Topic 2 - Electrical Safety Flashcards
what are the wires in a plug called?
live, neural, earth
what is the voltage of a live wire?
it alternates between a high positive and negative voltage of about 230V
what is the voltage of a neutral wire?
0V
which wires does electricity flow through?
the live wire and the neutral wire
what doe ‘earthing’ a metal case mean?
attaching a case to an earth wire so it cannot become live
why do appliances with a plastic casing not need to be earthed/an earth wire?
plastic is an insulator
what happens if a fault develops in an earthed case?
a large current flows through the live wire, the case and the earth wire, blowing the fuse so cutting off the live supply.
why is a circuit breaker more convienient compared to a fuse?
it can be easily reset
why is a circuit breaker safer than a fuse?
they break the circuit immediately, no time is wasted waiting for a fuse to melt. they also work for small current changes that wouldn’t melt a fuse.
