Today, there are numerous types of sockets that are used everywhere and serve to plug-in the connection of electricity consumers to the network.
Despite the apparent simplicity of these devices, they perform a number of very important functions, the main of which include:
- Ensuring reliable contact between the plug of the electrical appliance and the socket of the household power supply at the permissible current.
- Protection against accidental or intentional contact with current-carrying parts by hands or foreign objects. It is especially important to provide such protection in rooms where small children have access to sockets.
- Ensuring reliable isolation of current-carrying parts from each other and from the body of the electrical appliance.
- Elimination of the possibility of incorrect connection of the consumer to the network (polarized plug). This property is especially relevant for those electrical appliances that use single-pole switches.
- Connection protective earth. This function is assigned to most models of modern sockets, which, in addition to contacts for neutral and phase wires, also have a contact to which the ground loop is connected. This, of course, provides additional protection for people from electric shock, but in most Soviet-era apartment buildings there is no ground wire.
- Protection against connecting to the electrical network of devices that are not designed for its voltage (the so-called "fool protection").
- Ensuring fire safety in case of emergency situations in the operation of electrical wiring.
In addition, the material of the case and the method of installing the electrical outlet should be as close as possible to the overall design of the room and the personal preferences of the owner of the apartment.
A large number of requirements of a different nature that apply to these devices force manufacturers to offer an extremely wide range of their models on the market. Today, in electrical stores and building supermarkets, you can find the most modern sockets for various functional purposes and appearance. In such conditions, it can be quite difficult to decide on the choice of the optimal model in terms of price and quality. To simplify this task as much as possible, it is necessary, at least in general terms, to imagine the features of the design and classification of modern electrical outlets.
The design of electrical outlets
Almost all modern models of these devices are made on a modular basis. This means that they have the same working part, and decorative overlays can be easily replaced with those that are more in line with the tastes of users. In addition, modular sockets can be used to compactly accommodate sockets that are used to connect various devices: household appliances, TV antenna, landline phone, etc.
The main elements of any plug connection are electrical contacts, the reliability and duration of operation of the device depend on the material and quality of their manufacture. In any outlet there are two types of contacts: sockets into which the pins of an electrical plug are inserted, as well as contacts with screw or key-type terminals designed to connect household electrical wires.
For the manufacture of decorative external parts, special plastics are used, which are distinguished by high electrical insulating properties, incombustibility and aesthetic appeal.
The body material of the working part is high-strength plastic.Domestic manufacturers still produce sockets with a ceramic working part, which has not been done in Western Europe for a long time. Porcelain is a very fragile material, so you should think twice before buying such a device for your apartment.
To ensure the highest quality electrical connection, the receiving sockets are equipped with spring-loaded contacts, the diameter of which is smaller than the diameter of each of the pins of the plug. This ensures their tight connection and reliable electrical contact.
Socket Classification
Since the state standards of different countries provide for different parameters of the electrical network and requirements for electrical installations, it is quite natural that there are a large number of very different electrical outlets, the differences of which are in the value of their rated voltage and current, the number of pins, overall dimensions, polarization methods, etc. d.
In our country, as well as in many European and Asian countries, electricity is used with a voltage of 230 V and a frequency of 50 Hz. Therefore, it makes sense to consider only those sockets that are used in such electrical networks.
According to the international classification, sockets that can be used in our country belong to two types:
- Type F or CEE 7/4 "Schuko" with grounding (according to GOST 7396.1-89 refers to type C2).
- Type C without grounding. (according to GOST 7396.1-89 refers to type C1-a).
There are the following types of sockets
- According to the method of fastening to the wall: for use in wiring of an open or hidden type. In a separate group, portable sockets can be distinguished.
There are overhead and built-in (flat) sockets. As a rule, overhead models are used when installing open wiring. Their main advantage is the extreme ease of installation. In order to install such a device, there is no need to drill a hole for the socket, but it is enough just to fix the block on the wall with two screws. In wooden houses, this installation option is almost the only one, since it fully complies with the requirements of fire safety rules.
Overhead sockets can also be used as temporary devices in cases where it is necessary to quickly replace a faulty one or install a new connection point for electrical appliances to the network, and it is impractical to perform significant repairs in terms of volume.
The advantages of the built-in models of sockets include their more attractive appearance than their overhead counterparts, as well as the reliability of fastening and a high degree of protection against electric shock. Such protection is achieved by the fact that all current-carrying parts are located deep in the wall, the decorative part practically does not protrude beyond its limits, which reliably protects the device from various, including unintentional, mechanical influences.
- By the amount of current.
