We install wiring in the basement
If you want to minimize the number of engineering networks in the residential area of \u200b\u200byour home, then laying wires in the basement can be a good solution. Indeed, thanks to this arrangement, you not only reduce the risk of electric shock to the residents of the house, but also greatly simplify your tasks associated with its installation.
Although it is worth noting here that the installation of electrical wiring in the basement has its own characteristics, which we will discuss in this article.
When choosing a basement as the location of your engineering networks, it is advisable to locate distribution points here as well. In our case, this is an electrical panel that provides power to all groups of your electrical network.
Its location in the basement has certain limitations, but they are easily feasible and do not require additional capital investments:
- First of all, we note that any electrical panel should be located in a place convenient for maintenance. At the same time, there should be sufficient lighting in this place. In this case, according to VSN 59-88, it should be at least 30 lux when using incandescent lamps and at least 200 lux when using fluorescent lamps.
Note! This is slightly higher than for conventional basement lighting, which, according to BCH 59-88, should be only 10 lux when using incandescent lamps and 200 lux when using fluorescent lamps.
- The next important point, which is mandatory at any location of the shield, is its location on a fireproof base. In this case, the shield itself must be made of fireproof materials and have doors with a lock. In addition, a prerequisite is the opening of the door to the outside.
- If your basement is prone to flooding, consider installing an electrical box above the flood level. By the way, this rule also applies to the installation of electrical wiring in the basement. But in any case, if you do not have a special niche for the electrical panel, then, according to paragraph 11.6 of VSN 59-88, the height of its location must be at least 2.2 meters from the floor level.
Note! The distance from the switchboard to any pipelines must be at least 500 mm. At the same time, in the room in which the shield is installed, the temperature should not fall below +5 ° C, and the room itself should have natural ventilation.
The photo shows the correct installation of the electrical panel.
- Our instruction does not recommend placing electrical panels under the premises of kitchens, toilets and showers due to their possible flooding. In addition, it is impossible to place shut-off and control valves of pipelines and gas networks above electrical panels.
Laying cable lines in the basement
Laying the wire in the basement can be carried out in two ways - hidden and open installation. The choice of laying method depends entirely on your wishes, but the open wiring method is much simpler.
Especially considering that the aesthetic side and free space are not as important here as in the residential area. Therefore, in my opinion, it is easier to use the open installation method, but in this article we will describe the features of laying the wire with both methods.
Open wiring in the basement
An open method of laying electrical wiring often involves the use of thin-walled boxes or metal corrugations. You can also install directly on fireproof structural elements using special fireproof linings (usually an asbestos sheet is used for this).
Note! If your basement is damp, then the use of metal boxes and corrugations, according to Table 2.1.2. PUE (Electrical Installation Rules), prohibited. This is due to the possibility of formation and accumulation of water in such boxes and pipes, which can lead to a decrease in the insulation resistance of wires.
- With an open installation method, pipes or boxes made of fireproof materials should be used. When using sheathed or sheathed cables, mounting directly on structural elements is possible. In some cases, mounting on insulators with a lining of fireproof materials with a thickness of at least 10 mm is possible.
- If the wiring location runs parallel to hot pipelines, it is necessary to provide protection against temperature effects or use wires with an appropriate design.
- When laying wiring and pipelines in parallel, the distance between them must be at least 100 mm. If it is a gas pipeline, then the distance to it must be at least 400 mm.
Open wire laying
- With a simple intersection of electrical wiring and pipelines, the distance between them must be at least 50 mm, with a gas pipeline at least 100 mm. In addition, if the distance between the wires and the pipe is less than 250 mm, then they must be additionally protected from mechanical damage. At the same time, if you do the installation yourself, then ensure a margin of protection of at least 250 mm on each side of the pipeline.
- When using boxes and pipes, the possibility of formation and accumulation of moisture in them should be excluded.
- When installing wires on insulators, the places of passage through structural elements should be additionally insulated with an insulating pipe. In addition, the places where the wire passes from one room to another should be sealed with fireproof materials. This is necessary to eliminate the likelihood of fire spreading through these engineering openings.
Concealed wiring method
The price of the issue of installing hidden wiring is somewhat lower if the laying is carried out on fireproof structures, but if you have combustible structures in the basement, then the cost of such work will be much higher.
Concealed wiring
- It is possible to carry out the installation of electrical wiring in basements by a hidden method on fireproof structures by directly laying any wire. But if there are combustible structures, then a lining of fireproof materials should be used or pipes and ducts should be used. Agree, if you do not have special channels for these purposes, then this work is quite laborious.
- It is important to note that the use of ventilation ducts for electrical wiring is not allowed. In the worst case, crossing such channels with single wires is allowed.
- The rest of the above rules for installing hidden wiring are mandatory when installing any wiring in any premises:
- In places of turns and connection of electrical appliances or taps, it is necessary to leave a supply of wire sufficient for reconnection.
- All connections must be soldered, welded or bolted. The use of twist is prohibited.
- When wiring, it is recommended to use only right angles to avoid problems later.
Conclusion
Having clear requirements imposed by regulatory documents on wiring installed in the basement, you can eliminate the likelihood of emergencies. At the same time, you can see the small aspects of the installation thanks to the numerous videos on our website.
