Connected to the live wire, a surge causes a huge amount of current to flow through the fuse, heating up the thin wire inside which then melts and breaks the circuit
How circuit breakers work
Break the circuit whenever there's a surge, but they don't get permanently damaged, they just get tripped and turn off the circuit, making them easily resettable
Circuit breakers are a bit more expensive than fuses
Fuses come in different ratings depending on the current they need to break the circuit for
If the live wire comes loose inside an appliance
It can touch the casing and cause a big electric shock
Safety precautions to reduce risks with electricity
Fuses
Circuit breakers
Earth wires
Double insulation
The benefit of fuses is that they are simple and cheap, but the downside is that they are permanently broken after a single surge and need to be replaced
Double insulation of an appliance
The entire appliance is covered in a plastic casing so that there are no exposed metal parts that can be touched, preventing electric shocks
Earthing
Provides an alternative pathway for the current to flow away, diverting any electricity through the earth wire rather than through us
Whenever you deal with electricity, there's always a risk that something will go wrong
If an appliance has double insulation, it won't need an earth wire
One of the most common problems with electricity are sudden increases in current, known as surges
Surges can happen
When something changes in a circuit like when you turn an appliance on or off or because of a fault in the circuit or appliance
