Replacing a switch or connecting an outlet in everyday life is quite common, so everyone should have at least minimal skills in maintaining a home electrical system.

We will try to figure out how to install electrical wiring with our own hands, focusing on the norms of the PUE and observing safety precautions. Also in this article we will consider the features of drafting a project, the rules for introducing electricity into the house and the intricacies of a reliable connection of wires.

First of all, you should understand the structure of the electrical network. It consists of electrical outlets connected to each other and to the power line by various cables and wires, protective devices and circuit breakers, and a ground loop.

Do not confuse wires and cables. The first ones are conductors for internal wiring, which can be single- and multi-core, the second ones consist of several wires united by a common protective sheath.

With an independent electrical wiring device, a huge amount of knowledge and skills are needed: from calculating the wire cross section to the skills of twisting wires and installing junction boxes

Cables can be mounted in the ground, under water, in concrete structures; they are also used for building a home electrical network, if you need to connect powerful appliances or special protection.

Drawing up a project for intra-apartment or intra-house wiring is a responsible and complex matter that requires qualification. There are many principles and norms for installing wires, switches and sockets.

Here are just a few of them:

• it is better to divide the wiring into groups - sockets, lighting, etc., highlighting separate lines for powerful electrical equipment;
• in the drawing, it is necessary to indicate the power points and installation sites of powerful energy consumers (ovens, air conditioners, washing machines);
• location of sockets - from 0.3 m to 1 m from the floor;
• optimal mounting height of switches - 0.8-1 m from the floor;
• more outlets are better - no extension cords are required;
• a separate project - for a low-current system (to protect against interference, the wires are pulled separately from the power lines, with an indent of at least 0.5 m);
• bathroom switches lead to the corridor, etc.

It is very important to correctly lay the wiring itself - internal or external (open / closed type). We recommend that you familiarize yourself with the private house.

Wiring instructions

Consider one of the options in which you can do most of the electrical work yourself. For the most difficult issues, you will have to turn to specialists, but you can drill channels for wiring or connect sockets with switches yourself.

Stage # 1 - wiring layout

The project has already been drawn up, now with the help of a stepladder, a level (laser or bubble), a construction tape measure, a marker, we mark up - we draw horizontal and vertical lines directly on the plaster / concrete slab where the electric mains will be laid.

In addition to straight lines for the location of wires, we mark the places for mounting junction boxes, sockets and switches - we simply circle the circle marker for specific device sizes. The quality of chasing depends on the accuracy of the markup.

You need to start by beating off a horizontal level, which is called the “clean floor level” - that is, the floor with the finished floor covering. It is from him that the distance to sockets and switches is measured.

The power line is laid approximately 0.3 m from the ceiling, a low-current line can be placed half a meter lower. It is not recommended to plan laying next to jambs.

At the time of the start of the marking, it should be completely finished with the laying of the screed and the “wet” plaster. It is recommended to take into account the special conditions for further installation work: air temperature - from + 10ºС and above, humidity - maximum 70%

Be sure to mark the places of installation of powerful electrical appliances (preferably with the main characteristics), the width of the strobe, we equip the places of passage through building structures.

By the end of the marking actions, the walls, floors and ceilings in the rooms should turn into original drawings with bright and clear designations.

Stage # 2 - wall chasing

Half the success of smooth chasing is the right tool:

• wall chaser equipped with a vacuum cleaner;
• perforator (it is desirable that the impact energy be at least 15 J), drills, crowns, drills from the same manufacturer;
• grinder, discs for concrete;
• chisel;
• a hammer.

Hand tools are useful in hard-to-reach areas and where jewelry precision is needed.

Image gallery

The invited specialist in the process of assembling and connecting the shield will be able to identify errors made during the wiring installation process, for example, an incorrectly calculated wire cross-section

It is strictly forbidden to carry out electrical installation work, including preventive maintenance, in apartment buildings with common shields on your own, this is done by specialists from the management company. They also control the operation of metering devices.

Safety Precautions When Installing Electrical Wiring

To protect yourself and those who may happen to be nearby, the following rules must be observed during electrical work:

1. Use only serviceable equipment - power tools, carrying, extension cords.
2. Before starting work, be sure to turn off the power supply using automatic machines and RCDs. In order not to accidentally turn on the voltage at the site, you can hang a sign or warn the neighbors.
3. For insurance, use testers and indicator screwdrivers.
4. Make sure that the insulation on the handles of the tool is in order.
5. Try not to work alone - you may always need help with work or medical care.

Separate rules apply to working with a puncher, wall chaser or a powerful drill. In addition to protective clothing, gloves (with an insulated handheld) and a mask (respirator) are required. Shoes should tightly cover the legs and not slip.

Laying electrical wiring under the ceiling must be done only from the platform: chairs or tables are absolutely not suitable.

Every professional electrician is familiar with the rules for providing first aid in case of electric shock, but, unfortunately, the townsfolk do not always act correctly.

1. Wiring

Wiring called a set of wires and cables with their associated fasteners, supporting, protective structures and parts. This definition, according to the PUE, applies to electrical wiring of power, lighting and secondary circuits with a voltage of up to 1 kV AC and DC, carried out inside buildings and structures, on external walls, territories of enterprises, institutions, microdistricts, courtyards, household plots, construction sites using isolated installation wires of all sections, as well as unarmoured power cables with rubber or plastic insulation in a metal, rubber or plastic sheath with a cross section of phase conductors up to 16 mm (with a cross section of more than 16 mm - cable lines).

