Install a double outlet instead of a single one. Parallel and serial connection of sockets

The cable is used the same as the main wiring in the room. The materials must also be the same. If the connection is made with an aluminum wire, it is also used when connecting sockets.

Use of the device requires caution. The total load on this type of socket should not exceed 10-16 A.

Installation steps - do everything in order

The double socket connection diagram consists of the following steps:

This completes the installation work. If the quality of the installation is in doubt, contact a professional electrician. He will inspect your work and make sure that the operation will not lead to electric shock.

Video on how to install a double socket

Few people managed to avoid the problem of a lack of sockets in the apartment. This is especially true for houses built back in the days of the USSR, where the number of sockets in a room, the height and location of their installation were determined by some rules unknown to anyone from “secret manuscripts”, devoid of engineering justification and common sense. As a result, residents received sockets, as if specially hidden behind cabinets and sofas, and a "web" of additional extension cords, stretching to the right places under sofas and carpets.

Although such measures were then the only salvation, they did not add security, since an electric fireplace, iron, hair dryer and other powerful consumers of electrical energy could be "plugged" into one extension cord at the same time. And it’s very good if it worked in the shield, but this did not always happen. A real "saving straw" in such a situation can be a double socket, which is installed instead of a single socket in the same mounting box. In the article, we will consider in what cases these devices can be installed, what varieties of them exist, and we will analyze in detail the installation process itself.

There are never too many outlets: The Plus One Rule

Any experienced electrician knows that there are no many outlets! And they are absolutely right, because with any even the most correct design of electrical wiring and its installation, there still comes a moment when somewhere there will not be enough sockets. Therefore, when planning, you need to use one good rule called “plus one”. That is, where, according to all norms and preliminary estimates, one outlet is needed, two should be boldly installed. Where there are two, there are boldly 3 and so on. On kitchen aprons, at the location of audio and video equipment, near all desks, you should safely install a block of three sockets plus a computer one, and where there is a TV, then also an antenna.

Some top-class electricians, whose service queue has been measured for years, install at least 3 blocks of 4 sockets in any living room, and in the right places, and not behind the planned furniture. At the installation stage, this results in higher costs, but then decades of comfortable life follow without extension cords, which are always a source of increased danger. An exception to the “plus one” rule are only dedicated lines intended only for specific consumers: washing machines and dishwashers, instantaneous electric heaters, electric stoves, air conditioners, security systems (alarm and video surveillance). To such consumers, a separate one from the shield is laid, and sockets are sometimes highlighted in a different color, for example, red, emphasizing their “special status”.

Is a double socket a necessary measure?

Answering this question, we say a firm "Yes"! A double socket is really a necessary measure. It is much better to have two separate outlets combined under a common frame than one double. Let's try to justify this statement.

The mechanisms of modern sockets and switches are mounted in standard mounting boxes with a diameter of 68 mm and a depth of 40 mm or 60 mm (increased depth). The latter are used so that switching elements can also be placed behind the mechanism, which allows you to get rid of junction boxes. Mounting boxes are also often referred to as socket boxes. Such a definition is erroneous, but it has become so commonplace that it is useless to fight it.

The boxes are made of plastic, on the side surfaces and at the back there are perforated holes for cable entry, which are easily cut out with a knife in the right place. On the side of the boxes there may be "ears" - protrusions that can be used to connect the boxes together. Inside the "ears" in the future it is easy to lay the wire. Boxes connected by "ears" have standard center-to-center distances of 71 mm. This allows you to mount the mechanisms of sockets, switches, dimmers and other devices nearby.

And then close them with a single frame in two places. If each outlet was mounted with its own frame, then the mounting boxes would have to be “pushed apart” to a greater distance and there would be a gap between them, which is not so aesthetically pleasing.

Now it is worth defining some concepts. Sockets in which two separate mechanisms are mounted in their mounting boxes, and then they are combined under one frame are called double or a block of two outlets. Consider what is double power socket. Its main difference is that two contact groups for two sockets are mounted in one mechanism located in one. The composition of the mechanism can be seen in the following figure.