In addition, numerous articles on our website can help you with this.
pogreb-podval.ru
Wiring in the basement: device rules and installation
It should be noted right away that the wiring in the basement can only be done by specialists or those people who are versed in electrics and have certain skills in this area. Experts classify basements as dangerous - the probability of electric shock is quite high here due to the high level of humidity, as well as the presence of concrete or brick walls, dirt floors, many metal elements (including reinforcement), etc.
That is why the electrical wiring in the basement should be carried out by a professional electrician or a person who is familiar with the rules of electrical installation in rooms with an increased risk of electric shock. All work must be carried out in accordance with the rules. Do not use electrical appliances in the basement that are exposed to moisture or biological processes (mold, fungus, corrosion).
It is quite difficult for an amateur to choose suitable materials for wiring in the basement. Cables and wires, which are great for the first floor of a country house, may be prohibited for use in rooms with high humidity.
Features of electrical work in the basement
You may be familiar with the fact that a person's life will only be in danger if the voltage during an electric shock is more than 50 V. That is why the voltage in basements and cellars is reduced to 12 V. This requires the purchase and installation of a step-down transformer operating in a 220 V network.
There will be no problems with the purchase of such a device today - many specialized stores offer a variety of models. If possible, it is best to buy a pulse step-down transformer. This is a modern device that is well suited for permanent operation in the basement. The step-down transformer together with the switch should be placed, if possible, outside the basement. Due to this approach, it turns out that in the basement you will have only the lighting fixture itself and a wire with a voltage of no more than 12 V, which is quite safe for the lives of people living in the house.
A step-down transformer.
Among other things, it is required to provide additional protection against water by placing the lighting lamp in a special glass casing. The casing must be equipped with a sealing rubber so that condensate and moisture do not get inside the lighting fixture. Otherwise, corrosive processes will quickly get to the metal elements. If the lamps are not protected by casings, they will systematically fail.
It should be said about electrical wires. In the basement, it is allowed to use those wires that are designed for the corresponding network load. It is necessary to take into account the fact that if the lighting elements have a similar power, but a different voltage, then the current in the wires will flow differently. The wires that are supposed to be installed in the basement must be selected in accordance with the load current. This is a very important point when installing any electrical wiring.
Wiring principles
If you are using a step-down transformer in your basement for safety, then the wires can essentially be run at any height. However, often specific equipment is installed in the basement or there are other factors that do not allow the use of a step-down transformer. In this case, the wires must be laid at a height of at least 2.5 m.
The electrical installation of all cables and wires in the basement must be carried out by a hidden method. It is best to place them under the plaster layer. In this case, the thickness of the plaster layer should be about 1-2 cm.
In some cases, electrical wiring in the basement is allowed in the usual way:
- if protected wires are used;
- if they are mounted on rollers;
- if they are designed only for outdoor installation;
- if located in metal channels, etc.
If the installation of electrical wiring will be carried out in metal channels, then it must be ensured that the required slope of the pipes is ensured. This is necessary so that moisture cannot accumulate in them. The metal parts of the conduit must be properly grounded to minimize the chance of electric shock if accidentally touched. The wires in the basement are best connected only in junction boxes, which are completely sealed and not exposed to moisture.
Lighting devices that are designed for installation in basements must be completely sealed. As noted above, sockets, switches and other electrical devices that do not need to be used specifically in the basement are best placed outside it (for example, on the ground floor of a building or on the stairs).
How to choose lamps?
Even taking into account the fact that the voltage in the network will be minimal and you are using a step-down transformer, you need to understand that only well-protected lamps can be installed in a room with high humidity, into which moisture cannot penetrate under any circumstances.
Wrong version of the lighting device.
Models must have the following characteristics:
- impact-resistant cover;
- complete tightness and impossibility of accumulation of condensate inside;
- resistance to corrosive processes.
Experts at this stage recommend not to engage in amateur activities. It is forbidden to save money by screwing the simplest light bulb into the cartridge. Moisture will not only cause the lamp to burn out quickly, but can also get into the cartridge, which in some cases leads to a short circuit, the consequences of which, probably, are not worth talking about.
Basement lamp in a protective casing.
Safety and Prevention
Everything that has been said above once again indicates that the choice of electrical devices for basements, as well as any other places with high air humidity, should be made taking into account their protection from moisture, corrosive processes, biological effects, etc.
After the wiring in the basement has been successfully installed, do not forget about the prevention of all electrical devices (sockets, switches, lamps, etc.). Prevention is the foundation of security. It is especially important when the basement is located under a residential building.
It should be noted that, if possible, it is best to entrust the work to professionals who can install the wiring in accordance with all requirements and standards. Amateurs often miss minor aspects that lead to sad consequences later. Save on security is not worth it.
podvaldoma.ru
Electrical wiring in basements and attics
Cellars and cellars, as a rule, are built from fireproof materials and structures (brickwork, reinforced concrete blocks, ceilings, etc.). The floors are usually conductive: earth, concrete, broken bricks, etc. Depending on the condition of the soil, the efficiency of ventilation, the relative humidity of the air, cellars and cellars are classified as damp and especially damp rooms, and according to the degree of danger of electric shock, they are classified as especially dangerous rooms. Increased requirements are imposed on electrical wiring in cellars and basements, namely:
Basement wiring diagram.
- the mains voltage should not be higher than 42 V. For this, step-down transformers should be used;
- conduct electrical wiring directly on the base on insulators and rollers with insulated protected wires or cables. For hidden wiring, it is forbidden to use steel pipes with a wall thickness of 2 mm or less;
- luminaires of a hermetically sealed design should be used to prevent moisture from entering the electric cartridge;
- the switch should be located outside the cellar and basement.
