Also known as a surge protection device, a surge arrester protects electrical appliances and equipment from over-voltage caused due to external factors like lightning and internal factors like switching instances. They are protective devices that limit voltage by discharging or bypassing surge current.

Whenever the voltage received by an electrical appliance is higher than the fixed voltage, they are susceptible to damage or even blow up. A surge arrester plays a crucial role during such times. Surge arresters ensure that this high amount of voltage does not reach the appliance by redirecting it into the earth wire. Hence, it stops the high voltage from reaching the appliances.