Copper is always used in our wiring systems, is copper a Conductor of Electricity? If so, why another conductor cannot replace it? To understand it, firstly you need to know about copper. Copper is an element of periodic table (with A = 63 and Z = 29) which is present in animal bodies and plays a key role in metabolism. Although it is not a component of hemoglobin, but is required in synthesis of hemoglobin. Copper is a metal which is used in versatile fields, due to its numerous applications. After silver, copper is the mostly used conductor in commercial field due to its excellent electrical conductivity.
Now a day’s copper and its alloys are even being used in power transmission lines, spark plugs, copper utensils, electrical wiring, electrodes, coins, metal work, electroplating, dyeing, roofing and even more. It is also used (as powder form) as pigment in paints. The reason to be able for such a wide range of applications, is its versatile properties; like good strength, high conductivity, machinability, corrosion resistance. Chief use of copper is found in alloys like bronze, brass, german silver and monel metal.
Copper is being used in electrical wiring since the invention of electromagnet. Further demand for copper wires as electric conductor was created after invention of telephone. Cu wires are used in telecommunications, electronics, power generation various types of electrical equipment. Cu and its alloys are even used in making electric contacts.
Types of Cu wires
Usually, copper wires are classified into 2 types which are given as:
Solid copper wire: It consists of one strand of copper metal wire, which is sometimes bare or maybe surrounded by an insulator. Such copper wires are usually used as magnet wire in motors and transformers. They can’t be bent easily, have small applications and are relatively rigid.
Stranded copper wire: it consists of a group of copper wires which are twisted together. Stranded wire is easy to use than single strand wire, 2ndly this is more flexible. Stranding improves the lifetime of wire in applications with vibration.
Both single strand and standard conductor gives the same resistance, but their flexibility is different.
Properties of copper
Here are the properties, which make copper, ideal for electrical wiring.
Is Copper a Conductor of Electricity?
It is the measure of the material’s ability to transport the electric charge. This property is very important in electric wiring systems. From all non-precious metals, copper has the maximum electric conductivity with the electric resistance of 16 nΩm. The wires made of this reddish color metal have ability to carry more current per diameter of the wire.
Is copper a conductor of electricity? The reason behind has high electric conductivity of copper is that, in a single copper atom, the outermost 4s energy level is half filled, as there is only one electron in last shell of copper. So overall, all atoms have available electrons for the passage of current. Now, when external electric field is applied, the conduction of electrons accelerates them towards the electropositive end, thus causing an electric current. These electrons also feel resistance, when they collide with impurity atoms or lattice ions.
Although copper is more dense than some electrically conductive metals but even then it requires less cross section to carry the same amount of current.
It is defined as the measurement of the force which is needed to pull an object (wire or rope) to a point, where it breaks. The reason behind the extensive use of copper is also that copper has high tensile strength of 250 N/mm2. This large value helps to resist stretching, creep, nicks and breaks.
It is the ability of material by which it can be drawn into wires, or the ability to deform under tensile strength. Copper can be stretched to much length without breaking, hence it can also be drawn into wires. After gold and silver, copper has maximum ductility, which makes it very important in metal working.
Ductility and strength, combined
Usually it is seen that if a material is stronger then it is less flexible, but it is not true for copper. High ductility and high strength of copper makes it ideal in wiring systems. Without stretching and breaking, copper can be twisted, bent or pulled at terminations.
Under “load, no load conditions”, due to continuous expansions and contractions, the gradual deformation of material is known as creep. It can affect electrical system adversely like terminations can lose which can further cause dangerous arcing. To overcome this difficulty, copper can be used as it minimizes the loosening of connections. However if some other material is used then it must be checked periodically to ensure that screws are tightened.
Corrosion means, weakening of material due to the chemical reactions. Copper has ability to resist corrosion caused by humidity, moisture and pollution. The chemical properties of copper metal make it long-lasting and able, enough to resist abrasion and other factors which can shorten the life of copper wire.
Co-efficient of thermal expansion
Usually, solids contract on cooling and expand on heating, but this factor causes problem in electric systems. However, copper can be used to handle this problem as it has low co-efficient of thermal expansion. On the other side, aluminum, which is the alternate common conductor, expands nearly one 3rd more than copper.
The ability of material to conduct heat is known as thermal conductivity. Usually in electric systems, high thermal conductivity is required, as much part of heat is dissipated at connections and terminations. Copper is used, in this regard, as its thermal conductivity is 60 times better than that of aluminum.
In this planet earth, copper is found in abundant quantity, which is also a factor for its enough use. It has been estimated that in the upper 1 Km of earth, quantity of copper is 1014 tons, which is sufficient to fulfil our needs for next 5 million years. Here, it can be seen that how copper looks like, when taken out.
It is a process in which 2 or more metals are joined by heating process. It is usually required in electrical systems. Copper is soldered for making durable connections.
Easy to use
Copper wiring don’t need any special tools, washers, joint compounds or pigtails, because of its properties like hardness, flexibility and strength. Its flexible behavior helps in joining, while its hardness helps in keeping connections secure. It is easily bent and twisted without being broken. It can be connected without special lugs and fittings. The combination of all of these factors makes it easy to use.
Standing by high temperature
Usually in electric lines, there is fluctuation of current i.e. sometimes value of current falls and sometimes increases. So the wire must have enough capacity to withstand with such fluctuations, and yes, copper wires can.
Copper is relatively inexpensive as compared to other metals. For example, gold is an excellent conductor of electricity, but it is too much expensive than copper. So, definitely, it can’t be used for wiring system, as it will be completely the wastage of money, so copper is superior in this regard too.