Open wiring called wiring laid along the surface of walls, ceilings, trusses, supports and other building elements of buildings and structures, etc.

Open electrical wiring is also performed by current conductors, which are understood as devices consisting of uninsulated or insulated conductors and related insulators, protective sheaths, branch devices, supporting and supporting structures. Depending on the type, conductors are divided into flexible (from wires) and rigid (from rigid tires).

Concealed wiring called wiring laid inside the structural elements of buildings and structures (in walls, floors, foundations, ceilings), as well as on ceilings in floor preparation, directly under a removable floor, etc.

Outdoor wiring called electrical wiring laid along the outer walls of buildings and structures, under sheds, etc., as well as between buildings on supports (no more than four spans up to 25 m each) outside streets, roads, etc. External wiring can be open and hidden.
A tray is an open structure designed for laying wires and cables through it. The tray does not protect against external mechanical damage. Trays must be made of non-combustible materials.

2. General requirements for electrical wiring

Types of wiring and ways of laying wires and cables applied depending on the characteristics of the environment are determined in accordance with the requirements of the EMP. Wires and cables laid in boxes and trays must be marked.

Installation of control cables should be carried out taking into account the requirements for the installation of cable lines.

The passages of unarmoured cables, protected and unprotected wires through fireproof walls (partitions) and interfloor ceilings must be made in pipe sections, or in ducts, or in openings, and through combustible ones - in steel pipe segments.

In industrial premises, the descents to switches, sockets, starting devices are protected from mechanical damage at a height of at least 1.5 m from the floor level or service platform. In amenity premises of industrial enterprises, residential and public buildings, as well as in electrical rooms, these slopes do not protect against mechanical damage.

The smallest allowable bending radius of wires with rubber insulation is taken at least 6d, with plastic - 10d, and with a copper flexible core - 5d, where d is the outer diameter of the wire. The descent to the switches and sockets with open wiring is carried out vertically.

Crossings of openly laid unprotected and protected wires with pipelines (heating, plumbing, etc.) are performed at a distance of at least 0.05 m, and from pipelines with flammable or flammable liquids and gases - at least 0.1 m. At a distance from wires and cables to pipelines less than 0.25 m wires and cables are additionally protected from mechanical damage for a length of at least 0.25 m in each direction from the pipelines.

In parallel with heating pipelines, plumbing, etc., wires and cables are laid at a distance of at least 0.1 m, and pipelines with flammable and flammable liquids and gases - at least 0.4 m.
All connections and branches of the installation wires must be made by welding, crimping in sleeves or using clamps in junction boxes.

Open and hidden laying of installation wires is not allowed at temperatures below 15 °C.

Manual work on punching holes and furrows is mechanized using devices using pneumatic, hydraulic and electrical energy, as well as devices driven by the force of an explosion of powder gases. Small-scale mechanization tools include hand-held electric drills, pneumatic hammers, perforators, hydraulic presses, construction and assembly guns, powder columns, manual and pyrotechnic mandrels, etc.

When fastening wires and devices, plastic and metal duGnmsh, duoyel with fibrous filler and spacer nut, Gyultm, studs, brackets, pins, hooks, and tshszho (Ch1 (| C | | 11.py1Y (1 dowel for construction and assembly gun and manual mandrels.

3. Laying wires in steel pipes

Laying open and hidden electrical wiring in steel pipes requires the expenditure of scarce materials and is laborious in installation. Therefore, they are used to protect wires from mechanical damage, as well as to protect the insulation and the wires themselves from destruction by caustic vapors and gases, moisture, dust and explosive mixtures from the environment entering the pipe.

Connections and connections of pipes to boxes, apparatuses and electrical receivers are performed without special sealing (when they are used to protect wires from mechanical damage), sealed (to protect pipes from dust, moisture, caustic vapors and gases) and explosion-proof to exclude the possibility of ingress inside pipes, apparatuses and electrical receivers of explosive mixtures.

Steel pipes used for electrical wiring are divided into three groups: ordinary water and gas pipes, light and thin-walled electric welded pipes.
Before installation, the inner surface of the pipes is cleaned of scale and burr and the inner and outer surfaces are painted with asphalt varnish.

Pipes laid in concrete are not painted on the outside for better adhesion to concrete. Galvanized pipes are laid without painting. During installation, they adhere to the normalized values ​​\u200b\u200bof the angles and bending radii of pipes, depending on the diameter of the pipes, the number and cross section of the wires laid in them.

Ordinary water and gas pipes are used only in explosive installations; light - in justified (from the point of view of metal savings) cases with open laying in dry and damp rooms; as well as for hidden laying in dry and damp rooms, in attics, in underfloor floors, foundations and other building elements with sealing of entry points into boxes and connecting pipes with steel threaded couplings. Thin-walled electric-welded pipes are used for open laying in dry and damp rooms without sealing the joints and entering the boxes.

Electrical installation organizations use the industrial method of installing steel pipes. Procurement of pipes, their processing, cleaning, painting, picking into separate units and packages is carried out in the MEZ. At the installation site, the pipes are laid in ready-made units, connected to each other and wires are pulled into them.

Procurement of pipe blocks in the MEZ provides for the use of normalized elements in the form of corners with standard bending radii. Pipes are prepared in workshops either according to sketches or models that imitate the location of electrical receivers, to which pipes with wires are connected.

