Electrical Safety



  • Fuses are purposely weak parts of circuits. 
  • They "blow" when an electrical surge happens.
  • This saves the device and means you replace the fuse
  • In the fuse, there is a thin wire
  • The current passes through the fuse and the wire gets hotter.
  • If the current exceeds a certain value the wire melts.
  • This breaks the circuit and stops the current

A disadvantage of fuses is they need to be replaced each time they blow.

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Circuit breakers

Circuit breakers

  • Can be alternatives to fuses.
  • They detect a change in the current and safely switch off the supply.

An advantage of circuit breakers is that once a fault is fixed they can be switched back on again, whereas a fuse has to be replaced.

Another advantage of some types is that they work very quickly, so can save lives. A fuse takes time to melt and will not prevent you getting a shock if, for example, you touch a live wire.

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