The following requirements are imposed on materials of this type: minimum value of electrical resistivity; fairly high mechanical properties (mainly tensile strength and elongation at break); the ability to be easily processed, which is necessary for the manufacture of wires of small and medium sections; the ability to form contacts with low contact resistance when soldering, welding and other methods of connecting wires; corrosion resistance.
Copper
Advantages of copper:
1. Low resistivity (only silver has less).
2. Sufficiently high mechanical strength (compared to Aℓ).
3. Corrosion resistance (compared to Fe).
4. Processes well (receives thin wire and sheet).
5. Easy to solder and weld.
Disadvantages of copper:
1. It is rare and therefore expensive.
2. In some cases, insufficient mechanical strength.
3. Oxidizes in air (copper wires in air near the sea are subject to increased corrosion due to the action of salts contained in the air).
Aluminum
Aluminum is the second most important (after copper) conductor material.
Advantages of aluminum:
1. Aluminum is 3.5 times lighter than copper. If wires of equal resistance are made from aluminum and copper, then the Al wire will have a cross-section 1.63 times larger, but will still be 2 times lighter than copper.
2. Widely distributed in nature (its content in earth's crust not less than 7.5%).
3. Aluminum is covered with a thin oxide film, which protects it from further corrosion (it is not affected by water vapor, fresh and sea water).
4. Aluminum is well processed; thin foil (6÷7 microns) can be obtained from it.
Disadvantages of aluminum:
1. Aluminum has low mechanical strength (it is not possible to obtain thin wire from it).
2. Due to the dense oxide film, aluminum cannot be soldered in the usual way; this requires special solders and ultrasonic soldering irons.
3. The resistivity of aluminum is 1.63 times greater than that of copper.
4. At the point of contact of Al with other metals, a large contact resistance and increased corrosion occurs as a galvanic couple occurs. Electrochemical corrosion worsens in the presence of moisture.
Aluminum is used in the following products:
− power transmission line wires (aluminum and steel-aluminium, where the mechanical load is carried by steel);
− cable cores;
− cable sheaths to replace lead (moisture protection);
− capacitor plates;
− windings of some transformers, etc.
Iron (steel)
As the cheapest and available metal, which has high mechanical strength, is of great interest for use as a conductor material.
Advantages of iron:
1. Cheap and widely available.
2. High mechanical strength.
3. Solders well (worse than copper, but better than aluminum).
Iron deficiencies:
1. The resistivity is 6-7 times that of copper.
2. With alternating current, a surface effect occurs, only part of the cross-section is used, so the resistance increases.
3. With alternating current, hysteresis losses occur.
4. They have low resistance to corrosion, especially in conditions high humidity(coated with zinc for protection).
Iron has found application:
− power line wires at low voltage (the current is low, the cross-section is determined by mechanical strength);
− tram rails, railways, metro;
− steel-aluminum wires.
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Why is copper wiring better than aluminum?
Aluminum electrical wiring was used in the Soviet Union for many decades. Aluminum - relatively cheap material, having good conductivity and chemical resistance. In addition, it is very lightweight, which makes the work of workers much easier. This type of wiring lasts a long time and is reliable.
But with the increase in the number of electrical appliances, the load on electrical wiring has increased several times. It is no longer advisable to use aluminum wiring.
Today with electric installation work ah use copper wiring.
Reasons Why is copper wiring better than aluminum?. some:
Firstly, copper has a lower resistivity compared to aluminum and is capable of withstanding larger loads with a smaller cross-section. At modern levels electricity consumption, in ordinary apartment I'd have to pull aluminum wire by 4 or even 6 mm square. while for copper 2.5 or 4 mm square is enough.
Secondly, copper wiring is more flexible.
Copper or aluminum wire - which is better?
Previously, they installed one socket at a time. Nowadays they even install 5 or more sockets in one place. This is due to the huge number of electrical appliances in modern house. In this case, the sockets are connected with a cable, which is quite difficult to do with aluminum wire. Modern chandeliers also have copper inputs
ends, and they cannot be connected to aluminum.