Wiring in the attic
Hidden electrical wiring is carried out in walls and ceilings made of fireproof materials at any height.
Open electrical wiring in the attic is carried out with wires and cables with copper conductors.
Wires and cables with aluminum conductors can be laid in buildings with fireproof floors, provided they are laid in steel pipes or hidden in fireproof walls and ceilings.
Marking distances for electrical wiring on rollers: a - for laying tracks; b - for installing switches; c - to bypass obstacles: 1 - funnel; 2 - rubber semi-solid tube; 3 - heating pipe.
Transit lines in attics up to 5 m long are allowed to be made with wires with aluminum conductors. When laying steel pipes, it is necessary to exclude the penetration of dust into pipes and junction boxes, for which sealed threaded connections are used.
Pipes can only be connected with threaded couplings without seals in dry and dust-free attics. Pipes are laid with a slope so that moisture cannot accumulate in them.
Connections and branches of copper or aluminum cores of wires and cables are carried out in metal junction (branch) boxes by pressure welding or using clamps corresponding to the material, cross section and number of cores.
Branches from lines laid in the attic to electrical receivers installed outside the attics are allowed provided that both the line and the branches are laid openly in steel pipes, hidden in fireproof walls and ceilings.
Switching devices in the circuits that feed the lamps located directly in the attics are installed outside the attics, for example, at the entrance to the attic.
Steel pipes, metal housings of fixtures and other metal structures of electrical wiring must be neutralized. It is forbidden to lay any non-metallic pipes in attics.
fazaa.ru
Electricity supply of basements and cellars | School repair
The power supply of the basement or cellar is no less important in their arrangement and operation than the provision of normal ventilation (air exchange in the room).
The main work on the power supply of cellars or cellars consists in connecting the power cable, installing sockets, switches, lamp holders and connecting end users (devices).
To perform the above work, you will need both mechanical and electrical tools:
Screwdriver Set;
Pliers with insulated handles;
Scissors;
Side cutters with insulated handles;
Electric soldering iron;
Hacksaw for metal;
File;
Mounting chisel for making holes and strobes;
Hammer;
Electric drill;
Set of drills;
Insulating tape.
All fastening tools used in the power supply of premises must be serviceable and easy to use, cutting tools must be sharp and properly sharpened.
Preparation of materials for power supply of premises
As a rule, copper or aluminum wires and cables of different sections are used for electrical wiring. Copper wiring is superior to aluminum in many respects, since its main quality is resistance to bending. But nevertheless, it is better to choose one or another material based on what material was used when laying electrical wiring throughout the house, since it is better not to combine these two different materials. The operating temperature of wiring in rubber insulation should not exceed 60-65 °C, and in plastic insulation not more than 65-70 °C. And at the junctions of copper and aluminum wires, this temperature increases significantly due to the difference in support. Therefore, even if you have to connect them, you must use a special connection.
The cross section of the wires should be selected based on the maximum value of the current that heats the insulation, taking into account the mechanical load on the wires, including in the terminal clamps of the electrical wiring terminals.
As for laying several wires in special corrugated pipes, the value of the allowable current in them should be reduced by 15–25%, this is due to the fact that they will heat each other. In addition, in the hidden wiring channels, the cooling conditions are somewhat worse.
The size of the cross section of the cable cores at low current, especially in screw terminals, is determined by the mechanical strength of the conductor. The cross section of the conductor cable must not be less than 2.0 mm2 for an aluminum conductor and 1.5 mm2 for a copper conductor. If it is necessary to carry out open wiring on rollers indoors, then the cross section of the aluminum cable core should not be less than 2.5 mm2.
Probably the main disadvantage of aluminum wires is that they are quite difficult to connect. On the surface of aluminum wires there is a hard and refractory oxide film (it is formed by the reaction of aluminum with atmospheric oxygen), which is a rather poor conductor.
Before connecting aluminum wires, the oxide film must be removed by stripping. However, this is not for long, it is formed again, which, when soldering, prevents adhesion to the solder, and when welding, it completely forms unwanted inclusions in the melt.
The oxide film begins to melt only at a temperature of 1500 - 2000 ° C, which is almost 3 times higher than the melting temperature of aluminum itself. Second in line among the disadvantages of aluminum wire when laying electrical wiring is the low yield strength, especially manifested in screw terminals. The aluminum wire is squeezed out from under the clamp, thereby weakening the contact.
During operation, the leashes should not be subjected to tension and should be located in places where they can be easily inspected and, if necessary, repaired.
For laying aluminum wiring, it is necessary to use connecting parts with aluminum wires with anti-corrosion galvanized coating. The same requirement applies to steel parts.
To connect the wires, it is necessary to cut off the insulation at their ends. Then the wire is prepared for work (if it is a multi-wire cable core), that is, a tight flagellum is made.
To ensure greater reliability of contact, the cores must be cleaned with fine sandpaper, which is lubricated with petroleum jelly before use. After that, the end of the core is bent into a ring with the help of round-nose pliers or pliers, the diameter of which depends on the diameter of the clamp screw.
The ring must be bent clockwise, this will prevent it from unwinding when the screw is tightened. Tighten the nut or clamping screw until the grower is fully compressed (spring washer).
