Lightning Arresters, or surge arresters, are a device that is installed to protect homes, structures, and power lines from dangerous surges of power.
Lightning Arresters are typically installed near critical appliances or points of entry, such as an electrical panel. When potentially unpredictable lightning strikes, the arrester activates and diverts the lightning to the ground, where it will disperse safely.
Role of Lightning Arrester
- Events of Lightning: Major lightning incidents in recent times caused damage to infrastructures and posed a threat to human life. This interrupted the performance of power systems, where the high transient voltages caused flashovers across the terminals of electrical equipment. The causes of equipment breakdown were also elaborated on using case studies.
- Structure of Lightning: Protection radius and attachment distances of various types of lightning involving current magnitude and polarity were explained. The choice of protection mechanism to be implemented for application-specific needs was discussed.
- Selection and Installation of Lightning Arrester: Technical concepts, for the selection of the appropriate surge arrester, were discussed. Clearances and distances necessary between adjacent equipment and lightning arrester for protection of the equipment were deliberated. Discussions put light on myths and misconceptions regarding the selection and installation of lightning arresters. The positioning of lightning arresters in close vicinity to the equipment under protection and reflections leading to voltage doubling was clarified.
- Design and Maintenance: The design and maintenance aspects of the Lightning arrester were explained with some unique real-time projects carried out by MEPL across the world such as Burj Khalifa, Ain Dubai, and Creek Tower using the EMTP-RV simulation platform. Basic maintenance procedures and their importance were also discussed among the experts.
- THRC: Performance and health of the surge arresters depend on the property of the metal oxide(ZnO) and integrity of hygroscopic sealing. However, deterioration due to aging or anomaly increases 3rd harmonic leakage current, the magnitude of the resistive current, and the degree of non-linearity of voltage/current characteristics of metal oxide. Limits of THRC values and other major nuances in the testing of Lightning arrester were also discussed
