Electricity is delivered to homes through a main conducting cable, which may come from electric poles or underground cables.
The cable typically contains three wires:
- Live wire: Carries the current, with red or brown insulation.
- Neutral wire: Returns the current, with blue or black insulation.
- Earth wire: Provides safety, with yellow or green insulation.
In India, the voltage difference between the live and neutral wires is approximately 220V.
- The live and neutral wires are connected to the electric meter through a fuse and then to a main switch, which distributes electricity to various circuits in the home. Electrical appliances within the house are connected in parallel to the live and neutral wires, ensuring the same potential difference across all appliances.
- The earth wire is connected to a metal plate buried deep underground, serving as a safety feature to prevent electrical shocks.
- Fuse wire is used to protect appliances by breaking the circuit when excessive current flows. It is made of a material with a specific melting point. The fuse wire is connected in series with appliances.
- When excessive current flows, the wire heats up, melts, and stops the flow of current, protecting the appliances. Fuse wires are fitted in a porcelain-like non-conducting body and are available with upper current limits of 1A, 2A, 3A, 4A, 5A, and 10A for domestic use.
