Whats the difference between aluminum wires and copper wires?

Copper wires are made of copper and aluminimum wires are made of aluminimum.
Don't work aluminimum wiring unless you know exactly what you are doing. It will react with copper wire and wiring devices and will start a fire. There is special grease and wiring devices to prevent this that you need to use. If you have aluminimum wire, make sure you do your homework.


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The electrical capacity of any type of cables/wires are depending on the heat withstand capacity of the material wich can be calculated with the product of square of current, Resistance of the material and Total time for flow of current. I2RT. Resistance again can be calculated as R=rho*L/A where rho is the resistivity, L is the length and A is the area of cross section. So for a fixed current flow and fixed Length of wire the area of cross section of the cable is directly propotional to the resistivity. resistivity of copper is 1.68x10 power -8 and that of Pure Aluminum is 2.82x10 power -8. So.. for a specific current flow, an aluminum cable size shall be 1.7 times that of copper cable. This also is not recommented as the Aluminum resistivity varries with the alloys and even with casting. 2.5 times the size of copper can be recommented for Aluminum cables. Also as the temporature expansion of Aluminum is 3 times that of copper. So all the termination and joining areas shall be treated more sensible that of copper.
No need to be afraid to use Aluminum cable if you work with the proper recommented size.