Lightning Arrester

Lightning Arrester(LA)/surge arrester is a protective device used to limit the effect of voltage surges on equipment or power distribution systems. The arrester helps in discharging surge current, thus protecting the system and equipment from the impact of surges and disturbances.

Fault-handling strategies for LA
Faults in lightening arrestors can occur due to physical factors or operational factors. Moisture ingress caused by faulty sealing, dust particles on the surface, cracks on the porcelain surface and partial discharges are a few examples. Ageing of parts is a gradual process, which also leads to failure. Besides a total disruption of the power circuit, LA failure can cause an explosion and splintering of porcelain, which leads to heavy damage to surrounding equipment and people. Regular and seasonal monitoring is a must to keep the Lightening Arrestor working smoothly.

Which parameters should be monitored?
Measuring the resistive current component and monitoring the 3rd harmonic component of leaked current are critical tests. Leakages between 350-500 μA require close monitoring and those beyond 500 μA call for replacement in consultation with the manufacturer. One cycle of leakage measurement should be completed before the onset of monsoons.


Motwane equipment for monitoring lightening Arrestors can be found here.

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