why do we use copper or aluminium for wiring in house?
Answers
Aluminium is a good conductor of electricity, but aluminium oxide is not. Aluminium is always covered with a film of oxide. If this film is removed, the metal readily reacts with oxygen from the atmosphere, restoring the oxide film. For aluminium to be used as an electric conductor, its surface needs to be prepared at the joints. This involves coating the ends with grease, to keep exposure to atmosphere away and scraping the metal with wire brush. This will remove the oxide film and the grease will keep oxide formation away. This process should be repeated with all the conductors before joining. The joints should have a spring mechanism, to compensate for creep due to thermal stresses.
The process explained above is suitable in industrial environment, where the equipment is periodically monitored. This cannot be expected to be followed at home, where there is no maintenance schedule. Therefore aluminium conductor is not used at homes.