When soldering, tin-lead solders of the POS-30 or POS-40 type are used as a connecting material, they differ from each other only in the percentage of tin. Tin-lead solders begin to melt at a temperature of 226 and 235 °C.
To better connect the solder to the copper wire, a flux is used, which is rosin, which is usually used in the form of a 20% alcohol solution. Before soldering the wires, their connecting cores are cleaned with fine sandpaper and tinned.
There are many ways to connect electrical wires. But knowing all the ways to connect electrical wires when laying wiring in the basement or cellar of a private house is not at all necessary, a few are enough, the main ones are shown in the figure below (an example in Fig. 158). In your case, you can determine the required type of twisting of wires based on the material of the wire core and its cross section. For example, it is advisable to solder aluminum conductors of wires, having previously twisted them with a groove.
Rice. 158. Types of twisting wires:
a - parallel; b - sequential
With this connection, under a layer of molten tin-lead solder, the strands of aluminum wires will be protected from the formation of an oxide film on their surface.
To connect wires of large cross sections, the so-called bandage twist is used.
For the same purpose, you can use a combination of bandage twist with a groove. As a rule, the bandage is made using copper wire with a cross-sectional diameter of their cores from 0.6 to 1.5 mm, which is pre-tinned.
The cores of stranded wires must be stripped, braided and only then twisted (example in Fig. 159).
Rice. 159. Twisting stranded wires
Splicing wires ensures more reliable operation of the power line. Therefore, the rules of twisting must be taken with all responsibility.
A simple twisting method is to strip the ends of a 35-45 mm long steel wire with a fine file or sandpaper, which are tightly twisted.
The remaining ends after twisting are carefully cut off or cut off with a file, and the extreme turns are pressed with pliers.
Splicing of wires using the bandage twisting method is carried out as follows: the stripped ends of the wires are clamped in a vice and wrapped with soft pre-stripped and tinned wire.
After connection, the ends of the wires are bent at a right angle and 9–11 turns of the bandage are made.
The twist and all adjacent stripped wire sections must be protected from corrosion, for this they are covered with special bitumen, asphalt-bitumen varnish or simply covered with oil paint.
Installation work
There are 2 main types of wiring - indoor and outdoor.
The name outdoor wiring comes from the fact that the wires are laid along the outer walls of buildings under canopies and cornices. At the same time, the wires of the external electrical wiring are located in such a way that it was impossible to touch them. It is especially important if the wiring is laid openly along the walls of the building.
Internal wiring is laid inside walls, ceilings, foundations, ceilings, under or removable floors. Hidden wiring can be laid in pipes, flexible metal hoses, voids in building structures, strobes under plaster.
Important: When installing and adjusting electrical wiring, you must be extremely careful, as non-compliance or violation of safety measures, as a rule, leads to severe burns and injuries.
In a room where the relative humidity does not exceed 55-60%, all existing types of wiring can be used.
As for cellars and basements, in these rooms the relative humidity of the air, as a rule, is more than 76%. Therefore, in cellars, open or hidden wiring can only be used with insulated protected or unprotected wires located in special pipes.
When installing a hidden installation, pipes and channels are closed along their entire length to a depth of at least 1.0 cm, and wires to a depth of at least 0.5 cm.
It should be noted that the installation of hidden wiring in pipes is more convenient. It is more convenient that in case of repair or replacement of wires they are easy to replace. It is enough to connect the old and new wire, after which the old one is pulled out and thus the new one is laid.
It is also very important to clarify that laying two-wire or three-wire power lines in pipes and channels is not allowed.
The wiring to the lighting fixtures is laid from above through the ceiling, the wiring to the socket and the switch is laid indoors from below. At the exit of the channels from the panels and ceilings, there are wire connection nodes in the junction box (example in Fig. 160).
Rice. 160. Connection of wires in a junction box
All ends of the wires are welded, insulated and sealed with cement or gypsum mortar.
Connection of wires in the junction box
Before proceeding with the installation of electrical wiring, it is necessary to determine the exact installation locations of the group shield, lamp holders and sockets. Then you need to mark the paths for laying wires, the places of their turns, as well as passages through the walls.
If you plan to install open wiring, then you need to mark all the places where the wires are attached.
Ceiling lamps are hung on special metal hooks, which are pre-fixed in the ceiling holes (example in Fig. 161).
Rice. 161. Fittings for fixing fixtures
Naturally, the metal hooks must be isolated from the suspension fixtures, and for this you need plastic or rubber tubes.
According to the standards, horizontal wiring is carried out parallel to the line of intersection of the walls with the ceiling at a distance of about 10–25 cm.
Electrical mains of plug sockets are laid strictly horizontally, and all descents and ascents of wires to sockets, switches and lamps - strictly along a vertical line. On the ceiling, the wiring is laid with flat wires along the shortest route between the junction box and the fixtures. In this case, it is necessary to ensure that the electrical wires do not cross and are not subjected to mechanical stress, stretching or damage.
The distance from parallel electrical wiring lines or from junction boxes to metal pipelines (water supply or heating) should not be less than 10-15 cm. And if for some reason the wiring line crosses the pipeline, then the distance from it to the pipe at the intersection is not must be less than 6 cm.
To fasten the wires of external wiring, special plastic fasteners or home-made tin brackets are used, which are tin strips 1.0 cm wide. These strips are attached to the wall using dowel-nails.
The wire is attached to the wall at a distance of no more than 40-45 cm. And if the wires intersect, then the attachment points are determined no more than 5-7 cm from the center of the intersection of the wires.
