What function does a surge arrester perform in switchgear?

A surge arrester is a crucial component in switchgear that serves primarily to protect the equipment from voltage spikes, which can occur due to various reasons like lightning strikes or switching operations within the electrical system. When these transient overvoltages occur, the surge arrester diverts excess voltage away from sensitive components, thereby preventing damage that could lead to costly repairs or system failures.

In this context, the function of the surge arrester ensures that the voltage level remains within safe limits, effectively safeguarding the infrastructure and prolonging the lifespan of the switchgear. This protection mechanism is essential for maintaining the reliability and stability of the electrical system.

Other options relate to functions that are not the primary purpose of a surge arrester. Regulating power supply and enhancing circuit breaker performance involve different technologies and approaches, while improving energy efficiency typically pertains to optimizing power use and losses, which is outside the scope of what a surge arrester does.