Can Copper PVC Cable Be Used to Connect to Air Terminals in Lightning Protection Systems?
In lightning protection systems, the selection of conductive materials and types for connecting air terminals (lightning rods) is very important. Using copper PVC cable to connect to air terminals is not the best choice, and the main reasons are as follows:
1. Conductivity
Copper Wire: Copper is an excellent conductor and can effectively carry lightning current.
PVC Insulation Layer: The PVC insulation layer may melt or burn due to high temperatures during a lightning strike, affecting conductivity and safety.
2. Weather Resistance and Corrosion Resistance
Copper Wire: Copper has good weather resistance and corrosion resistance, making it suitable for long-term outdoor exposure.
PVC Insulation Layer: The PVC insulation layer can degrade over time when exposed to UV radiation, humidity, and temperature changes, reducing its insulating properties and mechanical strength.
3. Standards and Regulations
International and National Standards: Many international and national standards (such as IEC 62561, NFPA 780, GB 50057, etc.) have clear specifications for the materials and types of conductors used in lightning protection systems. These standards typically recommend the use of bare copper wire or tinned copper wire, rather than insulated cables.
Safety and Reliability: The materials and types specified by standards are designed to ensure the safety and reliability of lightning protection systems. Using non-compliant materials can pose safety hazards.
4. Installation and Maintenance
Bare Copper Wire: Bare copper wire is easy to install and inspect, allowing for a clear visual check of the wire's condition.
Copper PVC Cable: During installation and maintenance, the insulation layer of copper PVC cable can be damaged, affecting conductivity and safety.
Recommended Practices
Bare Copper Wire: It is recommended to use bare copper wire to connect air terminals. The wire cross-sectional area should be selected based on the magnitude of the lightning current and standard requirements.
Tinned Copper Wire: Tinned copper wire can also be used to improve corrosion resistance.
Grounding System: Ensure that the connection between the wire and the grounding system is reliable, and the grounding resistance should meet standard requirements.
Conclusion
Although copper PVC cable has good conductivity, its insulation layer can be damaged during a lightning strike, and it has weather resistance issues when exposed to outdoor conditions for a long time. Therefore, it is not recommended to use copper PVC cable to connect to air terminals in lightning protection systems. It is recommended to use bare copper wire or tinned copper wire to ensure the safety and reliability of the lightning protection system.
