Key Points for Maintenance of Lightning Arresters: Essential Tips for Optimal Performance

2025-03-06 13:04:52

Lightning Arresters are vital for protecting electrical systems from damaging surges caused by lightning strikes and voltage spikes. Regular maintenance ensures their reliability and extends their lifespan.

 1. Regular Visual Inspections  

Conduct quarterly visual checks to identify:  

- Cracks or damage to the housing (especially polymer-housed arresters).  

- Corrosion on Terminals or grounding connections.  

- Pollution buildup (dust, salt, or industrial contaminants).  

Tip: Clean surfaces with a dry cloth or isopropyl alcohol to prevent tracking.  

 2. Leakage Current Testing for ZnO Arresters  

Modern Zinc oxide arresters require monitoring of resistive leakage current to detect aging or contamination. Use a portable leakage current analyzer to measure:  

- Normal range: Below 1mA.  

- Action threshold: Values exceeding 2mA indicate potential failure.  

Note: High leakage current increases heat generation, risking thermal runaway.  

3. Thermal Imaging for Hotspot Detection  

Perform infrared thermography during peak loads to spot abnormal heating. Common issues include:  

- Loose connections at Terminals.  

- Degraded ZnO blocks causing internal resistance issues.  

Standard: Temperatures should not exceed 10°C above ambient.  

4. Insulation Resistance Testing  

Use a megohmmeter (Megger) to verify insulation integrity:  

- Test voltage: 1kV for low-voltage arresters; 5kV for high-voltage systems.  

- Minimum resistance: 1000MΩ for 110kV systems (per IEC 60099-4).  

5. Monitor Surge Counters  

Track discharge events via built-in surge counters. Replace the arrester if:  

- The count exceeds the manufacturer’s rated limit (e.g., 20 surges for a 33kV arrester).  

- Frequent surges suggest an undersized arrester for the location.  

 6. Preventative Measures  

- Upgrade older arresters: Replace silicon carbide (SiC) models with maintenance-free ZnO arresters.  

- Environmental protection: Install shields in high-pollution or coastal areas.  

- Annual professional testing: Hire certified technicians for advanced diagnostics.  

 Why Proper Maintenance Matters  

Neglecting arrester maintenance can lead to:  

- Equipment damage from unmitigated surges.  

- Safety hazards like fires or arc flashes.  

- Regulatory non-compliance fines.  

By following these steps, you’ll ensure your lightning arresters provide reliable, long-lasting protection—critical for power grids, industrial facilities, and renewable energy systems.