The main part of the socket mechanism is the housing (1), which is made of heat-resistant plastic. Earlier it was possible to meet ceramic cases, however, now it is either rare or very expensive. A support (2) is attached to the body, which is "responsible" for the exact positioning of the socket on a flat wall surface and fastening the mechanism to the mounting box using self-tapping screws (10).

The electrical part of the socket consists of a rail (3), which is two brass plates folded together and connected, which fit into the grooves of the body. At the ends of the busbar, the plates "diverge" forming spade contacts (4), which are responsible for reliable contact with the cylindrical pins of the plug (plug). Although brass is an elastic material, the connection can still become loose over time, breaking contact. To prevent this phenomenon, spring clips (5) are installed in good sockets. Contact with the wire is provided by a square nut (6), pressing it against the busbar with a screw (7). The stripped wire starts from the back of the case through special holes.

Fastening and centering of the socket mechanism in the mounting box, in addition to self-tapping screws (10), is carried out by two spring-loaded tabs (8), which have sharp ends. When screws 9 are rotated clockwise (twisting), the locking tabs move apart and abut against the relief inner surface of the mounting box, securely fixing the mechanism.

Prices for double sockets

double socket

We examined the mechanism of a double socket without a ground contact. Now let's see how she looks with him.

In contrast to the previous example, it can be seen that bent ground contacts (1) have appeared, connected to the protective zero wire (PE) using a terminal, which is clamped with a screw (2). This socket compares favorably with the fact that the screws of all terminals - both phase and zero working, and grounding (2, 3) are on the front side, which will allow tightening without removing the mechanism from the mounting box. Another undoubted advantage of this sample is that the busbars are closed with a plastic cover (4). The front cover (5), which performs a protective and decorative function, is attached to the mechanism with two (and not one, as in the previous example) screws. Any specialist will note the quality of this outlet, which once again confirms the excellent reputation of the French company Schneider Electric.

The weak point of dual sockets is the placement of a mechanism that "serves" two sockets in one back box, although this may be noted by some as an advantage. Let us now justify our assertion.

• In order to “accept” two plug connectors at the same time, the spade contacts have to be moved as far as possible - to the very edge of the mechanism, where they will be dangerously close to the mounting box, which is made of ordinary, not heat-resistant plastic. If a powerful load is plugged into the outlet, the contacts will get very hot and can “soften” the plastic of the mounting box.
• There are two electrical connections in the limited space of the mounting box, and if both of them are loaded, then in such "crowding" they will have little chance of cooling. Therefore, you should never plug two powerful loads into one double outlet. Double sockets are much more "willing" to overheat and fail.

• A double 16 Amp socket is capable of passing such a current from two consumers in total, and in a block of two sockets, each of them is capable of passing a current of 16 Amperes.
• Due to the fact that two single sockets must fit in the mechanism of a double socket, designers have to give up the best in favor of a simpler one.
• Due to the design features, a built-in double outlet protrudes from the wall much more than a single one. The presented drawing shows that the double one protrudes by 26.5 mm, while the single one (including those combined into a block) - by 12 mm. This difference is visible to the naked eye. Double sockets look less aesthetically pleasing, and a block of sockets and other devices, united by a frame for 2-5 posts, looks like a single ensemble and does not spoil the interior. Rather, they even decorate it. In addition, a double socket protruding strongly from the wall is more likely to be damaged.

• In a double socket, it may be difficult to connect two angled plugs, which are equipped with many different devices. If the double socket is mounted horizontally, the holes will be oriented vertically, so the wire coming from the angled plug will go sideways, breaking as it does so. If the double socket is mounted vertically, then the situation will not improve much: the lower plug will be connected normally, and on the top the wire will go up, and then break down 180 °.