Rice. 1. Connections and inlets of steel pipes into boxes (b):
1 - threaded coupling; 2, 9 - sleeve on screws; 3 - segment
pipes with welding on the edges; 4, 7 - sleeve for welding;
5 - coupling with a socket; 6 - on the thread in the branch pipe of the box;
8 - installation grounding nuts on both sides

Methods for connecting steel pipes are shown in fig. 1. Connection with a threaded coupling is performed with sealing with tow on minium or a special fluoroplastic tape of the FUM brand. Such a connection is mandatory for ordinary and light water and gas pipes in explosive areas, damp, hot rooms, as well as in rooms containing vapors and gases that have a harmful effect on the insulation of wires. In dry, dust-free rooms, it is permissible to connect steel pipes with sleeves or cuffs, without sealing (see Fig. 1, a).

Steel pipes with open laying are fixed with brackets and clamps. It is forbidden to fasten steel pipes of all types to metal structures using electric and gas welding. When laying steel pipes, certain distances between their attachment points must be maintained: no more than 2.5 m for pipes with a nominal bore of 15-20 mm, 3 m - with a passage of 25-32 mm, no more than 4 m - with a passage of 40-80 mm, not more than 6 m - with a passage of 100 mm. Permissible distances between broaching boxes depend on the number of bends in the pipe line: with one - no more than 50 m; with two - no more than 40 m; with three - no more than 20 m. The choice of the diameter of the steel pipe for placing wires in it depends on their number and diameter of the wires.

To avoid damage to the wire insulation during pulling, plastic bushings are installed at the ends of the steel pipes. To facilitate the pulling of wires, talc is blown into the pipes and a steel wire with a diameter of 1.5-3.5 mm is preliminarily tightened, to the end of which a taffeta tape with a ball is attached. Then, a ball is blown into the pipe with compressed air from a small mobile compressor at an overpressure of 200-250 kPa, a wire is pulled in with a taffeta tape, and then a wire or cable attached to the wire.

In vertically laid pipes, it is recommended to tighten the wires from the bottom up. Connections and branches of wires laid in pipes are made in boxes and boxes.

4. Laying wires on cables and strings

Rope wiring. A cable as a supporting element of electrical wiring is a steel wire or rope stretched in the air, designed to suspend wires, cables or their bundles to them.

For laying indoor networks for industrial electrical installations with voltage up to 660 V, APT installation wires are used, which have aluminum conductors, rubber insulation and a carrying cable. The insulated wire cores are twisted around an insulated galvanized cable (wires with a cross section from 2.5 to 35 mm2, two-, three- and four-wire). The wire cores have a distinctive marking in the form of stripes on the surface of the insulation.

For external wiring, AVT brand wire with aluminum conductors, thickened PVC insulation and a carrying cable is used; in agriculture - AVTS wires with aluminum conductors, PVC insulation and a carrying cable. For cable wiring, installation wires are also used. APR (PR), APV (PV) and unarmoured protected cables of brands AVRG (VRG), ANRG (NRG), AVVG (VVG), which are attached to a special carrier cable.
Installation of electrical wiring performed in two stages.

At the first stage, the workshop prepares and assembles electrical wiring elements, complete anchor, tension structures and supporting devices and transport them to the installation site.

At the second stage of installation, cable wiring is mounted on pre-installed tension devices and hangers in the premises.
When preparing cable wiring in the workshop, branch, junction and inlet boxes, grounding jumpers, tension couplings are installed and fixed on it. Luminaires are attached to the wiring, as a rule, at the second stage of installation, when the cable wiring is unwound on the floor, temporarily suspended at a height of 1.2-1.6 m for straightening wires, suspension and connection of luminaires (if they were not mounted on a cable line in workshops). Then the electrical wiring is lifted to the design site, the cable is fixed at one end to the anchor structure, connected to intermediate hangers and ties, pre-tensioned (manually for spans up to 15 m and with a winch for large spans) and put on the second anchor hook. After that, the final tension and grounding of the carrier cable and all metal parts of the line, the adjustment of the sag, and the connection of the line to the supply line are carried out (Fig. 2).

Rice. 2. Scheme of assembly and suspension of cable wiring at the installation site:
1 - temporary and permanent anchors; 2 - tension clutch; 3 - end loops; 4 - special winch or chain hoist;
5 - free end of the carrier cable; 6 - auxiliary cable segment; 7 - wedge clamp; 8 - lash of cable wiring; 9 - inventory stands; 10 - dynamometer; 11 - vertical wire suspension

A manual winch is used to tension the cable. The cable tension is controlled by a dynamometer.

The sag during adjustment is taken equal to: 100-150 mm for a span of 6 m; 200-250 mm for a span of 12 m. The carrying cables are grounded at two points at the ends of the line. On lines with a neutral wire, grounding is carried out by connecting the carrier cable to the wire with a flexible copper jumper with a cross section of 2.5 mm, and on lines with isolated neutral, by connecting the cable to the bus connected to the ground loop. The carrier cable is not used as a grounding conductor.

String wiring. string wiring used for fastening cables of SRG, ASRG, VRG, AVRG, VVG, AVVG, NRG, ANRG brands, STPRF and PRGT wires on hard grounds. Such wiring is performed on a stretched steel wire (string) or tape fixed close to the building foundations (ceilings, trusses, beams, walls, columns, etc.). All elements of string electrical wiring are reliably grounded.