If the wires are fastened to a wooden wall, then the gap between the fastening points should be approximately 30–35 cm. And in this case, the junction boxes are fastened to a wooden base with screws.
After marking and measuring the necessary sections of the wiring, the wires are cut, while it is necessary to leave a small margin at each end of the wire after installation, they will be cut off.
The cut wires must be straightened, for this it is enough to stretch them 2-3 times through a rag held in the palm of your hand. According to preliminary marking or strobes, brackets for fastening wires are strengthened in a concrete or brick wall.
The wires under the metal bracket must be protected by a layer of insulating tape (example in Fig. 162). And in order to be able to reconnect the wires in the junction box in the future, change the socket, switch or cartridge, and at the same time not completely change the wiring section, the ends of the wires inserted into the junction and wiring boxes should have a small margin of about 7-8 cm .
The section of wires inserted into the box must be separated, that is, part of the flat separating base of the wire must be cut out. In this case, it is necessary to ensure that the divided section of the wire does not extend beyond the box.
Rice. 162. Fastening flat wires with metal staples
From the action of moisture contained in the air on the cores of the wires, it leads to their oxidation, which often leads to a break in the contact and disruption of the wiring as a whole.
In order to avoid this, it is necessary to carefully insulate the connections, i.e. the ends of the wires in the junction boxes. Contacts are insulated using electrical tape or other modern liquid insulating materials that are welded onto the ends of the wire cores.
After the ends of the wires are insulated, they are placed in the box so that they do not touch each other in any case, since there is always a risk that a short circuit will occur as a result of which the insulating material may be damaged, after which the box is closed with a lid.
When installing open-type wiring, protected-type switches and sockets are installed on plastic, ceramic or wooden sockets pre-mounted on the wall.
The diameter of the socket boxes used should be approximately 1-1.5 cm larger than the dimensions of the devices installed on them.
The wiring technology of cables is very similar to the technology of laying conventional wires. But, nevertheless, the conductive cores are attached in a slightly different way.
To fasten light unarmored cables on walls with two or more cores, metal brackets with one foot or brackets with buckles previously attached to the basement wall are used (an example in Fig. 163).
Rice. 163. Fastening cables with various brackets:
1 - with one foot; 2 - with two paws; 3 - with a buckle.
Accordingly, for laying 2 or more cables in parallel, brackets with two legs are used.
Brackets are attached to stone walls with dowels, and to wooden walls with wood screws. In this case, the cable attachment points should be located at a distance of no more than 45-55 cm from each other.
When turning the power line, the bending radius of the cable must be equal to 10 times its diameter. The first bracket is located 1.5-2.0 cm from the beginning of the cable bend.
Before connecting the cable to a socket or switch, it must be additionally fixed to the wall at a distance of about 7–11 cm from the input point, and only then should the installation be carried out.
When laying electrical wiring in rooms with high humidity, such as a cellar or basement, steel, polyethylene, polypropylene and vinyl plastic pipes, metal flexible sleeves (corrugations) are used.
As for the marking of protective pipes, it begins with the location of their ends, suitable for electrical panels, electrical receivers and other control devices. After that, the entire route is marked out, determining the installation locations of junction boxes, turning angles and attachment points.
Before proceeding with the installation of the pipe, it is necessary to carefully examine and prepare, that is, if any damage is found, these sections must be replaced. After that, metal pipes must be cleaned of all kinds of dirt and rust and painted, if possible, not only outside, but also inside.
With the use of plastic pipes, a number of problems automatically disappear, for example, they do not need to be painted, and it also allows you to avoid connections at the turns of the route, since plastic pipes are easily bent by preheating them in hot water at a water temperature of 100–110 ° C, it is enough 10-15 minutes.
However, the use of plastic pipes is allowed only in indoor areas, despite the fact that the air temperature in them does not exceed 50-55 ° C. Otherwise, the pipes lose their strength and original shape.
And in order to avoid the accumulation of condensate moisture in the protective pipes, the pipes should be laid with a slight slope in any direction, preferably in the direction where it can freely flow out.
All metal wiring elements in pipes must be protected from corrosion and grounded. The connection of pipe sections with hidden wiring is threaded with tow and painted over with red lead or oil paint.
Grounding can be done both with a flexible copper jumper from the pipe to the body, and through the pipe with grounding nuts.
Before pulling the wires, it is necessary to check the installed pipeline; for this, it is enough to blow it with air. Then, if everything is in order and there are no blockages that prevent the wiring, a steel cable with a diameter of 1.5–2.5 mm is pulled into the pipe.
After that, the aligned and straightened wires are attached to this cable and pulled through the pipes.
Connecting electrical wires in pipes is strictly prohibited.
Any connections are made in junction boxes and carefully insulated.
After pulling the wires, it is necessary to check the insulation resistance of the wires between themselves and between each wire and the ground. The norm is considered if this value does not exceed 500 kOhm.
Upon completion of the preliminary marking of the points of attachment of the electrical wires, it is necessary to prepare holes for the fixing material and sockets for the boxes of electrical installation devices.
Holes in the walls can be drilled with a drill or punched with a puncher.
The easiest way to break through cinder-concrete walls or walls with red and silicate bricks.
In order to make a hole in a concrete wall with a granite filler, you will need a special electric rotary percussion machine and a cutting tool (perforator) capable of crushing the filler and drilling out the concrete binder.