If a double socket has such a set of disadvantages, then the question arises - why, in general, are they produced and installed? Let's imagine a situation where a certain family lives in an apartment in which the electrician was made back in the days of the USSR, which automatically means a catastrophic shortage of sockets. To make major repairs with a complete replacement of electrical wiring, the family simply does not have money, but they save it. If you replace all the sockets in the apartment and put double ones instead of single ones, then you can partially get rid of the “outlet hunger”, eliminate the tees and remove most of the extension cords. These measures will greatly improve security. And in this case, double sockets are a real salvation.

Double sockets are a head taller than tees and extension cords, but lose in all respects to socket blocks. The only advantage is that one double outlet is cheaper than two single ones combined in a block (double).

How to choose a good double socket

In order to choose the right double socket, you should find out what varieties there are. Let's briefly consider this issue and immediately comment on in which case it is worth using one or another option.

In Russia, the countries of the former USSR and in most European countries, two main connector standards are used:

• connector type C . In such sockets there is no grounding contact, the holes are at a distance of 19 mm. plugs can have pins with a diameter of 4 or 4.8 mm and a length of 19 mm. this connector is designed to connect those electrical appliances that do not require grounding, such as a hair dryer, electric shaver, vacuum cleaner, hand blender and others. For these devices, the plug also does not have a grounding contact. Such sockets in our country are also called "Soviet", although in the USSR there were slightly different standards. Nevertheless, after increasing the diameter of the holes in the lid with a drill or a file, most European plugs were “accepted” by Soviet sockets.

Prices for double earthed sockets

double earthed sockets

• connector type F . This standard is also called Schuko (Shuko), it was developed in Germany and is widely used in Europe. We know it as sockets with grounding or "Euro sockets". The type F connector differs from the type C connector in that in sockets, in addition to phase and zero, there are curved brackets connected to the ground wire. On the plug there are flat metal contacts of the protective zero, which, when inserted into the socket, are connected to the brackets earlier. All complex household appliances sold in Russia and requiring grounding of the case are equipped with type F plugs. Sockets of this standard can also “accept” all standard C plugs.

If you plan to install a double socket in an apartment or house where there is a grounding system, then you should definitely choose the F standard, and if not, then the C standard. However, an important note must be made - some household appliances must be connected to a grounded socket. What then to be when there is simply no third wire in the outlet? In this case, a separate three-wire cable is run from the access shield under the protection of its machine of the appropriate rating. In the apartment for such devices, sockets with grounding are installed. The cable is temporarily run openly in a cable channel, and then during a major overhaul, everything is done “wisely” - hidden wiring is laid with grounding.

Some "craftsmen" install a socket with grounding and make a jumper in it between the working zero and the protective zero (grounding). This is a gross violation and life-threatening!

According to the installation method, sockets can be:

• Built-in sockets - those that are mounted with hidden wiring in the mounting box.
• Overhead sockets - mounted on the surface of the walls with open wiring.

In some situations, it is very beneficial to install a surface-mounted outlet, as some models have two separate mechanisms assembled in one housing. This means that all those disadvantages of double sockets that we talked about above will not concern them.

According to the degree of protection IP (protection of the shell of the device), double, and any other, sockets used in everyday life can be:

• IP22 - this means that objects with a diameter of more than 12.5 mm (fingers) cannot penetrate the socket and vertically dripping water should not interfere with the operation of the device. This degree of protection is sufficient for residential premises, but if there are children in the house, then it is recommended to choose products with a more “serious” IP.
• Sockets with degrees of protection IP33 and IP43 already have protective shutters that prevent various objects from 2.5 mm in diameter (IP33) and 1 mm (IP43) from penetrating inside. That is, inquisitive children will not be able to put a finger, a screwdriver, a wire, or even their mother's hairpin into the socket. These devices are also protected from the effects of vertical or “oblique” splashes, but it is better not to use them in bathrooms and baths.

Prices for double sockets "Legrand"

double sockets "Legrand"

• IP44 - these sockets can be installed in bathrooms. They have protective covers with rubber gaskets and are not afraid of splashes from any direction. But this does not mean at all that such sockets can be safely watered from the shower.

• IP55 - sockets with such protection can be safely placed on the street, as they are not afraid of dust, splashes, or even water jets. For household sockets, IP55 is the highest protection.