5. Installation of busbars with voltage up to 1 kV

Busbars are divided into: main three-phase alternating current (ser. ShMA) for rated currents of 1600, 2500 and 4000 A; main direct current (ser. ShMAD) for rated currents 1600, 2500, 4000 and 6300 A; distribution (ser. ShRA) for rated currents of 250, 400 and 630 A (their kit includes straight, angled and tee sections, input and branch boxes with automatic switches or circuit breakers with fuses for connecting electrical receivers for voltage 380/220 V); trolley (ser. ШТМ) for nominal points of 200 and 400 A (for power trolleys for overhead cranes, electric hoists and power tools); lighting (ser. ShOS) for rated currents of 25, 63 and 100 A (for lighting networks in rooms with a normal environment).

The section of the SCO series is a box, inside which four insulated copper conductors with a cross section of 6 mm2 are laid. Every 0.5 m, places are provided for plug-in connection of single-phase power receivers according to the phase-zero scheme. To connect the sections to each other, four-pole plug-in end connections are provided.
With the current state of organization and installation technology, busbar sections in workshops are assembled into enlarged blocks, which are then mounted in the workshops of enterprises under construction.

Busbar installation at the construction site is reduced to their assembly and installation. Bus ducts are mounted on trusses, columns, walls using brackets or suspensions, as well as on the floor on special racks (mainly closed distribution bus ducts). Sections of busbars are pre-assembled into blocks of three and four sections, and then installed on supporting structures.

6. Wiring in hazardous areas

In hazardous areas of all classes, cables with PVC, rubber and paper insulation in PVC, rubber and lead sheaths and wires with PVC and rubber insulation in water and gas pipes are used. The use of cables and wires with polyethylene insulation and cables in a polyethylene sheath in explosive zones of all classes is prohibited.

In explosive zones of classes B-1 and B-1a, cables and wires with copper conductors are used only; in zones of classes V-16, V-1g, V-1a and V-11 - cables and wires with aluminum conductors and cables in an aluminum sheath. In explosive zones of all classes, uninsulated (bare) conductors, including down conductors to cranes, electric hoists, etc., are not used.

Methods for laying wires and cables choose based on recommendations. PUE. In power networks with voltages up to 1 kV, a special fourth core of a cable or wire is used for grounding or grounding.

In zones of classes B-1, B-1a, B-11 and B-11a, the passages of openly laid single cables through walls and ceilings are made through pipe sections embedded in them, the end of which is sealed with a pipe gland. When cables pass to an adjacent explosive room, pipe glands are installed from the side of an explosive room of a higher class, and for the same classes of rooms - from the side of a room containing explosive mixtures of a higher category and group. In class B-1 rooms, pipe seals are installed on both sides of the passage. When cables pass through ceilings, pipe sections are released from the floor by 0.15-0.2 m. Cable passages through walls in explosive rooms are performed in accordance with fig. 3.

If necessary protect wires and cables from mechanical or chemical influences, they are enclosed in steel water and gas pipes. For connections, branches and pulling wires and cables in steel pipes, cast iron explosion-proof boxes of series B (fittings) are used (Fig. 4).

In damp rooms, pipelines are laid with a slope towards junction and pull boxes, and in especially damp rooms and outside - towards special catchment pipes. In dry and humid rooms, the slope towards the boxes is done only where condensation can form.

Rice. Fig. 3. Cable passages through the internal walls of rooms with US-65 sealing compound (a) and gland seal (b):
1 - ground bolt; 2 - pipe section; 3 - cable;
4 - seals made of cable jute or asbestos cord;
5 - sealing compound US-65; 6 - cement mortar;
7 - stuffing box (L is the length of the stuffing box); 8 - rubber sealing
ring; 9 - washer

Rice. 4. Explosion-proof cast-iron boxes: o - straight through passage (checkpoint); b - passage through the bottom (efficiency);
c - tee branch (CTO); g - tee with
branch to the bottom (KTD); d - cross branch (KKO);
e - passage dividing (KPR); g - checkpoint
separating for local tests (KPL)

The pipes are connected to each other, as well as to fittings, boxes, boxes, inlet fittings of machines, casings of apparatuses and lamps, on a thread with a winding of hemp yarn impregnated with drying oil or paints rubbed in oil (red lead, whitewash), or FUM tapes (fluoride sealant - ny material) with a width of 10-15 mm. PVC tape and other insulating materials must not be used to seal threaded connections. Connection and fastening of pipes by welding is also not allowed.

To prevent the transfer of an explosive mixture from one room to another or outside, on pipelines in explosive rooms, separating sealing boxes KPP or KPL are installed, providing for the possibility of local tests, filling them with sealing putties and mastics.

Such seals are installed at the points of transition of pipelines from explosive premises of higher classes to explosive premises of lower classes (for example, from a class B-1 room to a class B-1a room. US-65 composition is used as a sealant.

In hazardous areas of any class, electrical installations of all AC and DC voltages are grounded (zeroed). As zero protective (grounding) use only conductors specially designed for this. Additionally, it is allowed to use building structures, steel pipes for electrical wiring, metal sheaths and cable armor for this purpose. Steel pipes are grounded at both ends. Pipes that do not have connections can be grounded in one place.

The device of connecting and branch couplings on cables in explosive installations is prohibited.

7. Testing of internal electrical networks

At the end wiring installation(and busbars), before their acceptance into operation, control tests are carried out.

