Draw a schematic diagram of household/domestic wiring. Give its essential features.
Domestic wiring: A schematic diagram for household electric installation is shown in Fig. The main features are:
(i) The electric supply from the mains is delivered to our homes using a three core cable. One wire with red insulation cover is called live wire which brings in the current. The second wire with black insulation is called neutral wire which provides the return path for the current. The third wire is the earth wire. The potential difference between line and neutral wires is 220 volts in India.
(ii) The earth wire is either thick uncovered copper wire or a copper wire with green insulation. It is usually connected to a metal plate deep in the earth near the house. It is used as a safety measure which does not affect the supply in any way.
(iii) The wires from the supply line pass into the watt-hour-meter through a main fuse. Then through a main switch, these wires enter a distribution box.
(iv) From the distribution box, several independent distribution circuits are drawn which go into different parts of the house. The live wire of each circuit passes through a separate fuse so that during short circuiting, only the electricity to that part of the house is cut off and others are not affected.
![Domestic wiring: A schematic diagram for household electric installat](/application/zrc/images/qvar/SCEN10054253.png)
(v) In any part of the house, all appliances are connected in parallel to each other across the live and neutral wires. This ensures full voltage across each appliance from the mains. Each appliance is provided with a separate switch in its live wire for its operation.
(vi) Two separate circuits are used, one of 15 A for appliances with higher power ratings and the other of 5 A rating for bulbs, etc.
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