Lightning Arrester Types & Key Applications

2025-05-10 13:24:35

Lightning Arresters protect electrical systems from surges caused by lightning or switching events. This guide explores common types, their applications, and critical selection criteria for optimal performance.  

Core Types & Features  

1. Rod Gap Arrester  

   - Structure: Two metal rods separated by an air gap.  

   - Application: Low-cost protection for 6-10kV lines, substation entry points, and rural grids.  

   - Limitation: Requires manual reset after discharge.  

2. Horn Gap Arrester  

   - Design: Adjustable horn-shaped electrodes for controlled arc extinction.  

   - Use: Historical systems, replaced by modern types due to maintenance needs.  

3. Multi-Gap Arrester  

   - Mechanism: Multiple series gaps for staged voltage breakdown.  

   - Application: Medium-voltage industrial equipment (e.g., transformers).  

4. Metal-Oxide Arrester (MOA)  

   - Tech Edge: ZnO blocks with nonlinear resistance; no gap, rapid response (<25ns).  

   - Use: High-voltage grids (500kV+), solar farms, data centers.  

5. Electrolyte Arrester  

   - Function: Liquid/gel electrolyte for ionized discharge (rare in modern systems).  

 Ideal Arrester Characteristics    

- Zero leakage current under normal voltage.  

- Instant breakdown at abnormal voltages (e.g., >1.2x rated).  

- High current capacity (e.g., 50kA surge handling).  

- Self-recovery after transient voltage subsides.  

 Application Scenarios  

1. Power Grids  

   - MOA for substations and UHV lines.  

   - Rod gap for rural 10kV feeders.  

2. Renewable Energy  

   - MOA with polymer housing for salt-resistant PV/wind farms.  

3. Communication Systems  

   - Multi-gap arresters for RF/SCADA Surge protection (e.g., PTI-BB50 series).  

 Selection Factors  

- Voltage Level: MOA for >35kV, rod gaps for <10kV.  

- Environment: Polymer-housed MOA for coastal zones; porcelain for dry climates.  

- Cost: Rod gaps (low) vs. MOA (high reliability).