1. Insulation resistance test power wiring(busbars) is carried out with a 1 kV megger. The insulation resistance must be at least 0.5 MΩ.

The insulation resistance is measured with the fuses removed between adjacent fuses (or behind the last fuses between any wire and earth) and between two wires. When measuring insulation resistance, electrical receivers, as well as devices, devices, etc., must be turned off. When measuring the insulation resistance of the lighting network, the lamps must be unscrewed, and the sockets, switches and group shields connected. The insulation resistances of the busbar trunkings are measured between each busbar and the protective casing, as well as between every two busbars.

2. Insulation test overvoltage 1 kV industrial frequency for 1 min. This test may be replaced by a 1 min measurement of the insulation resistance with a 2.5 kV megger. At the same time, if the value of the insulation resistance is less than 0.5 MΩ, a test with a voltage of 1 kV of industrial frequency is mandatory.

There are many ways to lay wire. It is buried in the ground, immured in the wall, mounted on load-bearing structures, suspended in the air. We will consider the simplest technology in terms of installation: open wiring.

The definition sounds like this: this is a way of laying a cable, in which it is not located in load-bearing structures, and is not hidden under finishing materials. At the same time, the external wiring is properly fixed, that is, it does not sway under the influence of atmospheric phenomena.

Therefore, the laying of air networks between the pillars does not apply to this method. The technology is called "air suspension".

Rules for the installation of electrical networks (PUZ) provide for the following types of laying open (external) electrical wiring:

1. On the surface of vertical walls or floors (ceilings). The method provides for direct fastening of the wire to the surface using special devices. The cable is firmly attached to the wall (ceiling).
2. Laying with point fixings: insulating rollers, hangers. In this case, the open wiring does not touch the surface, but does not have long free sagging sections.
3. String lining. Unlike free suspension, the cable still has no slack. The fundamental difference from the previous methods: a cable is mounted on the bearing surface, and the wire is attached to it. The technology is used when there is a danger of mechanical impact on the wiring.
4. Installation of open wiring in special sleeves (pipes). It can be a rigid structure or a flexible corrugation. The cable is not fixed inside and can be easily removed for replacement or repair. Fixation on the wall is organized by the outer shell.
5. Exposed electrical wiring can be laid in special trays. Professional electricians call them cable growths. Moreover, the guides can be fixed both along the walls (floors) and between objects (supports). This method does not apply to free suspension, since the cables do not have the ability to mix.
6. Installation of external electrical wiring in special boxes. Perhaps the most common way, if necessary, to protect the wires from external influences. Boxes usually have easily removable lids. This allows you to quickly access content.
7. Open wiring in a house or apartment can be laid in decorative elements: hollow architraves, baseboards made of electrical plastic.

Any of the above methods does not contradict the requirements of the PUE, if security measures are observed. Given the availability, and poor protection from mechanical stress, open wiring can cause electric shock.

Therefore, compliance with the Rules is not just a formality, but your life and health.

Safety measures when organizing outdoor wiring

To begin with, let's define the terminology regarding cable products:

• A cable is an insulated conductor that has an additional coating around it, often armored. It must withstand the impact of the external environment without violating the insulation parameters. As a rule, cables are trunk cables; they are rarely used to connect the end user.
• A wire is the same conductor (most often insulated, but non-insulated products are also used: for example, for grounding). An outer sheath may be provided around the main conductors, if necessary. Special strength is not required, just additional insulation.

If the installation of external wiring is carried out with a wire, the presence of a second sheath is highly desirable (at a voltage of more than 42 volts, it is mandatory). Under mechanical action, there is a chance to damage only the outer insulation, but there will be no contact with the bare conductor.

And now the basic security requirements:

• Installation of open wiring on the surface of the walls inside the room is allowed only using a cable, or a wire with an outer sheath. At the same time, the walls (or their decoration) cannot be made of combustible material. This is a method of fastening directly to the surface.

Consider several options for open wiring with examples

Loft open wiring. This fashion trend allows not only to be in trend, but also to save on the aesthetic component. That is, you simply lay the industrial corrugation without worrying about the color and shape matching (this is the loft style). Fasteners and materials can be the cheapest, the main thing is reliability.

Although the premises, finished to order, may look and be evaluated very expensive. But the technology of installing open electrical wiring has nothing to do with this.

Another trend that takes a lot of money is retro-wiring. If you're willing to buy expensive accessories (fiberglass braided wire costs an order of magnitude more than regular wire), you can do the wiring beautifully and safely.

All accessories are made of ceramics. By the way - one of the best dielectrics in terms of fire safety. It makes no sense to organize common harnesses and cable boxes. Vintage design just says that the more wires, the more stylish the room looks.

In addition, the retro style involves laying wires in metal pipes. For wooden premises, the very thing is: both beautiful and fireproof, and the wiring is reliably protected from mechanical stress.

And if these same pipes are also connected to a protective ground, you can not worry that the wiring will break through the phase to the pipe body.

No less aesthetically pleasing, you can organize open wiring in cable boxes. It's a total classic. Initially, professional pipes were used only to optimize bundles with a large number of wires. And today it is a way of laying single cables.

In addition, the modern design of these accessories allows you to fit the box into any interior.

You want a contrasting white color. But no - pick up a cable box with a wood finish: the choice in stores is huge.