Thirdly, aluminum is prone to oxidation. A film of high resistance appears on its surface. As a result, the contacts heat up and possibly burn out. Over time, aluminum becomes very brittle. Sometimes, after disassembling the old electrical box for repairs, and when you take out the wires, you can see how they simply crumble in your hands.
Moreover, although aluminum wiring laid in the USSR has been in service for 30 years, modern aluminum is no longer the same as it used to be. Today's aluminum wire can be broken during installation, especially Chinese wire. It’s hard to even imagine what will happen to him in ten years.
There are only two cases when it is better to use aluminum wiring:
Aluminum wires are used if you are going to partially replace the wiring in the apartment, and the old wiring is also aluminum. In this case, laying copper wires is impractical, since copper and aluminum should not have direct contact; terminal blocks must be used.
Aluminum is widely used for cables with a cross-section of more than 16 mm square. This makes electrical installation cheaper, while the negative properties of aluminum with such sections are less noticeable.
In all other cases, it is better to use copper wiring.
Source: donelektrik.at.ua
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Only two metals - copper and aluminum - are widely used as conductors of electric current. Their use in this capacity is determined by a complex physical properties the metals themselves and their prices.
Physical basis of the flow of electric current in conductors
As is known from physics, electric current- this is the ordered movement of electrical charges in a conductor, under the influence of forces electric field. When electric charges move in a conductor, they are subject to resistance, which is assessed by the value of electrical resistance and which is measured in ohms (Ohm).
Electrical resistance for cylindrical conductors is determined by the formula r=ρ*l/s, where r is electrical resistance conductor, Ohm, ρ - specific electrical resistance of the conductor material, Ohm*mm2/m, l - length of the conductor, m, s - cross-sectional area of the conductor, mm2
Therefore, in electrical engineering, materials with low resistivity (copper, aluminum, steel) are used to make wires.
For example: Copper resistivity - 0.0175 ohm*mm2/m, aluminum resistivity - 0.0294 ohm*mm2/m
Sometimes, instead of electrical resistance r, the inverse value is used - conductivity g = 1/r, and instead of specific resistance - specific conductivity γ = 1/ρ. Electrical conductivity is measured in siemens (Sm).
When electric charges move in a conductor, electrical resistance causes the conductor to heat up. This heating is harmful and, when operating the conductor, must be limited, taking into account the physical properties of the conductor and the insulation class.
The steady-state temperature of the current-carrying conductor depends on the current density, which is determined by the formula: δ=I/s, where δ is the current density, a/mm2, I is the current value, and s is the cross-sectional area of the conductor, mm2
What is more profitable to use as electrical wires - copper or aluminum?
When comparing the growth trends in the cost of aluminum and copper during the 20th and early 21st centuries, it is obvious that the cost of aluminum is growing more slowly than copper. This difference is especially visible at the beginning of the twenty-first century.
Articles on the topic - Electrical, wiring
Since 2006, the price of copper on the London Metal Exchange has reached $8,500/t, while aluminum has reached $2,500/t.
This is due to the improvement and increase in aluminum production, with accessible and inexpensive raw materials, which, in the cost of the final product, amounts to 25%.
For copper the situation is different. Copper ore reserves are deteriorating, the copper ore content is falling, new deposits are poor in metal and are more difficult to extract. In addition, these deposits are geographically more difficult to access. Therefore, the cost of raw materials in the cost of the final product is more than 50% and is still growing.
These trends are not changing, as are comparative price dynamics, and changes are not expected. All this speaks in favor of using aluminum.
Scientific discovery of superconductivity and its industrial application are still unattainable in world practice. In light of the fact that electrical conductivity aluminum is lower than that of copper, the cross-section of the aluminum wire and, therefore, its volume must be greater than that of copper, and the diameter of the aluminum wire, for the same current density, must be 25% greater than that of copper.
However, the increase in volume, and therefore weight, of aluminum wire is offset by the low density of the metal (2.7 t/m3 - aluminum, 8.9 t/m3 - copper). Therefore, the mass of an aluminum wire, for the same current density, is three times less than that of copper.
