The huge variety of outlets currently being produced is due to the multitasking of these elements of the electrical network. The specific conditions for their application dictate certain requirements for not only their appearance, but also functional parameters. This article describes in detail as much as possible all types of sockets that exist today, having studied the features of which you will receive comprehensive information regarding the design differences and principles of operation of devices designed for plug connections.
Depending on the country in which certain standards are enshrined in law, sockets differ in the number of contact elements, as well as their shapes and sizes. Moreover, each device has a letter designation, approved at the end of the last century by the US Department of Commerce. The classification proposed by the Americans has been approved by other countries, and is currently valid worldwide:
A - a standard that at one time was ubiquitous throughout North America. Following the United States, it began to be used in 38 countries. This type consists of two ungrounded flat contacts arranged in parallel. A grounding element is not provided in this case. Today, such devices can still be seen in many old buildings, as they are all compatible with the modern type of plugs. Certain differences are the Japanese standard, which provides additional requirements for the parameters of the cases of products.
B - An improved version of the American standard, supplemented at the bottom of the design with a long round contact that provides grounding. In addition to the United States, these types of electrical outlets are used in Canada and Mexico. In addition, they are found in several countries in South America, including Colombia, Ecuador and Venezuela.
C - The most common standard in Europe. The so-called Euro socket, consisting of two round contacts, is used, including in the CIS, as well as in the Middle East and in most countries of the African continent. There is no grounding in this design. In the Russian Federation, the dimensions and safety requirements for such products are determined by GOST 7396.
D - An outdated standard previously applied by the British in the territories belonging to the British Empire. At the moment, sockets with three round contacts located on the tops of the triangle are mainly used in India, and are also found in old houses in other countries, where the British had a hand in arranging power lines.
E - The modern French standard, which differs from type C by the presence of a grounding contact, which is located at the top of the device. Similar power supply elements are also used in Belgium and Poland. At one time they were introduced on the territory of the former Czechoslovakia.
F - European standard in the form of a design of two round contacts, supplemented with grounding brackets at the top and bottom. Initially, such devices appeared in Germany and began to be used for alternating current.These types of sockets and plugs are also called “Schuko”, which is short for German Schutzkontakt, which literally means “protective contact”. Products are completely compatible with forks of the Russian and Soviet production.
G - The British standard, providing for the presence of a fuse inside the plug. The device consists of three flat contacts, two of which are located at the bottom, and one at the top. It is allowed to connect euro plugs by means of a special adapter, in which a fuse must also be integrated. This type of power supply is supported in Ireland, as well as in some states that were once British colonies.
H - The Israeli standard, which consists of three round contacts (flat elements were used until 1989), forming the Latin letter Y in their arrangement. This type of connection to the electric network is unique because it is used exclusively in Israel. Other types of sockets and plugs are completely incompatible with it.
I - A standard common in Australia and New Zealand. Two flat contacts are installed at an angle. The third is vertically located below and is the grounding element. Similar types of electrical outlets are used in Papua New Guinea, as well as in the Republic of the Fiji Islands.
J - The Swiss standard, which has a certain similarity with type C, but characterized by the presence of an earthing contact, laid aside. When connecting euro plugs, there is no need to use adapters.
TO - Danish standard, the only difference from the French type is the location of the grounding contact installed directly in the plug, and not in the design of the outlet.
L - The Italian standard, assuming compatibility with Europlugs of type C. The design consists of three round contacts forming a horizontal row.
In some cases, old British designs still in use in South Africa may be marked with the letter M.
According to European standards, voltage indicators in the mains are usually 220-240 or 380V. Sockets designed for 220 volts are usually used to connect various electrical appliances whose power does not exceed 3.5 kW. This limitation is due to the inability of standard devices designed for low-power household appliances to cope with currents that go beyond 16A.
For more powerful electrical appliances, it is recommended to use industrial three-phase sockets, for which the permissible current is 32A. Such products are designed for a voltage of 380V.
In addition, for different types of outlets, a certain frequency of alternating current is provided, the indicators of which are 50 or 60 Hz. The most common European standard, including those used in Russia, is designed for the first option.
According to the installation method, electrical outlets can be divided into three main categories. The housing variant in this case depends on the type of wiring.
Embedded products involve the installation of a block on which the contacts are located in a special box (socket box) hidden in the wall. As a result, only the protective case of the device, slightly protruding above the surface, is within sight. For power networks with grounding, sockets are used that are equipped with additional grounding contacts.
In cases with external wiring, overhead structures are installed that are fixed to the wall surface. Contact elements are located under the product body, completely hiding the connector.
There are quite original types of overhead type electrical outlets, the installation of which consists in securing the device to the baseboard that hides the wiring laid under it. In Russia, they are not particularly popular because they do not harmonize with modern interiors at all, and also often break as a result of mechanical influences.
Portable sockets are often equipped with a cord with a plug, which allows you to use them as extension cords. However, there are also models without a cord that connect directly to the cable that is led out of the wall. During installation, it is necessary to divide the device into two parts, loosening the construction screws, then strip the contacts and insert them into the clamping terminals. Some portable products are equipped with a power button and an indicator that displays the operating mode.
The device, which provides for the presence of two electrical points, allows you to simultaneously connect different devices to the network. The basis of such a product is a block made in accordance with standard sizes, so that installation of an additional socket is not required. Structurally, the differences in the types of outlet blocks consist solely in the number of seats. The internal space of the case is divided into terminals, in each of which contacts and terminals are located.
In cases with open wiring, it is recommended to use an overhead block for mounting a socket block designed for three power consumers.
For a closed electrical wiring, a frame with the appropriate number of sections is used. In each section, you can insert a socket, the result is a block consisting of three sockets.