Important! Laying wiring in a box has undeniable advantages:

• By opening the lid, you can always add a new conductor (if this does not contradict the PUE restrictions).
• The wires in the box can be used without an outer sheath - again, savings.
• No ties, fastening clips, beautiful styling. The main thing is that there are no knots and creases in the wire. The rest will be hidden under the lid.

The situation is a little more complicated with the so-called electrical skirting boards.

Important! When buying such a product, check with the seller: what type of wiring can be laid in the niche of the decorative element. Otherwise, you will buy a baseboard that is not fireproof, in which you can only mount a telephone or Internet line.

With the only drawback: low capacity, a plinth for open wiring can actually replace chasing.

By using this technology in conjunction with cable routing behind a false ceiling, you can generally leave the walls untouched. In this case, all electrical wiring will be replaced.

Advice! When laying power and signal (telephone, television, Internet) wires together in the plinth, remember about mutual pickups. Ferrite filters at the ends of the wires will not interfere.

Finally, let's talk about the advantages and disadvantages of this method.

What we have in the plus:

• Ease of installation. No hard and dirty work associated with chiselling walls, deepening sockets and switches, and subsequent plastering of the room.
• When organizing a new wiring, there is no need to start repairing the premises. The impact on the interior is minimal.
• Revision access: Wiring is easily inspected at any time.
• Possibility of replacement, modernization, addition of new lines. And all this at any time, without the use of sophisticated equipment.
• If you change your mind - the wire can always be hidden in the wall. But the reverse process is difficult.
• The organization of open wiring is suitable for any premises. But hidden in the walls, it has limitations. For example, it cannot be laid in wooden houses.

There are also disadvantages:

• The main one is that there is no 100% compatibility with the design of the room. If you are not a fan of the vintage or loft style, the only thing left to experiment with open wiring is the garage.
• No matter how strong the sheath is (cable duct, corrugation, etc.), all the same, the probability of damage is higher than that of a cable in a wall.
• The ability to grab the wire with your hands and get an electric shock is negligible. But she is.

What materials are required for installation of open wiring

Cable boxes are fastened with ordinary hardware, or even simply with adhesive tape. Vintage and other "loft" sets are already equipped with no less "old" ceramic rollers and clips. For other methods, you will have to select fastener sets.

Corrugation and cable pipes are conveniently mounted on special clamps.

They have a standard configuration, and allow you to neatly organize "tracks" from any number of wires.

Fastening wires and cables directly to the wall is also carried out with quick mounting clips.

For any size and shape. We just drill a hole in the wall, and drive the fastener there.

Ready-made cable studs are also not difficult to install.

Although at home you will rarely see such a picture.

Outcome

Do not be afraid of open wiring, you can always determine in place: which installation method is suitable for your premises. And for any emergency there is a compromise: a plinth with a cable box inside.

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Consumption ecology. Manor: How to choose the right way to lay electrical wiring in a room, taking into account the features of building structures.

Features of the installation of electrical wiring directly depend on the characteristics of the building materials from which the building is built. And this is due to the fact that any building material has its own degree of fire hazard. In this article, we will consider this dependence, based on the current rules for the installation of electrical installations (7th edition of the PUE, updated on February 12, 2016) and on the practical experience of users of our portal.

Rules for the location of cable routes

The location of cable lines in the room is subject to certain rules:

• wiring in the room must be laid in accordance with strictly horizontal or strictly vertical lines, while turning the cable route is possible only by 90 ° (creating all kinds of diagonals associated with saving conductors is unacceptable);
• horizontal sections of wiring should lie at a distance of 10 ... 15 cm from the ceiling;
• vertical sections of wiring must be at least 10 cm away from door and window openings.

Wiring types

In modern buildings, it is customary to install two types of wiring: hidden and open. Hidden wiring is laid in the voids of building structures or inside walls (in channels made by chasing, drilling, etc.).

Open type wiring is laid directly on the surface of the walls. In this case, the wires are either attached to special insulators or placed in standard cable channels.

When choosing the type of wiring when building a house, you should not be guided by your own preferences, because only SNiPs, GOSTs and PUE should be taken as the basis.

Least of all questions arise from "self-taught builders" if the wiring is mounted on walls made of non-combustible building materials. First, let's talk about such cases.

Installation of wiring on building structures made of non-combustible materials

Modern PUE rules allow the use of wires and cables exclusively with copper conductors in the premises (clause 7.1.34.).

If the room has walls and ceilings made of non-combustible materials (concrete, brick, aerated concrete blocks, ceramic blocks, GWP gypsum boards, etc.), then it is advisable to install hidden wiring in it. Firstly, it is aesthetically pleasing, secondly, it is safe in terms of accidental mechanical damage, and thirdly, the rules of the PUE (clause 7.1.37) fully allow mounting hidden wiring in walls made of non-combustible materials.

In this case, we are talking about living quarters. In attics, in basements (especially in unheated ones) and in technical premises, it is recommended to make open wiring.

The PUE rules state: if the building structure consists of non-combustible materials, then it is allowed to lay monolithic, non-replaceable wiring along it, using technological channels, grooves and voids for this. In this case, it is sufficient to use insulated cables or wires in a protective sheath as conductors (for example, VVG cables). In this case, the wiring is installed without the use of metal pipes, protective corrugations and other additional elements.

If the draft wall is subsequently planned to be plastered, then, as a rule, it is not necessary to resort to chasing the walls for wiring.

