What are the types of electrical outlets?

Today, there are numerous types of sockets that are used everywhere and are used for plug-in connection of electricity consumers to the network.

Despite the apparent simplicity of these devices, they perform a number of very responsible functions, the main of which include:

1. Ensuring reliable contact between the plug of the appliance and the socket of the household power supply at an allowable current.
2. Protection against accidental or intentional touching of live parts with your hands or foreign objects. It is especially important to provide such protection in rooms where small children have access to outlets.
3. Ensuring reliable isolation of live parts from each other and from the housing of the appliance.
4. Elimination of the possibility of improper connection of the consumer to the network (polarized plug). This property is especially relevant for electrical appliances that use single-pole circuit breakers.
5. Connection protective earth. This function is assigned to most models of modern outlets, which, in addition to the contacts for the 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, however, in most Soviet-built apartment buildings, a ground wire is missing.
6. Protection from connecting devices that are not rated for its voltage to the electrical network (the so-called "protection against the fool").
7. Ensuring fire safety in case of emergency in the operation of electrical wiring.

In addition, the housing material and the method of installing the electrical outlet must maximize the overall design of the room and the personal preferences of the landlord.

The large number of requirements of various nature that are presented to these devices force manufacturers to offer an extremely wide range of models on the market. Today, in electrical goods stores and construction supermarkets, you can find the most modern sockets for various functional purposes and appearance. In such conditions, it can be difficult to decide on the optimal model for the 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 the working part is the same for them, and the decorative linings can be easily replaced with those that more suit the tastes of users. In addition, modular sockets can be used for compact placement of connectors that are used for connecting various devices: household electrical appliances, television antennas, landlines and 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 the electric plug are inserted, as well as contacts with screw or key type terminals for connecting 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 material of the body 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 a few times 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 plug pins. This ensures their tight connection and reliable electrical contact.

Outlet Classification

Since state standards of different countries provide for various parameters of the electrical network and requirements for the installation of electrical installations, it is quite natural that there a large number of various electrical outlets, the differences of which consist in the value of their rated voltage and current, the number of pins, overall dimensions, polarization methods and etc.

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 outlets that are used in such electrical networks.

According to the international classification, sockets that can be used in our country belong to two types:

1. Type F or CEE 7/4 "Schuko" with grounding (according to GOST 7396.1-89 refers to type C2).
2. Type C without grounding. (according to GOST 7396.1-89 refers to type C1-a).

The following types of outlets are distinguished

• By the method of attaching to the wall: for use in open or hidden wiring. In a separate group, portable sockets can be distinguished.

Distinguish between 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 just 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 you need to quickly replace faulty or establish a new point for connecting electrical appliances to the network, and carry out significant repairs in terms of volume impractical.

The advantages of the built-in models of sockets include their more attractive than that of invoices analogues, appearance, as well as reliability of fastening and a high degree of protection against damage electric shock. Such protection is achieved by the fact that all live parts are located deep in the wall, the decorative part is practically not protrudes beyond its borders, which reliably protects the device from various, including unintentional, mechanical impacts.

• The magnitude of the current.

Almost all modern electrical outlets are designed for currents of 6, 10 and 16 A. This is much more than the performance of old Soviet models, the rated current of which was 6.3 A.

For connecting particularly powerful consumers, such as hobs, air conditioners or boilers, special devices should be used that are highly resistant to large currents. In addition, all of them without fail have a contact for connecting protective earth. However, such equipment is usually installed permanently and cannot be moved around the apartment. Therefore, in many cases, outlets are not used at all to increase the reliability of electrical connections when connecting powerful consumers. The wire through which the power is supplied to the appliance is displayed directly on the electrical panel when entering the apartment and connected to it through a separate circuit breaker corresponding power.

In order to determine the allowable power of the consumer, which can be connected to the mains via an outlet, it is necessary to multiply the values ​​of the maximum current and voltage.

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 occurs, firstly, due to the appearance of an additional detachable connection, and secondly, due to the poor quality of contacts of most tees and extension cords.

• By the presence of protective grounding. There are sockets with a contact for connecting the ground wire, as well as those that do not have this contact.

Grounding models are undoubtedly safer if you can properly connect such a device. Otherwise, there is no difference between the two species. And if the ground wire is connected incorrectly, then the risk of electric shock increases many times.

In old apartment buildings, electrical wiring provides for only two wires: neutral and phase. The zero wire is connected to the neutral point of the three-phase electric 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 through the neutral wire of the three-phase system does not flow and the voltage on it relative to the earth is to zero.

In the event of accidents (severe phase imbalance, open circuit or short circuit), situations may arise when a certain potential appears in relation to earth on the neutral wire.

If the case of an electric appliance, for example, a washing machine, is “grounded” to the neutral wire through an outlet, 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 wired wire, however, in high-rise buildings, this is quite difficult to accomplish.

Additional accessories and functions of electrical outlets

To provide higher reliability, protection in conditions of negative environmental impact or simply to create ease of use, some types of sockets are equipped with additional accessories or a set functions.

Childproof

They include special shutters that close electrical contacts and can only be removed by connecting wires with a standard plug to the outlet.

With protection against dust or high humidity

They are equipped with special covers that reliably protect contacts from environmental influences during the period when the device is not in use. Secure Outlets Designed for installation on the street or in rooms with high humidity, for example, in bathrooms.

Backlit

Special LED beacons are built into the case of such devices, which make it easy to find a place to connect the appliance to 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 night light.

With switch

Quite an exotic option, in our country it is not widespread. The switch on such a socket serves to reliably isolate the consumer from the electrical network without removing the plug from the connector. This creates additional convenience in the operation of electrical appliances and significantly increases the service life of the outlet, which It is designed for a certain number of connections and disconnections of the plug from it (as a rule, from 3 to 5 thousand cycles).

With integrated residual current device

Such devices can become extremely useful if it is not possible to properly ground the body of a powerful electric consumer, for example, a washing machine. As a matter of fact, there are two main types of protection against electric shock: protective grounding and protective shutdown. The essence of the first is that when the phase is closed to the body of the appliance, the current along the path of least resistance goes into the ground through a wire specially designed for this purpose. Residual current device installed in the socket, triggered when a leakage current occurs due to insulation damage, as well as when a short circuit occurs.

With timer

Application such devices allows you not to think about whether all consumers are disconnected from the network. The timer will automatically instruct the automation to shut off after a set time.

Thus, if you do not pay attention to the numerous types of electrical outlets that are intended for use in power systems of foreign countries, then choosing the right device for installation in your apartment is not so complicated.

The first and main requirement is the compliance of the maximum allowable current of the power outlet of the consumers connected to it, as well as the quality of all the elements that are included in its design. If these properties satisfy the necessary requirements, it is worth paying attention to the operating conditions of the device: the presence of a large amount of dust or moisture (at installing it in a bathroom, on the street or in a repair shop), the availability of the outlet for children and, finally, its appearance, as well as matching the interior premises.