However, there is no gain in weight when using aluminum wire instead of copper, due to the requirements of SNIP. For example, the mass of copper in laid wires and cables, in panels of modern three-room apartment, is 10 kg. Weight of a three-core cable 1000 meters long VVG cable(copper) with a cross-section of 1.5 mm2 is 93 kg, and the weight of the equivalent AVVG cable (aluminum) with a cross-section of 2.5 mm2 is 101 kg. The benefit from using aluminum wires is due to much lower prices for aluminum.
At current prices, the use of aluminum wires is several times more profitable than copper wires!
For high voltage lines Aluminum has also been used for overhead cable systems for a long time. But in insulated wires, an increase in the core diameter requires an increase in cable consumption. PVC plastic that, the price of which ($1,800/ton) is close to the price of aluminum. The thinner the wire strand, the higher the comparative costs of electrical insulation, and the lower the benefits of switching from copper to aluminum. However, at current prices, the savings are still significant!
Designers, architects, and electricians must overcome their bias against the use of aluminum wires in new construction. This will allow the use of profitable, but labor-intensive aluminum for wiring in panels and in connections to external load points (sockets and switches), which will provide significant savings.
Aluminum winding wires can be used with noticeable benefit in the production of low-power transformers, electric motors and other electrical machines.
All this will determine the huge demand for aluminum on the world market and the use of the “winged metal” on earth.
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Why is copper cable better than aluminum?
There are several factors that force you to choose a copper power cable instead of an aluminum cable:
- Copper cable has better conductivity compared to aluminum. With the same cross-sectional area of the cable core, copper can withstand loads significantly greater than aluminum.
Which wiring material is better, copper or aluminum?
For example, with a cross-sectional area of 10 mm2, an aluminum conductor can withstand an electric current of up to 50A, and a copper conductor of the same cross-section can withstand a current of up to 70A. That is, if it is necessary to replace an aluminum cable along a ready-made main line and the thickness of the cable is limited, and the expected load has increased, then laying a copper cable instead of aluminum will allow, with the same cable dimensions, to increase the permissible load.
- Copper cable has greater chemical resistance compared to aluminum. Copper is a noble (inert) metal and does not react chemically with most substances. And aluminum is exposed to chemical attack, as a result of which it is destroyed.
- Copper cable has greater mechanical strength compared to aluminum. This can be observed at the connection points of aluminum cables in home wiring. In the area of the terminals, the aluminum core is always very crushed and often destroyed, which never happens with the copper core.
There are several other factors that make copper cable more preferable, but it would take a very long time to list and describe all of them, since they are no longer so obvious. And the only one positive thing Aluminum cable is served by its low price compared to copper.
Aluminum wiring
We are often asked the question: “What to do if the apartment has aluminum wiring?” In this article I will try to answer this question.
Aluminum wiring or copper?
According to the “Rules for Electrical Installations”, aluminum wiring can be used in temporary buildings and structures, the service life does not exceed two years. In other cases, electrical wiring should be done with copper wires.
If we turn to statistical data, fires arising from faults in electrical wiring in electrical installations using aluminum wires occur 60% more often than in electrical installations using copper wires.
Additionally, I would like to note such a point as the design load. The appearance of powerful household appliances in everyday life causes overloads of electrical wiring. If the wires in the apartment are made of aluminum with a cross-section of 2.5 sq. mm, then this wiring is designed for a total group line consumption of no more than 2.5 kW. Therefore, if you turn on a 2.7 kW kettle, and the lights are still on, the TV is on, etc., then we can definitely say that the wiring is overloaded. And this leads to its accelerated wear and tear.
Service life of aluminum and copper wiring
As for the service life of wires, for aluminum wires the service life is approximately 10-15 years, for copper wires - 20-30. But you should also pay attention to the operating conditions of the wires. If wires are systematically overloaded, if the insulation is exposed to aggressive conditions external environment(rain, heat, frost, ultraviolet rays) then the service life is reduced.