All sockets and switches with hidden wiring on brick, slag or cinder-concrete bases are installed in special plastic or ceramic socket boxes. In such boxes there are two holes for hooking the spacer tabs of the socket or switch.
Such boxes can be independently made from roofing iron or tin. Under them, nests are made in the wall with the help of a special crown nozzle, if there is no such nozzle, holes are first drilled around the perimeter with a drill of 8–10 mm, and then the plane of the nest is cut down with a chisel.
If necessary, rearrange the switch or socket, as well as to make narrow grooves in a stone wall to sink wires into them at the intersections with pipes (as mentioned above, the distance from the wire to the metal pipe should not be less than 5 cm), an ordinary chisel or punch is used .
This is what outdoor wiring should look like in a wet room:
Installation of electrical wiring in a corrugated hose
repair-school.com
Petr Kravets
Reading time: 3 minutes
A A
Only artificial lighting can be used in the cellar, but in order to make it, it is necessary to lay engineering networks. The light in the room must be carried out in compliance with all rules and regulations. Each luminaire must be equipped with a special protective structure.
In order to properly conduct light into the cellar, you need not only to pay attention to how the cable is laid, but also to the selection of equipment. Traditional incandescent lamps, which are mounted without installing a ceiling, will not work in this case, since moisture easily penetrates into the cartridge and causes unpleasant consequences.
It is better to take models that are completely isolated from the effects of condensate and water. As a rule, they are intended for lighting streets and garages. Such devices are equipped with a body that is not subject to corrosion and has a low weight.
When connecting, you need to use only whole pieces of the cable, not using separate parts, even well-connected to each other.
It is necessary to choose the right protection class for lighting devices, not less than ip44, although experts most often advise taking models belonging to the ip57 class. Such equipment can even be in the water, albeit for a short time. From the outside, they are equipped with a metal mesh, that is, they will remain intact even if they are hooked or dropped.
Underground storage facilities are usually built from non-combustible materials such as brick or concrete. In any case, the floor covering is made conductive, made from broken bricks or ordinary soil.
Also, the peculiarities of underground premises include an increased level of dampness, much higher than in ground dwellings. For these reasons, the laying of the electrical cable must be treated with special attention.
Wiring is done taking into account the following requirements:
- The mains voltage is required no more than 42 V. To ensure this indicator, special transformers must be used that lower the values \u200b\u200bto the desired limit;
- The cable is laid through rollers or special insulators. If the wiring is supposed to be hidden, do not use steel pipes with a thickness of less than 2 mm;
- Installation of lighting using special fixtures is done differently than with typical incandescent lamps. Cartridges must be protected hermetically from moisture penetration;
- Switches must not be installed indoors. Their location is allowed only in adjacent and dry rooms or outside;
- All luminaire suspensions must withstand loads 5 times higher than the mains voltage. Before starting installation, the fastening is checked for the absence of deformations, defects or damage, leading to damage to the line and collapse of the entire network.
Installation of electrical wiring
Cellars and cellars belong to the underground premises, which are characterized by particular dampness. This also leads to special conditions for the installation of lighting.
Underground rooms are made of non-combustible materials, but flooring conducts electricity well, since the humidity level is quite high.
This circumstance requires special attention when wiring lighting into the interior. It is not very difficult to conduct light in the cellar with your own hands, but if the owner is not confident in his abilities, you should involve specialists who will perform all the work in full compliance with the requirements and safety standards for working with electrical equipment.
When installing fixtures, care must be taken to install a special separate transformer with a voltage of 220 W.
All wiring is laid at a distance of about 2 meters from the floor line, but not lower. If there is a need to make sockets, they are made at least 1 meter above the floor using special protective devices that are resistant to moisture. Such sockets are equipped with a lid that closes tightly.
Such equipment can be placed even on fences and open terraces, in places with an aggressive environment.
Experts recommend the installation of circuit breakers, since ordinary ones melt too much in underground rooms. The wiring is made exclusively new, since all devices can work for current leakage, and cable defects in this case are unacceptable.
When laying the cable, the cross section is selected based on the total power consumption. As a rule, 2.5 square millimeters is sufficient. If you intend to use powerful equipment, a welding machine, for example, you need a cable with an increased cross section of up to 4 square millimeters, sometimes up to 6 square millimeters.
But, as a rule, such an expense is not required in the cellars, so it is quite possible to use 2.5 square millimeters for the cable. Shields are used exclusively metal, placing in the driest part of the room, and better - in adjacent rooms.
Wiring Options
In order to make lighting in the cellar or basement, you need to use either an internal cable installation or an external one.
In simple basements, you can do it externally, laying and fixing the cable neatly on the surface through cable channels or protective covers. In this case, all networks will remain in the free access zone for regular repair and testing work, if necessary.
The internal wiring method is done only in the case when the cellar is combined with storage facilities for equipment, garden fertilizers and other similar things. Such options are not recommended by specialists due to the high cost and complexity of maintenance.
The difference between electrical wiring in the basement and cellar
Many owners are interested in the question of whether there is a difference between wiring lighting in the basement and in the cellar. Both rooms are characterized by high humidity, which negatively affects all networks and communications, which require increased protection in both cases.
There are also some differences. If for the basement you can run a cable in a protective casing and use special lighting fixtures, then in the cellar all work is much more difficult.
