Domestic Electricity Supply

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Domestic Electricity Supply
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3 wires in the cable
3-pin plug
cable
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Brown insulation for live wire
Blue insulation for neutral wire
Copper wires
Green/yellow insulation for earth wire
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(No Transcript)
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Inside a 3-pin plug
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A fuse connecting the live wire to a pin on the
plug
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The plug with the fuse removed
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A fuse with fuse value of 13 A
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Pin connected to the earth wire
Pin connected to the live wire
Pin connected to the neutral wire
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E
Plug
N
L
Socket
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A fuse a metal wire contained in a glass tube
with metal contacts at its ends.
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An earth wire connected to the metal window frame
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An earth wire connected to the metal window frame
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Consumer unit or
A typical domestic wiring
All sockets and electrical appliances are
connected in parallel. They are all operated
under the same supply voltage and independent of
each other.
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Kilowatt-hour meteris used to measure the amount
of electrical energy consumed in kWh.
(consumer unit)contains fused or circuit breaker
for different sections of wiring in the house.
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Advantage of using ring mains Current can be
delivered from the power supply to the electrical
appliance via two wires. Smaller current exists
in each wire and hence thinner wires can be used.
Thicker wire has to be used for carrying stronger
current I. Thicker wire has lower resistance r
and hence the power lost in the wire ( I2r) is
less and the temperature of the wire will not
rise to dangerous level at which the insulation
burns.
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An electric bill
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The electrical energy consumed New
kilowatt-hour meter reading Old kilowatt-hour
meter reading
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A chart showing the variation in electrical
energy consumption with seasons (maximum
temperature within two months).
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Power and Voltage Ratings of an electrical
appliance
Power rating
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Power and Voltage Ratings of an electrical
appliance
Power rating
Voltage rating
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Power and Voltage Ratings of an electrical
appliance
Power rating
Voltage rating