Studied by 0 people
Amount of energy used in home
kWh = units
Ac
Alternating current
Dc
Direct current
Where is ac used ?
Mains power
where is Dc used ?
Battery’s
W - Kw
X 100
Seconds - hours
X 3600
Min - hours
X 60
Live wire
Carries high voltage into device
Earth wire
Carries extra current into earth if needed
Neutral
Completes circuit and is low voltage
Colour of live wire
Brown
Colour of earth wire
Green/ yellow stripe
Colour of neutral wire
Blue
Benefits of ring main
Any socket will have 230v
Each socket is independent
If one part breaks the others will still work
What type of circuit is a ring main ?
Looped parallel circuit
Advantages of mcb
Resettable
They act faster
Rccb
Residual current circuit breaker
what does a fuse do?
If there’s too much current the fuse will blow (melt) and break the circuit
What does a Mcb do ?
If too much current flow the circuit gets broken by an electromagnet
What does a Rccb do ?
If there’s a difference between the current in the live and neutral wire the Rccb switches off the circuit
Wires have plastic coating
Good insulator
Can be identified (colour)
Benefits of using less energy
Save money
More environmentally friendly
Note 
Flashcard (34)