What else should I pay attention to when choosing a double socket model? The main rule when choosing is not blind faith in the words of the seller, but a personal inspection of the mechanism.

• Sockets for 220 V are produced for currents of 10 A or 16 A. And although it is not a fact that at least 10 A current will flow through any socket, you still need to make a choice in favor of 16 A models. A margin of safety never hurts.
• Some models of double sockets attract inexperienced buyers with a low price. And when “opening” it turns out that there is no support in these sockets or it is primitive in the form of two “lugs”. Also, be careful with plastic calipers, they are very fragile and can break during installation.

• If the socket is equipped with a protective overlay for the contact group, then this indicates its quality. Such protection helps protect contacts from the external environment, prevents the appearance of surface "walking" currents that cause leakage and heating.

• It is desirable that the terminal tightening screws are located on the front side of the mechanism. We have already mentioned the convenience of this above.
• If the contact group is not visible under the overlay, then it must be carefully removed and make sure that the terminals are equipped with spring clips. It is also desirable to see what a nut is - a piece of tin with a threaded hole or something more powerful.

• All sockets, including double ones, must be equipped with mounting tabs made of normal metal, which will not bend at the slightest effort. When unscrewing the screws responsible for the position of the legs, they must independently be pressed against the socket body using the built-in spring. However, some manufacturers save on springs and simply tighten the paws with an ordinary rubber band, which is used to tighten bunches of greens in the markets. This approach speaks volumes - if you saved on springs, then, for sure, there will still be "jambs" in the design.

• Most of the mechanisms of modern sockets are equipped with the so-called elderly input. In fact, this is just a hole that “passes” only one strand of wire to the clamping terminal. In sockets for 16 Amperes, this is a copper monocore with a cross-sectional area of ​​\u200b\u200b2.5 mm² or a multi-wire core of the same section crimped with NShVI tips. Usually, each of the terminals has two such holes, which gives a hint of the parallel connection of sockets with a cable, which is absolutely not worth doing. The presence of a residential input in the socket with some degree of probability guarantees that dissimilar wires of the most incompatible diameters are not “crammed” under the terminal.

An old lead is certainly a good option for most, but not for professional electricians. For them, this is a kind of “punishment”. The most reliable, both from a mechanical and electrical point of view, is a threaded connection with a screw, washer, terminal and nut, but the wire is not inserted straight, but rolled into a ring with a diameter slightly larger than that of the screw. In terms of contact area, such a connection exceeds what is offered in sockets with an older input by 2-3 times, respectively, and reliability and durability are also higher.

In the olden days, experienced electricians even flattened a ring on an anvil to improve contact. In this way, you can connect several wires, and even make contact with aluminum. The main condition is that each wire must be connected to the previous one only through a steel washer.

In modern sockets, electricians of the “old school” are already deprived of the opportunity to work in their usual ways, and the elderly input, which limits access to the terminal, is a confirmation of this.

Video: How to choose an outlet, an overview of outlets

A brief overview of the characteristics and prices of double sockets

Almost every collection of every manufacturer of electrical equipment includes double sockets. We do not intend to "embrace the immensity" and present models that are in good demand, in which everything is in order with quality and the price is not very "biting".

Miniature	Manufacturer, model	Short description	Average price (June 2018), rub
	Double socket Legrand Valena, 16 A	Built-in double socket with earthing, screw terminals, degree of protection IP20	374
	Double socket Legrand Valena Allure, 16 A	Built-in double socket with earthing and protective shutters, screwless spring terminals, degree of protection, IP21	648
	Double socket Legrand Etika, 16 A	Recessed double socket with earth, without shutters, screw terminals, IP20	186
	Double socket Legrand Quteo, 16 A	Surface-mounted double socket with earthing and shutters, screw terminals, IP21	207
	Socket double waterproof Legrand Quteo, 16 A	Surface-mounted double waterproof socket with grounding, screw terminals, IP44	523
	Double socket Schneider Electric Duet WDE000120, 16 A	Built-in double socket without earth, screw terminals, IP20	110
	Double socket Schneider Electric Duet WDE000226, 16 A	Recessed double socket with earthing and protective shutters, screw terminals, IP20	130
	Double socket Schneider Electric W59 RS16-254-18, 16 A	Built-in double ungrounded socket with protective shutters, screw terminals, IP21	113
	Double socket Schneider Electric Rondo RA16-227B-BI, 16 A	Surface-mounted double waterproof socket with grounding and protective shutters, screw terminals, IP44	245
	Double socket Viko Yasemin, 16 A	Built-in double socket with earth, screw terminals, IP20	80
	Double socket Viko Carre, 16 A	Built-in double socket with earthing and protective shutters, screw terminals, IP21	120

