Wiring in the house with his own hands

Any owner of a private house, sooner or later, but exactly - at least once in his life faced with the need to repair, replace or create "from scratch" wiring.Of course, with any repairs or construction and want to save some of the work to take on, but what concerns electrical wiring without the basic knowledge and skills in this matter is still not enough.Electricians - a special caste of masters, on which depends our comfortable, safe and long life.As they say in the joke: "Coda God said" Let there be light- wiring has already been installed. "And in a dispute about what is the oldest profession - all the arguments are on the side of the electricians and not agents or other representatives of the oldest professions.

Wiring in the house with his own hands is quite possible, but only on condition that the owner understands the principles of wiring, trust regulations and ready to plunge himself in the difficult, but at the same time a fascinating process.Therefore, the authors of the collective offers even finish reading this article until the end and if you do not understand, then it makes sense to refer to specialists (about their identification on a good category - poor will be discussed later).And if all is clear, then why not?

small philosophical digression on electricity

electrical energy began to enter into human life only in the second half of the XIX century, and in a relatively short time (less than 200 years), it is "slid" to the second, third and other plans of their competitors.Without electricity the existence of human civilization in its present form is simply unthinkable.Everything that used to do hands - is now entrusted to the very clever devices powered by electricity.While we sleep, they wash, wash dishes, the water is heated, monitor and carry out our security are other important functions.Installed power of human habitation is growing every year.Compared to 1950 the world's electricity production increased by more than 25 times, and this trend will continue in the future.

What is the wonderfulness of electricity?What it has advantages?

• first advantage - easily transfer electrical energy, do not need to build pipelines, pumping hydrocarbons and enough to build cheaper lines.
• second advantage - electricity is very easy to manage.
• third advantage - electricity can be easily converted to any type of energy: light, mechanical, thermal.

main disadvantage of electricity is that it is expensive, as 67% of it is produced by the combustion of hydrocarbons in the thermal power plant, only 19% hydro and insignificant 14% at the plant.That is why very little electricity is used for heating, it is much cheaper to burn hydrocarbons in the gas and solid fuel boilers.

What is the cable and wire that is?

For the average man in the street, we are in the majority and are, there is no difference between the cable and wire.But in organizing the wiring should deal with this issue in more detail.

• Wire - is solid or stranded conductors, which may be insulated or to be without it (for example, power lines).Wires are mainly designed for indoor installation.One species of the wires are cords, which always consist of stranded cores and therefore having increased flexibility.Cords used to connect various home appliances, as well as for the manufacture of extension cords.
• Cable is a system of insulated wires with a common protective sheath to protect it from adverse environmental factors.The cables may be routed depending on the destination, in the ground, under water, inside the building structures.They have much better protection and isolation, rather than a wire, and it is therefore recommended for wiring.

authors will not distract the reader's attention to the variety of wire and cable, their labeling and other things that would be interested layman.It will be said only about that which wires and cables must be used in the arrangement of the wiring, and a cross-sectional area they should be.

To connect the electrical opening of private homes are now using self-supporting insulated wires - STS, which replaced the non-insulated overhead wires.Besides the fact that these wires are aluminum phase insulated conductors, they are fitted with steel or aluminum, in combination with the neutral wire, which still performs the function of a carrier.For their installation, including air are not required to provide further special cables or hangers, wire protected polyethylene insulation, not afraid of any changes in temperature or UV radiation.In addition, the use of these wires or eliminates, or greatly complicates the unauthorized connection to steal electricity.To do this, power supply organizations mounted guards with electrical counters on the street and connect one piece of insulated wires, and a place to connect the wires to the circuit breaker is sealed, which prevents free access.All of these actions - the prerogative of the utility companies and we as consumers of electricity it has little concern.Here is what is going on an introductory panel with a counter, that comes into the house and there is distributed - should care the most, because it is our area of ​​responsibility.

Aluminium vs copper

in electrical wires and cables in two major metal used as a conductor: aluminum and copper.These metals have good conductivity 1 kilometer of copper wire, 1 mm2 has a resistance of 17.5 ohms, and aluminum - 28.5 ohms.But the physical and chemical properties of these two metals differ greatly, and not in favor of aluminum.