Connection of copper and aluminum wiring
The main problem with connecting aluminum and copper wires is the formation of a galvanic couple by these metals. Which leads to oxidation of the junction of the wires. Therefore, it is necessary to exclude direct contact of these metals with each other. Connecting copper and aluminum wires can be done in three ways:
- using special Wago terminals for connecting aluminum wires. The connections in these terminals are protected from oxidation with a special paste, which eliminates contact of aluminum with air. Direct contact of copper with aluminum is also excluded.
- screw connection. It is imperative to exclude direct contact between copper and aluminum, as well as install special Grover washers, because This washer ensures constant pressure on the wires, otherwise the screw connection may deteriorate over time.
- sleeves for connecting copper with aluminum, this method requires special equipment, and sleeves for such a connection cannot be bought in every store.
How to move aluminum wiring sockets
When moving sockets, you can use both aluminum and copper wires.
ELECTRICAL CONDUCTIVITY
The technology for carrying out the work is similar to that in the article moving sockets and switches. If the wire does not come from the distribution box, then place distribution boxes, which will allow access to connections for inspection or repair. Connections are made using special connectors described above.
I hope that in this article I was able to answer all your questions. If you need oral advice, as well as on issues related to replacing aluminum wiring, you can contact me or my partners by phone in St. Petersburg +7 (921) 883 - 75 - 46.
And again repairs, and again dilapidated walls, putty and the desire to get closer to your cherished dream. One of them is to ensure that copper wires for wiring finally take their rightful place, instead of the old aluminum ones.
Copper wires - new requirements for high-quality electrical wiring
Which wires would be better to choose: copper or aluminum? This question, first of all, can be addressed to your electrician, although we can already assume that his answer will be in favor of copper ones.
And all because copper wiring is more preferable in conditions of the all-consuming “invasion” of modern electrical appliances. If you still don’t understand at all where the wires in your apartment come from and where they go, and it’s not at all clear why wiring is needed, then we can advise you not to bother studying physics texts at all and give everything into the hands of an electrician - both the right to choose and materials, and, of course, money for paying for his services.
Without the involvement of specialists and with superficial knowledge of the material, installing wiring “from scratch” will be not just difficult, but extremely difficult. But for the most persistent ones we are organizing an educational program. So, the wires (those general purpose) can be made of either copper or aluminum. Considering that insulation is one of the most important issues in electrical wiring, the wires are protected by materials made of PVC plastic, as well as rubber or polyethylene.
Aluminum and copper wire are significantly different from each other - the first costs much less and suffers from a number of disadvantages, the second is considered less fragile and has lower electrical resistance (compared to its aluminum counterpart). Well, of course the price is higher. Aluminum wire has increased fragility, as well as problems with soldering connections.
Add to this the high electrical resistance, and it becomes clear why such wires are inferior to copper ones, and your electrician doesn’t want to hear anything about aluminum. Both wires can be vinyl insulated, this is allowed by regulations. Previously, it was aluminum wires that were used in apartments; now the owners of such apartments have to decide whether to completely change the wiring to a new one or patch the old one using the same materials that were previously available.
Copper Wiring and Load Capacity
Residents of new buildings have already appreciated the advantages of copper wiring. In apartments built in the last decade, wiring takes into account new requirements and recommendations. So those who are just moving into new apartments do not need to rack their brains over whether their wiring will withstand a large army of household appliances, most likely numbering well over a dozen, or not. By the way, for general information, a copper wire can withstand an active load of 5 kW, while aluminum wire can withstand only 3 kW.
High-quality electrical installation will, of course, take a lot of time and money, but thanks the right approach, your electrical wiring will not immediately burn out due to increased loads and will not cause harm to you and household appliances. It’s better to solve the issues with laying the right wire once than to reproach yourself later for not taking into account some important details. So the right decision is to choose a copper sample that has both high electrical conductivity and ductility. Only, despite everything positive qualities mentioned above, don’t be lazy and use a calculator to calculate what the total load on the network will be when using your electrical appliances (do the breakdown for different rooms).
