nbsp;A) (left) with a type L to Magic Security plug adaptor
</gallery>
</div>

In the 1960s, the Italian firm [[Bticino|BTicino]] introduced an alternative to the Europlug or CEI&nbsp;23-16 connectors then in use, called Magic Security.{{sfn|De Cesco|1975|p=73}} The socket is rectangular, with lateral key pins and indentations to maintain polarisation, and to prevent insertion of a plug with different current ratings. Three single-phase general purpose connectors were rated 10&nbsp;A, 16&nbsp;A and 20&nbsp;A; and a three-phase industrial connector rated 10&nbsp;A; all of them have different key-pin positioning so plugs and sockets cannot be mismatched.{{sfn|De Cesco|1975|p=75}} The socket is closed by a safety lid (bearing the word ''Magic'' on it) which can be opened only with an even pressure on its surface, thus preventing the insertion of objects (except the plug itself) inside the socket. The contacts are positioned on both sides of the plug; the plug is energised only when it is inserted fully into the socket.

The system is not compatible with Italian CEI plugs, nor with Europlugs. Appliances were never sold fitted with these security plugs, and the use of adaptors would defeat the safety features, so the supplied plugs had to be cut off and replaced with the security connector. Even so, the ''Magic'' security system had some success at first because its enhanced safety features appealed to customers; standard connectors of the day were not considered safe enough.{{sfn|De Cesco|1975|p=73}} The decline of the system occurred when safety lids similar to the Magic type were developed<ref>{{cite web |url=http://www.vimar.eu/index.php?l=it&module=articles&class=articles&event=__default&menu_item_id=134&content=20 |title=La ricerca della sicurezza. Il brevetto Sicury |website=www.vimar.eu. |access-date=12 February 2009}}</ref> for standard sockets.

In Italy, the system was never definitively abandoned. Though very rarely seen today, it is still marked as available in BTicino's catalogue,<ref>{{cite web |url=https://bticino.assetbank-server.com/bticino/assetfile/50782.pdf |archive-url=https://web.archive.org/web/20210224161322/https://bticino.assetbank-server.com/bticino/assetfile/50782.pdf |url-status=dead |archive-date=24 February 2021 |website=bticino.assetbank-server.com |title=Il Classico Dell'Installazione Civile |access-date=20 May 2017}}</ref> (except for the three-phase version, which stopped being produced in July 2011).

In Chile, 10&nbsp;A Magic connectors are commonly used for computer/laboratory power networks, as well as for communications or data equipment. This allows delicate electronics equipment to be connected to an independent circuit breaker, usually including a [[surge protector]] or an [[uninterruptible power supply]] backup. The different style of plug makes it more difficult for office workers to connect computer equipment to a standard unprotected power line, or to overload the UPS by connecting other office appliances.

In Iceland, Magic plugs were widely used in homes and businesses alongside Europlug and Schuko installations. Their installation in new homes was still quite common even in the late 1980s.

== See also ==
{{Portal|Electronics}}
{{div col|colwidth=23em}}
* [[Anderson Powerpole]]
* [[DC connector]]
* [[History of AC power plugs and sockets]]
* [[IEC 60309]] high-power industrial and polyphase connectors
* [[IEC 60320|IEC 60320 Appliance couplers for household and similar general purposes]]
* [[Industrial and multiphase power plugs and sockets]]
* [[Mains electricity]]
* [[Mains electricity by country]] lists voltage, frequency, and connector types for over 200 countries
* [[Perilex]] 
* [[Pattress]]
* [[Plug load]]
* [[Polyphase system]]
* [[Smart plug]]
* [[Stage pin connector]]
* [[Light switch]]
{{div col end}}

== References ==
{{reflist}}

== External links ==
{{Commons category}}
{{Wikibooks|Guide to electrical equipment for travellers}}
* [http://www.plugsocketmuseum.nl/ Digital Museum of Plugs and Sockets] (comprehensive collection of plugs and sockets)
* [http://www.electropedia.org Glossary of standards terms]
* [https://www.gewinde-normen.de/en/e-thread.html Edison thread]

{{Electronic components}}
{{Authority control}}

[[Category:Electrical standards]]
[[Category:Electrical wiring]]
[[Category:Mains power connectors]]