Of course, niches for sockets and switches will still have to be created in the wall itself. But dust, and physical work in this case will be much less than with widespread chasing of walls.

As for the power supply scheme: any self-respecting owner should have it. Indeed, in the future it will certainly be needed. The circuit is needed at least so that during the repair of the premises it does not get into the wire connected to electricity with a drill.

If you are laying wiring along walls that are not planned to be plastered in the future, then gating cannot be avoided in this case. You will also have to ditch the walls if the old wiring is being replaced during the overhaul, and there is no need to remove the layer of old plaster.

Is it worth it or not to create horizontal strobes? Is it possible to ditch load-bearing walls and concrete floors? There are no unequivocal answers to these questions among professional builders. Of course, from the point of view of the theory of resistance of materials, man-made grooves can significantly weaken the strength of building structures (just like a thin cut of a glass cutter weakens strong glass). However, the rules of the PUE (clause 7.1.37) allow the laying of electrical networks in the grooves (in the grooves) of walls, partitions and ceilings. The main thing is not to overdo it with the depth of the strobe and with its width.

At the same time, existing technological voids (for example, in floor slabs) should be used to the maximum.

In gates, in steel sleeves, in special trays and technological channels, joint laying of wires and cables belonging to different lines is allowed (with the exception of mutually redundant conductors).

Installation of wiring on building structures made of combustible materials

A lot of questions regarding the rules for installing electrical wiring arise from people who begin to electrify premises from combustible building materials on their own. We are talking mainly about frame and wooden houses. Answers to most questions can be found in the same rules of the PUE.

The design of houses made of combustible building materials allows the installation of both types of wiring (hidden and open). Which one to use depends on the preferences of the homeowner. As for the protective elements that protect the wiring from damage, and the building from fire as a result of a short circuit, their choice depends on the type of cable route.

There are two ways to lay open wiring in a room:

1. Installation of retro wiring.
2. Laying wires in cable channels.

Installation of retro wiring

How the design of the retro wiring complies with the rules of the PUE is a moot point. In this regulation, the creation of this type of wiring is not even considered. However, let's try to understand this issue.

In the case of retro wiring, a special twisted cable ("retro") is mounted directly on the wall, to which it is attached using small insulators. Given that such a conductor has a coating of rayon impregnated with a non-combustible composition, it can well be attributed to the class of wires that do not spread combustion. Therefore, the installation of retro-wiring on walls made of combustible materials does not violate the rules of the PUE.

In accordance with the rules of the PUE, the distance from the conductor to the surface of the combustible material must be at least 10 mm, which is fully ensured by the design of insulators for retro wiring.

If the wire sags a lot, then the distance between the insulators can be reduced to 50 cm.

When installing retro wiring, one important nuance should be taken into account: most modern electrical appliances must be connected to a ground loop without fail. For this reason, a three-core cable should be used as part of the wiring (if one is not on sale, then it is advisable to weave it yourself).

In places where wiring passes through a wall or ceiling made of combustible materials (for example, wood), the cable (wire) must be laid in a metal pipe with localization ability. The ends of the pipe should be sealed with a non-combustible composition (for example, fire-resistant mounting foam).

The localization ability of a pipe is a quality that allows it to withstand short circuits in electrical wiring without burning out the walls of the pipe itself. In order for the pipe to have this ability, its walls must be of a certain thickness:

• for copper conductors with a cross section of up to 2.5 mm², the wall thickness is not standardized;
• for copper conductors with a cross section of 4 mm², the pipe must have a wall thickness of at least 2.8 mm;
• for copper conductors with a cross section of 6–10 mm², the pipe must have a wall thickness of at least 3.2 mm.

Open wiring in cable channels

If open type wiring is laid in cable channels and electrical skirting boards, then cables (wires) with high fire resistance (VVGng or NYM) should be used as conductors. At the same time, the material of the cable channels must also prevent the spread of fire.

Socket boxes when installed on walls made of combustible materials must have fireproof linings (for example, from asbestos cement or gypsum mortar) 10 mm thick. In places where the wiring passes through combustible structures, metal sleeves with localization ability must be installed.

Concealed wiring in combustible walls

Features of laying hidden wiring in walls made of combustible materials (for example, made of wood) boil down to the fact that wiring in the voids of such walls and partitions should run inside metal pipes with localization ability (PUE rules 7.1.38.).

There is only one rule, and in relation to its implementation, there can be no concessions. All other options (the use of plastic corrugations, metal hoses and other protective elements) should be excluded, because from the point of view of fire safety they are unacceptable.

When laying wires and cables on combustible structures (or inside them), in all cases it must be possible to replace the conductors.

By the way, electrical wiring, spread over the floors, is the most convenient way to equip hidden wiring in rooms made of combustible materials. Gates to sockets and switches in this case will simply go down from the main highways.

When laying pipes and ducts for electrical wiring in technological voids of combustible structures, the ends of pipes and ducts should be covered with quickly removed non-combustible material (for example, mounting foam).

In order to create a sufficient number of turns during the installation of replaceable wiring in metal pipes, junction boxes must be used in the corners of the electrical route. Access to these elements should always remain open.

The inner diameter of the pipe must be selected in such a way that the cable laid inside it occupies no more than 40% of the total free space. This rule applies to all protective elements (cable channels, corrugations, trays, etc.).

It should be noted right away that the creation of hidden wiring in rooms with wooden walls is a laborious process. After all, the channels for wiring will have to be equipped on their own. Space for pipes must be freed up by drilling, grooving and creating recesses.