In those rooms where they store not only inventory and equipment, but also food and food supplies, there is a chance of damaging the cable by simply hooking either itself or the lamp.
To avoid this, the wires are placed in protective casings, fixed to the walls and ceiling surfaces. For this, special boxes for engineering networks are used, which performs a protective function against mechanical damage.
In basements, although there is increased humidity, there is still no aggressive environment. In some cases, they have a cellar equipped for storing products and garden materials. Also, fertilizers and impurities for the soil, preparations for disinfection, and toxic substances are stored in the cellars. All of them negatively affect the wiring, eventually ensuring its unusability.
For lighting in the cellar choose the best equipment and cable. It is important to conduct regular inspections of all instrument fixtures and cables, shields, sockets and switches.
Sockets do not install switches indoors, but even with an external location, they still need to be checked periodically. In all other respects, the lighting wiring in the basement and cellar do not differ from each other. It is not recommended to use simple wires that are used for ground living rooms.
In the cellars it is forbidden to use natural lighting, preferring its artificial counterpart. This is due to the storage requirement for products that are sensitive to light and temperature. With access to natural light inside, plants and vegetables begin photosynthesis, development and damage to the crop.
The rooms that are located below the zero level of the basement of the building are called basements. They are surrounded on all sides by the earth, which provides relative temperature stability throughout the year and, as a rule, are deprived of natural light.
The operating conditions of basements are associated with high humidity. It results from:
the proximity of groundwater and the technical difficulties of creating building structures with tightness from all sides;
condensation from the air coming from the street into the room when it is cooled.
Applied measures to combat moisture, based on the removal of groundwater, ventilation, the use of exhaust or supply ventilation systems are not always effective. They partially increase the dryness of the air.
Therefore, basements are classified as high-risk rooms, and the safety rules in force during the operation of electrical installations prohibit the use of open 220-volt electrical wiring in them without observing special measures.
Cellars are used:
for technical purposes;
as premises where it is convenient to store agricultural products, vegetables, supplies all year round.
The issue of safe basement lighting can be solved by using:
natural natural light;
artificial electrical sources that do not pose a danger to electric shock to a person.
Basement natural lighting
Typical window designs used in construction are not suitable for basements. But modern technical developments allow the use of light lanterns based on the tunnel effect.
They have an optical system that perceives the light of the sun and effectively transmits it through the light guide into the room. One flashlight can illuminate an area of about 9 square meters with a luminous flux in cloudy weather comparable to that created by an ordinary 40-watt incandescent light bulb.
In sunny weather, the luminous flux increases by more than 6 times.
The principle of operation of the tunnel lantern is based on the use of an external element - a dome, which collects, concentrates light energy, transmits it through a light guide with reflective walls and illuminates the volume of the room with an internal element - a diffuser.
The fiber optic tube can be rigid or flexible and can be up to 6 meters long.
Tunnel lights are produced by many manufacturers with different specifications. They have tightness, retain heat well, and are gaining popularity in construction.
Basement electrical lighting
Typical mistakes of "home masters", or how not to do electrical wiring
Individual owners of basements "blindly" copy those actions for laying electrical wiring that are performed by electricians in the apartment. They misunderstand the risks of the dangers to which they expose themselves and loved ones.
Main mistake lies in the fact that a voltage of 220 volts is used for lighting, which is used even without its circuit breakers and is supplied from.
Selection and installation of fixtures
The photograph shows the installation of a luminaire sealed in the past with a grill protecting the glass cylinder, the metal body of which was corroded by rust. Through the gaps formed, condensate from the air settles on the electrical contacts of the cartridge and the lamp, creating a path for current leakage to the ground.
The vertical fastening of such a lamp at a low height does not exclude the contact of its body with a person's head. With high humidity, this is very dangerous.
Installing an outlet
At first glance, it can be seen that a special industrial-made dielectric socket block was used for installation, which separates the current-carrying parts of the socket from the wet wall, and the whole structure is securely attached. is that enough?
The wires coming out of the socket are not protected by anything, except for a layer of their own insulation, which is exposed to moisture.
The model of the installed outlet does not have any protection against the ingress of condensate, which constantly oxidizes its metal parts and creates the prerequisites for the appearance of leakage currents.
In rooms with high humidity, the installation of sockets for powering electrical appliances at 220 volts is prohibited by the rules.
Switch installation
An ordinary switch designed for use in dry residential areas is mounted on a wooden board fixed to the wall. Condensation from humid air not only affects the metal parts of the switch, but also contributes to the decay of wood, which will lose its mechanical properties over time.
Electric wires
If you carefully examine the photograph, you can see that special “noodle” wires with reinforced insulation were used as current conductors for lighting, which are designed to work in telephone networks and can be operated in closed trenches underground.
Their copper conductors are made with a cross section of 1 square, which, in principle, is sufficient for the loads created by a single incandescent bulb.
However, connecting the outlet to this circuit determines the possibility of overloading the created electrical wiring, which, moreover, is laid openly along the walls without the use of protective pipelines, boxes and other elements.
How to make basement lighting safe
The choice of scheme and method of protection for electrical wiring
A safe way to use lighting inside a basement is to use fixtures powered by 36 volts or less. For this purpose, a step-down isolation transformer is used.
To place it, it is recommended to use a hermetic industrial-made switchboard, which is mounted not in the basement itself, but at the entrance to it. Other switching and protective devices are also located there.
It is better to connect the contacts of the basement light switch to the phase of the transformer supply circuit. This will shorten its idle time.