It is better for you to lay flat wires directly in the walls, which allows you to avoid breaking deep into the walls. If you need to lay a round wire, then when passing it through the installation pipes (corrugated), you will have to strain yourself so as not to turn the walls. Moreover, the usual diameter of the corrugation (pipe) is approximately from 11 to 23 mm. Yes, and do not forget that the wires will have to be laid either horizontally or vertically (and not as you please), they will be connected in special installation boxes, and they will have to be covered with a layer of plaster on top.
Let's start with simple ones, but important advice, which can help you reconsider your view of electrical wiring - everything is not as scary as you might initially think. So we read, think and remember.
- For lighting in your house or apartment, it is better to use copper wire with a cross-section of 1.5 mm2. In this case, it is better to form several groups for connecting devices - for rooms, kitchen and corridor with bathroom.
- For sockets, it is better to take copper wire with a cross section of 2.5 mm 2. For powerful devices such as washing machines or electric stoves, it is better to purchase samples by first looking at the instructions for the purchased product.
- The rooms must have at least one socket (double) for every 5 m2. . There are 5 sockets in the kitchen (with mandatory grounding). In the bathroom it is better to provide (due to high humidity) two sockets with moisture protection. There are several near the TV (for using different devices).
- You can place sockets in rooms half a meter from the floor, in the kitchen above the meter mark (it’s easier to connect household appliances at countertop level), but in the bathroom away from the bathtub or yours (caution due to humidity and the possibility of splashes).
- A grounding contact is not only necessary, but also mandatory. Don't try to change what has been created and widely used in security for years. There is no need for consultation here - this point is accepted, not discussed.
- When connecting a new grounding system, it is better to purchase and use a three-core cable. This will allow you not to be afraid that you may get an electric shock, or that there will be an emergency fire in the house.
- Please note that equipment with higher than usual power (from 2 kW and above) can only be connected to separate circuits (dedicated lines). One such circuit can be for a maximum of 10 sockets or two dozen lighting fixtures.
- Calculate the maximum load taking into account simultaneously connected and operating household devices. Please note that the number of your electrical appliances may grow “unnoticed by you”.
- The cable sold in the store, as a rule, has markings - black or brown (phase wire), light blue (neutral), yellow-green (grounding marking). The phase wire is always located on the left side of the socket.
Which is better - copper or aluminum wiring? This question is often raised among specialists and ordinary people planning to replace old wires in a house, apartment or office. But in order to make the right decision, it is important to know the advantages and disadvantages, operating rules, as well as the main differences between copper and aluminum switching.
Pros and cons
Aluminum wiring has the following advantages:
- Small mass. This feature is important when installing power lines, the length of which can reach tens or even hundreds of kilometers.
- Affordability. When choosing a material for wiring, many are guided by the cost of the metal. Aluminum has a correspondingly smaller value, which explains more low price products made from this metal.
- Resistance to oxidative processes (relevant in the absence of contact with open air).
- Availability of protective film. During operation, a thin coating forms on aluminum wiring, protecting the metal from oxidative processes.
Aluminum also has a number of disadvantages that you need to be aware of:
- High metal resistivity and tendency to heat. For this reason, it is not allowed to use wires smaller than 16 sq. mm (taking into account PUE requirements, 7th edition).
- Loosening of contact connections due to frequent heating when passing a heavy load and subsequent cooling.
- The film that appears on an aluminum wire upon contact with air has poor current conductivity, which creates additional problems at the junction points of cable products.
- Fragility. Aluminum wires break easily, which is especially important when the metal frequently overheats. In practice, the service life of aluminum wiring does not exceed 30 years, after which it must be replaced.
Rules for connecting copper and aluminum
There are situations when you need to replace only part of the wiring or add (move) several outlets in the apartment. In such a situation, the question arises. To avoid increased heating in places where copper and aluminum wiring are combined, it is worth using the following switching methods:
![](https://i1.wp.com/yaelectrik.ru/wp-content/uploads/2017/03/04-7.jpg)
The considered connection methods can be used to combine wires made of various metals (not only copper and aluminum). This design guarantees a high level of safety and the ability to avoid potentially dangerous twisting. But it is worth remembering the importance of periodic checking and broaching bolted connections and terminal blocks, because they tend to weaken.
