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PROTECTION DEVICES
Look at these devices. Give their names. What do they all have in
common?
CIRCUIT BREAKERS FUSES SWITCHES RELAYS
Fig.17
Vocabulary preview
Study the following words and try to use them in this topic
fuse – n,[C] a small safety part in an electrical device that causes it to stop
working if the electric current is too high, and so prevents fires or other
dangers:
If the demand for electrical current exceeds the safety level, a fuse
opens once and must be replaced to reconnect the circuit.
circuit breaker - n, [C] a safety device that stops the flow of current in an
electrical circuit when there is a fault:
There was a loss of power after a strong
gust of wind tripped a circuit breaker.
relay – n, [C] an electrical device, typically incorporating an
electromagnet, which is activated by a current or signal in one circuit to open or