To install four or more points in most cases, single-socket devices connected to a single system are used. For installation, a frame with the appropriate number of sections is used.
There are models of sockets in which, in addition to the main components, special electronic or mechanical components are installed, which are assigned certain functions. Different types of electrical outlets may have certain features, which we will consider later.
Sockets with built-in RCD
Designs with built-in RCDs are designed to connect powerful electrical appliances. Mostly they are installed in bathrooms, since with an increased level of humidity in the room, the risk of electric shock increases. Thanks to the residual current circuit breaker, a built-in relay is triggered at the moment of leakage, timely opening the input contacts. This allows not only to prevent damage to the appliance, but also to prevent harm to human health.
Sockets with curtains
Models with curtains, which in everyday life are often called "childproof outlets", are equipped with special panels that hide the input jacks. Access to the contacts in this case is possible only at the moment the plug enters the holes. In fact, the task of the curtains is to prevent any foreign objects from getting into the outlet. This is ideal for a children's room.
Sockets with covers
Sockets with covers are mainly used in rooms with high humidity. At the same time, the protective elements prevent not only the ingress of water, but also dust inside the device. Additional mechanisms are attached using special grips and screws.
The model with a timer allows the user to independently set the time period after which the power supply to the device will be stopped. These types of sockets are quite convenient to use when operating heaters that are not equipped with their own automatic shutdown system.
Sockets with electric meter
Designs equipped with a built-in electricity meter make it possible to control the consumption of energy by one or another household appliance. The indicator on the case changes color based on the power of the connected device.
A model with a plug ejector is an excellent option for those whose socket is not firmly fixed in the socket. The presence of an additional mechanism allows you to most accurately pull out the plug, without putting much effort.
Illuminated power outlet designed for use in low visibility conditions. It allows even in complete darkness to quickly find a place where you need to connect a particular electrical device.
Sockets with USB output
Products equipped with a USB output. These are modern models of sockets, with the help of which at any time you can recharge your mobile phone, camera or other device.
An electrical outlet with a built-in WiFi module allows you to control the devices used in the house using a smartphone or tablet. Inside such a device is located a distance-controlled microprocessor that is responsible for supplying electricity.
There are sockets designed for strictly defined purposes and structurally different from conventional devices. These include:
Walk-through socketswhich are intermediate elements in the electrical circuit. In this case, a power wire is connected to the contacts, which does not end there, but is sent to the next device. These types of electrical outlets are used, as a rule, with the error-free method of breeding wiring.
Shield rosettedesigned for use in distribution panels and installed using special metal strips equipped with snap mechanisms.
Antenna socketequipped with a special connector compatible with the cable end of the television antenna.
An outlet for connecting to the Internet, which can also provide the connection of several computers interacting with each other. It differs from other types of devices in the number of contacts and the structure of the cable lug socket.
The degree of protection of various types of sockets against contact, as well as the ingress of certain parts of solids, particles of dust and moisture, is indicated by the IP marking, where the first digit corresponds to the following indicators:
- 0 - complete lack of protective functions with open access to equipment nodes;
- 1 - limited penetration of large solids with dimensions greater than 5 cm. Protection against finger touch is not expected;
- 2 - protection is provided for the fingers, and also the hit of an object from 1.25 cm in size is excluded;
- 3 - the components of the device are protected from possible contact with power tools and other foreign objects, the size of which exceeds 2.5 mm;
- 4 - indicates the presence of protection against the ingress of solid particles having sizes greater than 1 mm;
- 5 - indicates partial protection against dust;
- 6 - The highest degree of protection against ingress of any foreign objects, including microscopic dust particles.
The second digit of the marking indicates the degree of protection of the device from moisture. "0" in this case also indicates the absolute insecurity of the equipment nodes. Other notation can be seen in the following examples:
- 1 - vertically falling drops on contact with the shell will not cause a circuit;
- 2 - drops that have fallen vertically at an angle of no more than 15 degrees will not be able to overcome the shell;
- 3 - protection prevents circuiting even in cases when drops of water fall at an angle of 60 degrees;
- 4 - the components of the equipment are reliably protected from moisture, regardless of the direction of movement of the spray;
- 5 - it is allowed to hit a water jet that is not under pressure. Devices with a similar designation can be washed regularly;
- 6 - the equipment is capable of withstanding sufficiently powerful directed water flows;
- 7 - short-term immersion of the device in water to a depth of not more than 1 meter is allowed;
- 8 - allowed diving to a significant depth;
- 9 - absolute tightness allows the equipment to function under water with unlimited duration.
The NEMA mark is used for types of electrical outlets manufactured in the USA that have been certified. Below are the areas of use for devices with various NEMA indicators:
- 1 - products are intended for installation in domestic and administrative buildings and provide protection against ingress of dirt;
- 2 - designed for domestic premises, where there is a probability of moisture in minimal quantities;
- 3 - devices used outside buildings in conditions of increased dust formation, as well as atmospheric precipitation. The “3R” and “3S” models have additional characteristics;
- 4 and 4X - equipment capable of withstanding dirt sprayed as a result of vehicle traffic, and also resistant to aggressive weather conditions;
- 6 and 6P - protective functions are provided by a sealed enclosure, due to which the device can be under water at a relatively shallow depth;
- 11 - products are mainly used in places where corrosion processes constantly occur;
- 12 and 12K - designed for rooms with a high level of dust formation;
- 13 - They are especially resistant to various types of pollution, including oily substances.
There are also other types of markings, which, for example, indicate the degree of strength of the body of the product. However, it does not make sense to consider this indicator in relation to a conventional household outlet.