Vertical channels in the walls should be drilled in the process of laying the log house. In this case, horizontal holes are made after the walls are ready. To make it more convenient to pull the cable through the pipes, an auxiliary cable for pulling (conductor) should be laid in advance in their inner lumen.

Cable laying under drywall, behind suspended and stretch ceilings

Laying concealed wiring inside frame partitions, under plasterboard or plastic sheathing, as well as behind various types of ceilings, is regulated by the code of building rules SP 31-110-2003 (clause 14.15) and the rules of the PUE (clause 7.1.38.). In accordance with these regulations, hidden wiring can be mounted in two ways:

1. If partitions, wall bases or their sheathing are made of combustible materials, then conductors (for example, marked VVG) must be placed in metal pipes with localization ability, or in closed boxes.
2. If building structures are made of non-combustible materials, then the wiring should consist of wires (cables) that do not spread combustion (for example, VVGng), while it should be mechanically protected by non-combustible non-metallic boxes or pipes (for example, corrugated self-extinguishing pipe).

In both cases, the wiring must be replaceable.

If the wiring is mounted under the plasterboard sheathing, and the supporting profile is almost close to the wall, then it is advisable to lay the wires in the grooves made in the wall or in the plaster.

When laying conductors under ceilings, under plasterboard or plastic surfaces, as well as inside frame partitions, one should be guided by the general rules for installing electrical wiring on combustible or non-combustible building structures (presented in the previous sections of the article).

Wiring under the floor

Installing electrical wiring under the floor is an ideal way to create hidden cabling without resorting to horizontal wall chasing. The cable (main wire) in this case is brought directly to the locations of sockets, switches and junction boxes.

The method of creating floor wiring directly depends on what material it is planned to make the floors from. In general, it is necessary to focus on the rules of the PUE already known to us.

If the wiring is mounted in the lower layers of the cement floor, then a simple protective corrugation is sufficient for its installation. Of course, it is possible to lay a cable inside the screed without corrugations at all, but in this case it will not work to replace the wiring without destroying the floor covering. By the way, the difficulty of repairing and replacing cables (wires) is the only significant drawback of floor wiring, and it must be taken into account when determining the type of electrical wiring. published

Internal is electrical wiring laid indoors.

External is the wiring laid along the outer walls of buildings and structures, under awnings, as well as between buildings on supports outside the streets and roads.

Open electrical wiring includes wiring laid along the surface of walls, ceilings, along supports and other building elements of buildings and structures.

Hidden wiring completely protects wires and cables from mechanical damage and environmental influences . Concealed wiring can be replaceable and non-replaceable.

1 The criterion for choosing the optimal variant of the designed network.

The main criterion for choosing the optimal variant of the designed network is the reduced discounted costs

economic criterion

capacity, after which the annual operating costs remain unchanged.

When capital investments in the construction of an object are made in one year, after which the object is put into operation with annual costs unchanged over the years,

use the annual present cost formula

There are other criteria for comparing the economic efficiency of the designed network.

NPV - the excess of total cash receipts over total costs, taking into account the inequality of effects related to different points in time.

If only two options for the construction of an object are to be compared, then such a criterion as the payback period can be used instead of the given costs.

SELECTION OF THE OPTION FOR THE DEVELOPMENT OF THE ELECTRIC NETWORK TAKING INTO ACCOUNT

POWER SUPPLY RELIABILITY AND ENVIRONMENTAL REQUIREMENTS

Fundamentally, there are two approaches to taking into account the reliability of power supply when designing the development of an electrical network: regulatory and economic. With a regulatory approach, they rely on the requirements for ensuring the reliability of power supply, set out in the PUE. In other cases, it is advisable to apply an economic approach that uses the concept of economic damage due to undersupply of electricity.

The selected network option should provide the lowest power and voltage losses that meet regulatory requirements.

The design and principle of operation of DC machines

The DC electric machine consists of a fixed part, an inductor and a rotating part of the armature. The inductor consists of a frame, poles with an excitation winding. The excitation winding creates the main magnetic flux. The armature consists of a core, a winding, a collector.

Operating principle

The cross indicates the EMF directed away from us, the dots indicate the EMF directed towards us. We connect the conductors together so that the EMF in them is added.

Two conductors connected in series form one turn or one coil. The EMF of conductors located in the zone of one pole is different in magnitude. The greatest EMF is induced in the conductor located under the middle of the pole, the EMF equal to zero - in the conductor located on the geometric neutral line.

If all conductors are connected in series, then the resulting EMF of the armature winding is zero, there is no current in the winding. Contact brushes divide the armature winding into two parallel branches. In the upper one, an EMF of one direction is induced, in the lower parallel branch, in the opposite direction. The EMF removed by the contact brushes is equal to the sum of the electromotive forces of the conductors located between the brushes.

armature winding equivalent circuit.

In parallel branches, the same emfs act, directed opposite to each other. When connected to the armature winding of the resistance, the same currents arise in parallel branches, a current I I flows through the resistance R H. where C e is a constant.
In DC electrical machines, a collector is used. It is installed on the same shaft with the armature core and consists of separate copper plates isolated from each other and from the armature shaft. Each of the plates is connected to one or more conductors of the armature winding. Fixed contact brushes are superimposed on the collector. With the help of them, the rotating armature winding is connected to the DC network or to the load.