why we use aluminium as a transmission line
why we use aluminium as a transmission line
As we know that the best conductor in electrical engineering is "Silver". Because, the moveablity of electron of silver is very high as compared to other conductor or metal. Due to high cost of silver so we cannot use silver as a transmission line or house wiring.
Reason for using aluminium as a transmission line:-
There are following reason that why we use aluminium as a transmission line are:-
1. Cost:- The cost of the aluminum is less then Sliver and Copper. And, also the conductivity of the aluminum is less then silver and copper so, we take thick wire of aluminum as a transmission line.
2. Resistivity:- The resistivity of the aluminum is higher then copper, so we use thick aluminum wire as a transmission line.
3. Corrosion:- The oxidation of copper is so easily and fastly as compared to aluminum metal. In other words, the rusting or corrosion of copper is so easily as compared and quickly to aluminum. Hence, copper required more maintenance as compared to aluminium metal.
4. Lifetime:- The life or strength of aluminium metal is very higher than copper, because copper rust easily in atmosphere or presence of water.
5. Weight:- The weight of aluminium metal is less than copper metal.
6. Heating effect:- The heating effect of aluminium is less than the copper so we use aluminium as a transmission line or distribution line.
Why can't use insulation in transmission line?
Firstly, let us understand that the reason of using insulation on wire:-
1. Lekage electrical current:- Insulation help us to protect from lekage current. The wire required a ground to connect here insulation help to protect from lekage current or destruction current.
2. Sepeeating electric conductor:- It is used to separate two or more from each other. Let take a example to understand this property, consider two wire red and yellow phase wire, if there are attract to each other then there short circuit occure. So, Insulation help us to separate wire to each other.
3. Protect again environmental threats:- The copper wire is easily reusted or oxidized in environment. So, here we use insulation for protact our electric wire from environment threats.
4. Electric shock:- If human being, touch live wire then it get shock from this. Here, insulation help us to protect electric shock.
5. Mechanical strength:- Insulation gives us a Mechanical strength of our electric wire.
Now, comes to our topic that reason of can't use Insulation on transmission line or overhead transmission line:-
1. The overhead transmission line is on air or a some height so there is no lekage of electric current. So, we can't use insulation of overhead line.
2. The three phase wire are separately to each other.
3. The rusting or oxidation of aluminium is not easily as compared to copper. So, insulation required on copper not on aluminium.
4. If we insulted Aluminum wire then it will be much expancice.
5. Due to heating effect we can't use Insulation on overhead transmission line.