Installation of a double socket

In principle, the installation of a double outlet is no different from the installation of a single one, because the same mounting box is used, the mounting method is the same. Very often, double sockets are installed to replace the old ones, which required seats of a different diameter for their installation, and usually it was larger than the diameter of a modern box of 68 mm. The old-style landing hole could have been a plastic box, a metal cup, or just a bare concrete surface.

Let's briefly consider what steps the installation of a double outlet can consist of.

Image	Process description
Installation of the mounting box "from scratch"
	In the intended place, a hole is drilled with a crown with a diameter of 68 mm to the desired depth. For standard mounting boxes, the depth is 40 mm, for enlarged boxes - 60 mm. the box is tried on in the hole and, if necessary, it is finalized with a chisel.
	To lay the power cable to the mounting hole along a pre-marked route, a strobe with a depth of 20-25 mm is cut. The best way to do this is with a vacuum cleaner.
	The cable VVG, VVGng or NYM 3 * 2.5 mm² is laid in the strobe. The use of flexible wires of the PVS type for stationary laying is unacceptable!
	In the mounting box, a cutout is made for the cable in the right place
	The mounting hole is cleaned of dust and wetted with water from a spray bottle. In a small container, a small amount of gypsum is diluted with water and mixed to a creamy consistency.
	With a narrow spatula, gypsum is smeared into the mounting hole on the back and side walls, and then the mounting box (socket box) with the cable inserted is immediately placed. The mounting box must forcefully enter the hole, squeezing out the plaster. Unfilled cavities are immediately covered with plaster. At the same time, installation is in progress according to the level determined by the marks on the wall and the self-tapping screws screwed into the box.
	After a few minutes, the mounting box will be securely fixed in the hole, and the remaining plaster can be used to cover the strobe.
Installation of a mounting box in an old metal
	In the houses of the old fund, sockets could be mounted in special metal glasses, which are very difficult to remove without disturbing the surrounding finish. Therefore, it is better to make an insert from a plastic mounting box with a diameter of 68 mm. To do this, all lateral protruding parts are first removed with side cutters or a knife.
	With a knife, a cutout is made for the cable entry in the right place in the box.
	The back of the mounting box is cut off with a knife or metal shears.
	The socket box is tried on in place and all protruding parts that prevent it from being located in a metal glass are cut off from it. When fitting the mounting box, it is necessary to maintain the integrity of the holes for the fastening screws. and it is on them that it is necessary to set it horizontally and vertically.
	After fitting the box in a metal cup, it is attached to it with short metal screws with a press washer. Fastening is carried out in three places using a screwdriver with an extension cord. The attachment points must be mutually spaced at 120° and be on solid parts of the plastic.
	Fastening a plastic insert into a metal cup can also be done using Liquid Nails construction glue or a combination of it and self-tapping screws.
Preparing a new cable for installation of a double socket
	First, the presence or absence of voltage in the cable is checked and, if necessary, the corresponding circuit breaker in the shield is turned off.
	The cable is pulled out, the junction box is cleaned inside of all contaminants with a vacuum cleaner.
	From the edge of the mounting box, 5-7 cm of margin is measured on the cable, and the rest is cut off.
	The outer insulation of the cable is removed before entering it into the junction box. The safest way to do this is with a special tool, a Knipex heeled knife.
	From the ends of the wires, the insulation is removed to a length of approximately 12 mm. To do this, it is best to use a special tool - a stripper, which does not damage the wire core.
Socket installation
	The socket is disassembled to find out from which side of the mechanism the wires should fit the terminals.
	With the help of pliers, the wires are shaped in such a way that when connected to the appropriate terminal, the wire would not experience any stress and there would be no pulling force from the terminal. The socket mechanism is tried on wires. The phase (brown wire) is supplied on the left, the working zero (blue wire) is on the right, and the protective zero (yellow-green wire) is in the center.
	The wires are alternately clamped into the corresponding terminals of the socket mechanism.
	When placing the mechanism in the mounting box, you must immediately consider where the wires will be laid so that they do not interfere with the mechanism. It is possible that you will have to give a certain profile so that, for example, they fold like an accordion. The mechanism is attached to the mounting box with two self-tapping screws.
	With the help of a laser or small building level, the mechanism is aligned vertically and horizontally, then the screws for fastening to the box are tightened. After that, you can secure the socket in the mounting box with mounting tabs.
	The socket cover is installed, voltage is applied and its control is carried out.

