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o When they come into our houses, they pass through a circuit called a Fuse.
Whenever there is a high voltage, voltage fluctuation, overloading, short circuit the
fuse melts and prevents the high voltage reaching the electric appliance. This saves
the electrical gadget.
o Then through the metre board in the house, these wires pass on to different electric
gadgets
o Generally 2 types of electric circuits are used at homes
o 15A : Appliances which have higher power ratings. (geysers, refrigerators, ACs)
o 5A: Appliances which have lower power ratings. (TV, bulbs, fans)
o Inside the house, the live and neutral wires are connected to the input terminals
of kWh meter, while the earth wire is connected to the body of the kWh meter.
The kWh meter-reads the units of electric energy (in kWh), consumed in a house.
Without the kWh meter, it is not possible to correctly note the electric energy
consumed in a house or by an electric appliance.

o The live wire coming out from the output terminal of kWh meter has another fuse
in it which is called the main fuse. If the main fuse blows off the entire circuit of
the house wiring system is disconnected from the mains supply.
Beyond main fuse the live and neutral wires are connected to a main switch
which consists of a double pole iron clad switch. This switch can cut off the live
and neutral wires from house hold circuit by operating a single lever. The iron
casing of the main switch is locally earthed. Then the power flowing out of the
main switch is distributed in house by the common ring or three wire systems.
The diagram illustrates the working of the kWh meter, the main fuse and the
main switch.