Which wiring material is best?
Now let's look in more detail which wire is better, copper or aluminum. In this regard, many stereotypes and misconceptions have emerged, which we will discuss below:
- Durability. It is believed that the lifespan of copper wire is longer than aluminum. This is a misconception. If you look at a special reference book, you can make sure that the service life of cables made of both types of metal is identical. For products with single insulation it is 15 years, and for products with double insulation - 30.
- Tendency to oxidation. When using an aluminum cable, it is worth remembering its tendency to oxidative processes. Back in school, we were told that Al (aluminum) is a metal that actively interacts with oxygen, which is why a thin film appears on its surface. The latter protects the metal from further decay, but impairs its conductivity. If the wire is isolated from the environment, the risk of oxidation processes is minimized. The best option- use of special terminal blocks with conductive paste. The peculiarity of the latter is to improve the quality of the contact connection between two wires and remove the oxide film from the metal. In addition, a special lubricant prevents aluminum from coming into contact with the surrounding air.
- Strength. Copper wiring is considered more durable and can withstand repeated bending. GOST states that a wire made of copper must withstand 80 kinks, and one made of aluminum - 12. If the wiring runs in the wall, floor, or is hidden under the ceiling, this feature is not so important.
- Price. The price of aluminum wire is 3-4 times lower. But when choosing, it is important to remember that a copper wire with a cross-section of 2.5 sq. mm is designed for a current of 27 Amperes. If you give preference to aluminum wiring, the thickness of the wire should be 4 square meters. mm ( rated current 28 Ampere).
- Resistance. When deciding whether to choose aluminum or copper wires, it is worth considering different resistivities. For copper, this parameter is about 0.018 Ohm*sq.mm/m, and for aluminum - 0.028. But it is worth considering that the total resistance (R) of the conductor depends not only on the mentioned parameter, but also on the length and area of the conductor. If we take into account that aluminum wires of a larger cross-section are used for the same load, the final R of copper and aluminum products will be approximately identical. The greatest resistance occurs at the joints, but if you follow the tips discussed above, you don’t have to worry about this.
- Ease of installation. It is believed that the connection of aluminum wires is more difficult task. This is only relevant for the usual connection of wiring, by twisting. In the case of using end caps, terminal blocks or bolts, this problem disappears.
The situation that implies deserves special attention. When copper and aluminum combine at the point of contact, various processes occur, due to which the resistance increases. As a result, the junction of the two wires overheats, the insulation is destroyed and the risk of fire increases.
The feature discussed above is characteristic of all metals having different resistivities. In addition, many manufacturers do not use “pure” metals, but their alloys, which also leads to a change in the resistance parameter. To avoid problems in the future, it is better to connect the wires correctly and avoid twisting them.
In conclusion, here are a few tips that should be taken into account when organizing wiring:
- In case independent design wiring in a house or apartment, it is better to choose copper wires. With a smaller cross-section, they can withstand greater currents and are more resistant to frequent bending. An equally important point is volume. Copper wires are compact, which simplifies the process of creating grooves. For example, when connecting a receiver with a power of 7-8 kW, the aluminum wire should have a cross-section of about 8 mm. The cable has three cores plus a braid. As a result, the total diameter is about 1.5 centimeters. For comparison, copper can have a cross-section of 4 sq. mm, and the overall diameter is no more than a centimeter.
- When installing a socket, a three-wire cable with a ground wire must be used. The distance of the socket from the floor is 30 cm. When organizing a lighting circuit, it is allowed to use cables with two cores (grounding is not needed here).
- It is forbidden to hang the entire load on one pair of wires (especially if they are aluminum). The best option is to divide the circuit into several lines. For example, a bathroom is powered through one machine, lighting through another, a kitchen through a third, and so on. The wire cross-section for the kitchen and bathroom should be 4 or 6 sq. mm, and for the lighting circuit - 1.5 or 2.5 mm.