If a double socket is connected to an existing wiring, then there will be no difference, except that the bare ends of the wires that participated in the previous installation simply bite off, and then the process proceeds as with new ones.

If someone "managed" to see an aluminum wire in his junction box that needs to be connected to a double socket, then certain measures must be taken here. Namely, you first need to switch from aluminum to copper, and then connect the outlet. Modern sockets have brass contacts. This alloy contains the most copper (at least 60%). When an aluminum wire is in the brass terminal, they form a galvanic pair, which will contribute to the rapid destruction of the contact point. The aluminum wire will “melt” especially quickly, and if there is an increased level of humidity in the room, then contact failure, sparking and possible ignition of the arc are “just around the corner”.

There are several ways to switch from aluminum to copper, but by far the easiest and most effective is to use miniature Wago 2273 series terminals with a contact paste that removes the oxide film from aluminum and then protects against re-oxidation. These terminals are small and fit easily into the junction box behind the socket mechanism. To connect, it is enough to remove the insulation from the wire by 11 mm and insert it into the terminal until it stops. In the terminal, solid cores with a cross-sectional area from 0.5 to 2.5 mm² can be connected.

Video: How to replace the outlet in the apartment with your own hands

Video: Installing a Legrand Quteo double outlet

Conclusion

Regardless of the mass of criticism about double sockets, they continue to be widely used in home wiring, occupying a middle niche between built-in sockets and outdoor ones. And in the transitional period, when the wiring is not modernized everywhere and meets all modern standards, double sockets play an invaluable role, increasing the security of houses and apartments. Two double outlets means minus one extension cord and minus two tees, and these “things” can cause a lot of trouble.

We recommend that you follow a simple rule for every double socket installed. Never connect two powerful electrical appliances to the same outlet! For example, washing machine and dishwasher; boiler and dishwasher; air conditioning and an electric oven, etc. We also recommend that when choosing a double socket, follow our recommendations and never chase cheapness, since a bad double socket is no better than a tee or extension cord.

Installing a double outlet is often chosen for financial reasons - it is much cheaper than buying several single ones.

Double sockets are more firmly installed in the wall and may look more aesthetically pleasing than single sockets mounted here and there.

Important! The use of double sockets is possible only if certain rules are observed: the total current, when connecting any devices, should not exceed 10 or 16 amperes.

Tools for installing a double socket

To install a double socket, you need the following set of tools:

Screwdriver corresponding to the screws that fasten the socket

Dielectric coated screwdriver

socket box

Cable (if the socket is to be installed, not replaced)

• self-tapping screws

• Multimeter

  Perforator (also - if you want to install an outlet in a new place)

Before you start connecting

Before installing a double socket, it is necessary to carry out a number of preparatory work:

Choose installation location

Lay cable

Install sockets

Choose the right sockets

Installation process

The first thing to do is to protect yourself by de-energizing the outlet.