The electrical cable from the step-down transformer to the basement lights must be mounted in a single structure without the use of junction boxes. Its input must exclude the ingress of condensate into the luminaire.
Electrical sockets are not allowed inside the basement.
Choice of cable and wires, mounting methods
Individual wires without external protection for basement wiring can lose their insulating properties for various reasons. Their use is prohibited.
To power the luminaires, it is necessary to use only cables, and with reinforced double insulation, which ensures the sealing of current-carrying wires. As an example, we can recommend the cable brand KVVGng.
Even such a cable must be protected from mechanical damage by placing it inside pipelines or special boxes.
Selection of transformers for electrical wiring
The main indicator when choosing a design should be the allowable power consumption, and not just the output voltage. After all, the load currents in the 36 volt network differ from those that exist in 220 volt circuits.
Consider an example of using a 40-watt incandescent light bulb in circuits of different voltages.
In network 220, its current will be 40/220=0.18 amperes. And in a circuit with 36 volts 40/36 = 1.1 A. For 12 volt circuits 40/12 = 3.3 A.
It is impossible to foresee the current consumption of a light bulb that is screwed into a lamp socket in a few years. Therefore, the transformer needs to create a power margin.
The choice of fixtures for electrical wiring
The design of the luminaire should protect the light bulbs from mechanical impact and the penetration of condensate. Glass caps for this are placed inside the grate or made of durable glass.
The use of externally exposed metal parts subject to corrosion should be minimized or avoided.
In low rooms, it is better to place lamps not on the ceiling, but on the upper part of the side walls. This will reduce unwanted contact with them, increase the space in the central part of the room.
Selection of switches for electrical wiring
Ordinary structures for use in dry residential areas are not suitable for working conditions inside the basement. The industry for such purposes produces special sealed switches, protected from moisture penetration.
The recommendations described in the article can be criticized by a large number of opponents who believe that there is no need to complicate the electrical wiring in the basement so much for the sake of periodically visiting it. After all, other people have lighting from 220 volts for decades.
Finishing the article, I would like to ask counter questions: how justified are such risks and is it worth testing your own health with them? Think about it.
Electrical wiring in cellars and cellars
Depending on the soil condition, ventilation efficiency, relative air humidity cellars and cellars belong to damp and especially damp rooms, and according to the degree of danger of electric shock - to especially dangerous rooms.
Increased requirements are imposed on electrical wiring in cellars and basements, namely:
The mains voltage should not exceed 42 V. For this, step-down transformers should be used;
Perform electrical wiring directly on the base on insulators and rollers with insulated protected wires or cables. For hidden wiring, it is forbidden to use steel pipes with a wall thickness of 2 mm or less;
Lamps of hermetic design should be used to prevent moisture from entering the electric cartridge;
The switch should be located outside the cellar and basement.
Wiring in the attic
Attic space called a room above the top floor of a building, the ceiling of which is the roof of the building and which has load-bearing structures (roof, truss, rafters, beams, etc.) made of combustible materials.
Wiring in the attic perform mainly for laying inputs from overhead lines into the building to the terminals of the apartment shield. In country houses, attic lighting is not required.
Installation of any electrical wiring, apart from laying inputs, in attics with structures made of combustible materials, it is better not to perform.
Attic spaces have a number of features. They are subject to temperature fluctuations, as a rule, are dusty, and have an increased fire hazard. Accidental damage to electrical wiring can lead to ignition of wooden structures and further to a fire. Therefore, increased requirements are imposed on electrical wiring in attics.
The following electrical wiring can be used in attic rooms:
- open- wires and cables laid in steel pipes, as well as protected wires and cables in sheaths of fireproof and slow-burning materials at any height;
- unprotected insulated solid wires on rollers and insulators at a height of at least 2.5 m from the floor.
At a height of less than 2.5 m they are protected from touch and mechanical damage. The distance between the attachment points of the rollers should be no more than 60 mm, insulators - no more than 1000 mm, between the wires - no less than 50 mm. The height of the rollers must be at least 30 mm. The rollers are installed on boards hemmed to the rafters.
Concealed wiring It is carried out in walls and ceilings made of non-combustible materials at any height.
Exposed electrical wiring in attic rooms they are carried out with wires and cables with copper conductors. Wires and cables with aluminum conductors can be laid in buildings with fireproof floors, provided they are laid in steel pipes or hidden in fireproof walls and ceilings. Transit lines in attics up to 5 m long are allowed to be made with wires with aluminum conductors.
When laying steel pipes it is necessary to exclude the penetration of dust into pipes and junction boxes, for which sealed threaded connections are used. Pipes can only be connected with threaded couplings without seals in dry and dust-free attics.
Pipes are laid with a slope so that moisture cannot accumulate in them.
Connections and branches of copper or aluminum conductors of wires and cables carried out in metal junction (branch) boxes by welding, crimping or using clamps corresponding to the material, cross section and number of cores.
Branches from lines laid in the attic, to electrical receivers installed outside the attics, it is allowed provided that both the line and the branches are laid openly in steel pipes. Hidden in fireproof walls and ceilings.
Breaking devices in circuits that feed lamps located directly in attics, they are installed outside the attics, for example, at the entrance to the attic.
Steel pipes, metal luminaire housings and other metal structures of electrical wiring must be zeroed.
ATTENTION! It is forbidden to lay any non-metallic pipes in attics.