The most difficult situation is in old apartments where aluminum wires are installed, which have outlived their useful life and require replacement. Wiring with a cross-section of 2.5 sq. mm can withstand a load of no more than 20 Amps, which is not enough for modern electrical receivers. In addition, the insulation of the wires loses its elasticity over time and gradually deteriorates. In such a situation, the only solution is to completely replace the wiring with copper wires.
For more information on why it is worth replacing aluminum wiring with copper in an old house, watch this video:
Results
Which wire is better? From the position performance qualities copper is more preferred. Based on cost, aluminum wires are cheaper. And here it is important to make a decision - to save on your safety or not.
It is impossible to imagine a house or apartment without electricity in our age; light comes to all apartments and houses. To determine which wiring is better, copper or aluminum, it is necessary to consider the characteristics of the two materials and conduct a comparative analysis.
Aluminum wiring
This type of wiring has become widespread in residential buildings and apartments throughout the country back in Soviet times. You can still find aluminum today, in any house older than 15-20 years. This was due to such alloy parameters as:
- light weight;
- cheapness.
Since aluminum weighs much less than copper, it is more often used when laying power lines, which reduces the load on the supports and, accordingly, saves on their manufacture and installation. According to the installation instructions new network Aluminum cables with a cross section of less than 16 mm 2 are not used. Don't discount the cheapness either, since copper is more expensive.
Cons
However, even high-quality aluminum wire has more disadvantages than advantages. Negative points include:
- lower electrical conductivity than copper (2 times difference);
- the ability to oxidize upon contact with air (as a result of oxidation, a layer is formed on the surface of the wire that does not conduct electric current, which reduces the useful cross-section and increases resistance);
- shorter service life (20-25 years, after which the likelihood of a fire increases sharply due to oxidation and subsequent heating of the contacts);
- weak mechanical strength (after several bends, the aluminum cable breaks easily);
- complexity of installation (in this case, it will be necessary to ensure the necessary conductivity by choosing cables with a larger cross-section, which are extremely inconvenient to work with. Such cables are produced only as single-core cables).
Advice! You can check the quality of aluminum for fracture; to do this, when purchasing in a store, try bending the wire 4-6 times; if its surface quickly becomes covered with cracks, then the wire is fragile and will be difficult to work with. It is clear that it is better to refuse such a product.
Copper wiring
When buying or building a house or apartment, it is advisable to use this type of wiring. However, keep in mind that by replacing the wiring in the apartment you have not yet received a reliable network that can withstand heavy loads. Do not forget that the input cable from the staircase panel to the apartment in old apartments is always made of aluminum. This section should be replaced, because its conductivity is now weak point new network.
Advantages of copper wiring
Comparing the parameters presented below with the parameters of aluminum will allow you to make right choice in the future. Copper, as a material for electrical wiring, has a number of advantages, which include:
- good conductivity (even after oxidation, the film on the surface does not interfere with the passage of electric current);
- service life reaches 50 years;
- high mechanical strength (the core can easily withstand bending and twisting up to 10-15 times);
- ease of installation (the industry produces several types of wires with different parameters and cores that are convenient to work with).
There is probably only one downside to a copper home network - its price, however, when it is necessary to perform high-quality wiring, give preference to this material.
IN construction stores You can purchase wires made of zinc alloys coated with copper plating. They are cheaper than copper ones, however, the characteristics of the materials are inferior to wires made of pure copper.
If there is a shortage of funds, it is better to perform combined wiring, power the socket group separately with copper wires designed for high current, and the lighting circuits with aluminum. However, keep in mind that the connection between aluminum and copper is made only through special clamps or connecting blocks, which prevent direct contact between copper and aluminum, which causes severe oxidation of the latter. Due to oxidation of the joint, the resistivity of the contact increases, heating and eventually burning occurs.
Having examined the characteristics, it is easy to come to the conclusion that it is better to use copper for installation work, however, if necessary, you can make the network from aluminum, but you will have to monitor it more carefully. It is necessary to choose one or another type of wiring taking into account electrical safety requirements, because this determines how long the network will last without the need for specialist intervention.
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