But even turning off all the machines in the electrical panel, you need to make sure that there is no voltage in the outlet. You can use a multimeter for this.

Now you can start disassembling the socket. To do this, unscrew the fixing screws and remove the trim.

The socket mechanism will open, with which you have to work:

Now you need to use a knife to expose the wires in the socket by 10 mm.

Here they are before us:

Connecting a double socket

In this case, two sockets will be connected to one wiring line, so 6 wires will be needed for the first socket, and a loop of 3 main wires is laid for the second.

The connection goes like this:

That is, the first outlet will receive voltage and transmit it through the loop to the second, parallel outlet.

When connecting the wires, you need to focus on the color marking, usually the black wire is the phase, the blue wire is zero, and the yellow-green wire is ground. Phase and zero must be connected to the extreme terminals, and the ground to the central one.

You can determine the phase, zero and ground using the color marking adopted according to the standard:

You can also use an indicator screwdriver.

It is very important to connect the wires to the socket terminals correctly.

The figure shows that the supply wires must be connected to different terminals. Otherwise, a short circuit will occur and the wiring will burn.

It is also necessary that when connecting the second wire to the main terminal, the material of the connected wires is the same so that the process of metal oxidation does not start.

Important! Complete electrical safety is ensured if the ground wire is connected to the sockets using a branch wire, that is, it remains unbroken.

If everything is correct, then you can tighten the screws.

Now you can move on to fixing the outlet. It is necessary to align the mechanism and securely fix it in the "glass" using the fixing screws and tighten them tightly on the sides of the socket.

Advice! In order to align the outlet and correctly install the decorative overlay, you need to use the lesson, marker and pencil, drawing an even strip and line up with it when fixing the outlet.

The apartment usually has enough free sockets, but it often turns out that at least two devices must be included in one of them. The solution to the problem is very simple, if you take care in advance how to connect a double outlet. This is one of the most reliable ways to solve the problem of drop-out tees once and for all, loosening the contacts of single sockets in parallel.

What are double or triple sockets

The usual socket represents the metal contacts fixed in the dielectric case. Wires are attached to each of them with a bolted connection. A double socket, installed in one socket, consists of the same contacts, only they are made along the edges of the plate and each of them has a bolt fastening for a phase or neutral wire. Since a copper or brass plate in any case has a greater bandwidth than a wire, it is he who is a potential “weak link”, therefore, when connecting a double socket, tightening the contacts must be taken with all due attention.

The circuit diagram for connecting a triple socket is no different from a double socket - the phase and zero are connected to the contacts that are on copper or brass plates. Between themselves, triple sockets structurally differ in triangular or tape. Their second variety is the same double, but with an additional socket for the third plug - all contacts are on solid plates. Triangular, in turn, have to be made from several pieces, connecting them together with rivets. Theoretically, this somewhat reduces the reliability of the contacts, but if you do not violate the operating rules, then the triangular triple socket, installed in one socket, has been working flawlessly for many years.

Why a double socket

The disadvantages of the solution to put a double outlet are very difficult to find. Almost the only argument that is cited against is most likely simply “out of harm” and says that connecting it to the network increases the risk of overload - except for families that have electricians, no one will even think about whether it will “pull” whether one point two powerful electrical appliances.

In practice, to connect such devices that stably consume high current, separate sockets are made, therefore, under normal conditions, several factors must converge for the occurrence of a long-term dangerous overload, the combination of which seems very, very unlikely.

What is the average outlet designed for?

The first point is the current strength that the socket can withstand - usually this parameter is indicated on its cover, less often on the inside. Old Soviet devices, which are now less and less common (they are being replaced almost primarily because of the need to connect modern Europlugs), for the most part, are designed for a current of 6 Amperes. Modern, even of mediocre quality, are already marked 10 (if it is without grounding) or 16 amperes.

What these numbers mean will help you find out the school formula for calculating the power of an electric current - even the humanities should figure it out. P (power) \u003d I (current) * U (voltage), and given that the voltage in the household network is always constant and equals 220 volts, it is quite simple to calculate what the current marking says.