Almost all modern electrical outlets are designed for currents of 6, 10 and 16 A. This is significantly more than the performance of old Soviet models, the rated current of which was 6.3 A.
To connect particularly powerful consumers, such as hobs, air conditioners or boilers, special devices should be used that are characterized by increased resistance to high currents. In addition, all of them without fail have a contact for connecting a protective earth. However, such equipment, as a rule, is installed permanently and cannot be moved around the apartment. Therefore, in many cases, sockets are not used at all to increase the reliability of electrical connections when connecting powerful consumers.The wire through which the electrical appliance is powered is output directly to the electrical panel when entering the apartment and is connected to it through a separate circuit breaker of the appropriate power.
In order to determine the permissible power of a consumer that can be connected to the mains through a socket, it is necessary to multiply the values \u200b\u200bof the maximum current and voltage of the network.
In this way:
P = U*Imax = 220*10 = 2200 W, or P = U*Imax = 220*16 = 3520 W.
It should be noted here that when using most models of splitters, the total allowable power of electrical appliances connected to the outlet is significantly reduced. This happens, firstly, due to the appearance of an additional detachable connection, and secondly, due to the poor quality of the contacts of most tees and extension cords.
- By the presence of protective grounding. There are sockets that have in their composition a contact for connecting a ground wire, as well as those that do not have this contact.
Grounded models are undoubtedly safer if it is possible to properly connect such a device. Otherwise, there is no difference between the two types. And if the ground wire is connected incorrectly, then the risk of electric shock increases many times over.
In old apartment buildings, electrical wiring provides for only two wires: zero and phase. The neutral wire is connected to the neutral point of a three-phase electrical network, the phases of which are connected according to the "star" scheme (only such a connection is used to power residential buildings). In addition, the neutral wire must be properly grounded. Under normal operating conditions (that is, if there are no accidents in the network and the load on each phase is approximately the same), the current does not flow through the neutral wire of the three-phase system and the voltage on it relative to ground is zero.
In the event of accidents (strong phase imbalance, open circuit or short circuit), situations may arise when a certain potential appears on the neutral wire with respect to ground.
If the body of an electrical appliance, for example, a washing machine, is “grounded” to a neutral wire through a socket, then there is a risk of electric shock to people. To prevent this phenomenon, it is best to make a separate grounding with a specially brought out wire, but in high-rise buildings this is quite difficult to do.
Additional accessories and functions of electrical outlets
For greater reliability, environmental protection, or simply for ease of use, some types of outlets are equipped with additional accessories or a set of functions.
With child protection
They include special shutters that cover electrical contacts and can only be removed when connected to a wire socket with a standard plug.
Protected against dust or moisture
They are equipped with special covers that reliably protect the contacts from environmental influences during the period when the device is not in use. Protected sockets designed for installation outdoors or in rooms with high humidity, such as bathrooms.
backlit
Special LED beacons are built into the case of such devices, which make it easy to find a place to connect an electrical appliance in the dark, in addition, the lights of these LEDs make it easier to navigate in a dark room and can create additional comfort instead of a night light.
With switch
Quite an exotic option, in our country it is not common. The switch on such a socket serves to reliably isolate the consumer from the electrical network without removing the plug from the socket.This creates additional convenience in the operation of electrical appliances and significantly increases the service life of the outlet, which is designed for a certain number of plugs and plugs disconnected from it (usually from 3 to 5 thousand cycles).
With built-in residual current device
Such devices can become extremely useful if it is not possible to properly ground the case of a powerful electrical consumer, for example, a washing machine. Strictly speaking, there are two main types of protection against electric shock: protective earthing and protective shutdown. The essence of the first is that when the phase is closed to the body of the electrical appliance, the current along the path of least resistance goes into the ground through a wire specially designed for this. Residual current device installed in the socket, is triggered when a leakage current appears due to damage to the insulation, as well as in the event of a short circuit.
With timer
Application such devices allows you not to think about whether all consumers are disconnected from the network. The timer will automatically command the automation to turn off after the set time has elapsed.
Thus, if you do not pay attention to the numerous types of electrical outlets that are designed for use in the power supply systems of foreign countries, then choosing the right device for installation in your apartment is not so difficult.
The first and main requirement is the compliance of the maximum permissible current of the socket with the power of the consumers connected to it, as well as the quality of all the elements that are included in its design. If these properties meet the necessary requirements, you should pay attention to the operating conditions of the device: the presence of a large amount of dust or moisture (when installing it in a bathroom, on the street or in a repair shop), the accessibility of the socket for children and, finally, its appearance, and also matching the interior of the room.
