circuit breaker

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Switching device designed to protect an electric circuit from overloads such as excessive current flows and voltage failures. It has the same action as a fuse, and many houses now have a circuit breaker between the incoming mains supply and the domestic circuits. Circuit breakers usually work by means of magnetic-type relays or solenoids. Those at electricity-generating stations have to be specially designed to prevent dangerous arcing (the release of luminous discharge) when the high-voltage supply is switched off. They may use an air blast or oil immersion to quench the arc.

When a current exceeds a fixed limit as it flows through the magnetic coil of a circuit breaker, a triggering mechanism is released, pulling the contacts apart and opening the circuit, thus preventing any more current flowing. Circuit breakers have many advantages; for example, they are fast acting, can be adjusted to operate at different current values, and can be easily reset.

Black reflects the African origins of the islanders. Red stands for the vigour of the people. White represents hope. Effective date: 27 February 1967. >>