• 220 Volts * 6 Amps = 1320 Watts = 1.3 kW
• 220 Volts * 10 Amps = 2200 Watts = 2.2 kW
• 220 Volts * 16 Amps = 3520 Watts = 3.5 kW

Power of household electrical appliances

You can visualize where you can safely connect a double outlet by comparing the most commonly used electrical appliances:

Considering the recommendations of the PUE: how to properly connect powerful kitchen appliances, boilers and air conditioners - a separate line is always connected to them, it is very difficult to imagine in what situation the installation of a double outlet will entail the simultaneous inclusion of two devices with a total power of more than 2.2 kW. Using an iron at the same time as a vacuum cleaner or a hairdryer is quite problematic - only a microwave oven with an electric kettle remains, but together they work for a maximum of 5-8 minutes, and the margin of safety in electrical engineering is not an empty phrase. Plus, for such electrical appliances, they usually put good 16 Amp sockets.

Installation of double and triple sockets

There is no difference between how to connect a triple socket, double or ordinary - all the steps are exactly the same. Of course, all work must be done with the electricity turned off:

• A hole is drilled in the wall where a socket box and a strobe will be installed, along which the wire will be fed (if installation is performed from scratch).
• A gypsum or cement mortar is being prepared - a little, so that it is enough to fix the socket box in the wall.
• A socket box is installed flush with the wall (the wires are brought inside it, and before that, their ends must be wrapped with electrical tape so that the gypsum mortar does not get on the cores). Then you need to wait the set time for the solution to completely harden - depending on the composition, this can take from 15 minutes to a day.
• Next, the electrical tape is removed from the ends of the wires, if necessary, the required amount of insulation, the cores are inserted into the contact mounts and tightened. Contrary to some opinions, there is no difference how to connect a triple socket (the same applies to double and single) - the phase wire can be clamped both on the right contact and on the left. The main thing is that there is good contact between the core and the terminal, to increase its area, the core can be slightly flattened with pliers.
• Then the inner part is installed in the socket - you don’t have to expose anything here, since it has a limiter with which it is pressed against the wall. When the socket is completely aligned, the spacer legs are tightened, and the limiter is screwed to the socket.
• The last step is to secure the cover - it is bolted to the inside.

At what step you need to turn on the electricity depends solely on the degree of curiosity - the connection is made correctly or not. You can check the voltage immediately after connecting the wires, after installing the inner part in the socket, or after the installation is completely completed.

The process of installing a double socket is shown in this video:

Double and triple sockets, recruited from ordinary

The meaning of such a connection is that the phase and neutral wires are suitable from the junction box to one of the sockets, and the third is connected from its terminals with the next wire, and so on. In fact, these are not double, but twin (triple) sockets that are connected to a separate unit, which is still powered from one wire.

A row of sockets connected in this way is easy to repair - if any part of it fails, then only the broken part will have to be changed.

The wire connecting the socket blocks is selected with the same section as the one that comes to the first of them. If there is no such thing, then without any problems you can take wires with a larger cross-section core, but in no case vice versa - with a load greater than gentle, the wire connected to such contacts will soon begin to heat up and oxidize. Socket blocks are generally installed in places where the use of a large number of powerful devices is not expected, although if the supply and connecting wires of sufficient cross section and the socket contacts are well clamped, then they will freely withstand the operation of the heater in tandem with several more devices.

There is one more nuance when installing socket boxes - they can be installed one at a time, or you can find a whole block that is immediately inserted into the holes drilled in the wall. Otherwise, everything is done in the same way as with a conventional outlet.

A detailed story about connecting the socket block in this video:

What is better to choose

As a result, the use of double and triple sockets is an excellent alternative to the need to connect ordinary carriers, tees and other devices that allow several devices to work from one point at once.

The only rule that you need to remember, without bothering to calculate kilowatts, is not to include several powerful devices, such as heaters, in one outlet or a group of them. In domestic conditions, it is very difficult to imagine a situation when this may be needed, but if such a need arose, then it is better to choose sockets on different, and preferably opposite, walls.