Earth‑Smart Lightning Arresters: High Voltage, Low Impact

Surge arresters (also known as lightning arresters) are essential over-voltage protection devices designed to safeguard electrical systems—from power lines and substations to industrial plants and residential panels—against damaging transient voltage spikes caused by lightning strikes, switching surges, or grid fluctuations. Modern arresters typically employ metal oxide varistors (MOVs) or zinc‑oxide (ZnO) elements that remain non‑conductive during normal operation but instantly clamp surges, redirecting excess energy to ground in microseconds to protect transformers, switchgear, sensitive electronics, and automation systems. Benefits include extended equipment lifespan, reduced downtime, and enhanced safety, while smart designs now incorporate real‑time diagnostics for predictive maintenance. Choosing the right arrester—considering voltage class, energy‑handling capacity, and industry compliance—ensures reliable, cost-effective protection across power transmission, renewable energy, telecommunications, and commercial/residential installations 

 

Purpose & Function

• A surge arrester is designed to safeguard electrical equipment from sudden overvoltage spikes triggered by events like lightning strikes or switching transients. It does this by clamping voltage surges and routing the excess energy safely to the ground

• It remains highly resistive under normal conditions but becomes a low-impedance path during a surge—conducting current to earth and protecting connected devices.

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Applications Across Systems

1. Power Transmission & Distribution

• Installed on transmission towers and distribution lines to prevent lightning-induced flashovers.

• Used in substations to protect transformers, switchgear, busbars, and control systems from both lightning and switching surges.

2. Industrial Facilities

• Shields motors, generators, PLCs, automation systems, and sensitive electronics in industrial plants from voltage transients.

• Common in environments like mining, manufacturing, and process control to enhance reliability.

3. Residential & Commercial Buildings

• Placed at main service entrances or distribution boards to protect household wiring, appliances, computers, telecom, HVAC, and medical equipment.

4. Specialized Applications

• Used in renewable energy systems (solar inverters, wind turbines), communication systems, railway signaling, HDVC systems, capacitor banks, and polluted/seismic regions.

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Types & Classes

• Metal Oxide Varistors (MOVs): Fast-acting, widely used in low-to-medium voltage setups.

• Gas Discharge Tubes (GDTs): Handle very high-energy surges often paired with MOVs.

• Silicon Carbide & Zinc Oxide Arresters: Traditional and modern varieties, with ZnO being standard in high-performance units.

• Class Ratings:

  • Station class for substations

  • Intermediate for industrial/commercial

  • Distribution class for poles and panels

  • Secondary for low-voltage, residential electronics