• and copper, and aluminum is a reactive metal that is easily oxidized in air.However, a film of aluminum oxide that is inevitably formed on the surface thereof, has much poorer conductivity than the metal and a film of copper oxide.That is, in place of the aluminum contact area is always a high electrical resistance.

• mechanical properties of aluminum wire is much worse than copper.It is enough to bend a few times - to straighten the wire, so that it broke, at the same time, copper conductor can withstand a very large number of bends.That is why the flexible wires and cords are used only copper stranded conductors.
• in electrical engineering there is such a thing as the current density, which reflects a current can flow into 1 mm2 cross sectional area of ​​the wire or cable, with a current should not lead to excessive heat, which can cause a fire of both the wires and nearbyitems.At a current density of copper can be from 6 Amperes (A) to the hidden wiring and up to 10 A for open wiring.Naturally, the design of the wiring section is selected with a margin not to "chase" the cable in such modes, which will be at the limit of its capacity.At a current density of aluminum per 1 mm2 to 1.5 times less than that of copper, and is 4 A flush to 6 and A to open.Again aluminum copper loses!
• Aluminium has one unpleasant for wiring the physical property.it is easily compressed under the influence of mechanical stress, or electricians say - "flows".After some time, contact weakens, the connection begins to spark, and the formation of the gap can ignite an electric arc at a temperature of several thousand degrees.That is why all the switching point where used aluminum wire should be tightened from time to time or not use spring terminals, which provide constant contact with the right effort.

only advantage aluminum wiring - is its lower cost.Not without reason at the time of mass housing construction in the USSR, it is widely used aluminum wire.Firstly, the industry can not provide all the needs it in the copper wiring, and secondly, the use of aluminum greatly reduced the cost of construction.Readers of our portal we intend to give one piece of advice: if you have a wiring of aluminum, then consider that you have no wires!Urgent and at the first opportunity redo and replace it with a copper!The use of aluminum is only justified in power cables, but let it be the area of ​​responsibility is not yours, and organizations dealing with electricity.Do you want to live comfortably and sleep peacefully - do copper wiring.Let more expensive, but safer, more durable and more reasonable.By the way, in the United States (the country with the most developed economies) use aluminum wires in the power supply of houses and apartments are not at all considered.Hard, but in terms of the engineering science - is absolutely the right approach.

About Contact copper and aluminum

If it was possible to keep statistics on the causes of fires due to the wiring, then one of the leaders would have taken an incorrect contact of copper with aluminum.The main scourge - a twisted copper and aluminum wires.What is dangerous is the connection?

• Firstly, copper and aluminum by passing electric current through them will be heated, and they have very different thermal expansion.In other words - contact place will be subject to significant mechanical stress, which weakens the contact.
• Secondly, different electrochemical properties of copper and aluminum always result in the formation on their surfaces oxide films with conductivity of alumina is much less than copper oxide, and is also a violation contact.
• Finally, if the contact of copper and aluminum wire is inevitable, it should be done only through a "mediator" - a steel clamp.And the best way out of this situation is the use of spring clips from a reputable manufacturer - company Wago (they will be a separate item in our article).Apart from the fact that products of this firm spring contacts are used, which ensure a good constancy of contact, they still have a special paste, and which prevents the oxidation of aluminum and copper.

And best of all to take a simple rule - no contact between copper and aluminum.If it exists, then let him meet others, but not you.And all of these contacts it's better to take place outside the walls of your home.

Monozhilny vs stranded wire

disputes very often arise as to which cable or wire is laid in the organization of the wiring in the house: monozhilny or stranded.Here are a few statements that will help you understand the advantages and disadvantages of both approaches.

• for fixed wiring definitely have to choose a single cable, so it has a higher mechanical strength.
• contact area with stranded wire and single-wire differs significantly.Therefore, larger stranded wire exposed to atmospheric oxygen and humidity.Because of this oxide film are formed, breaking the contact.
• The use of flexible stranded conductors is justified only when it is required to connect the lamps, which periodically need to change the lamp, while the flexibility of the wire will be useful.
• All connections stranded wires should be made only after they dressed and crimp pliers special tip that will shape the end of the core wire for subsequent connections with electric or other wires.Why?Why?Why?