Conclusion

Requirements for the components of grounding systems in the standards we've analyzed above should be harmonized. There should not be any situations where different standards define different requirements. The current situation indicates a lack of cooperation between different groups working on the standards. Standard PN-HD 60364-5-54 has been developed by IEC / TC 64 workgroup, which specializes in low voltage electrical systems and electrical safety. Standard PN-EN 50522 has been developed by IEC / TC 99, which specializes in electrical systems with voltages greater than 1 kV AC and 1,5 kV DC, and a series of standards PN-EN 62305 and PN-EN 62561 were developed by IEC / TC 81 group, which specializes in lightning protection.

Commercially available products mostly have sizes that meet the requirements of one certain standard. However, some differences, such as the thickness of copper bonding for steel rods (90 microns according to PN-EN 50522; 250 microns according to other standards) can be of great importance during long-term operation. Tables 3 to 5 contain proposals for the harmonization of the recommendations related to the size and thickness of coatings, developed on the basis of the standards under discussion for elements that are used most often: wires, tapes and rods.

Table 3. Wire materials and minimum dimensions

Table 4. Tape materials and minimum dimensions

Table 5. Rod materials and minimum dimensions

When analyzing the latest lightning protection standards, as well as standards related to electrical systems, one can say that grounding made of copper-bonded steel is currently the most optimal solution. At current prices for components made of pure copper and stainless steel, as well as at high risk of theft, this solution is the most cost-effective. Only components with a corresponding copper bonding thickness (250 microns for rods and 70 microns for tapes) meet the requirements of all lightning protection and electrical systems standards and are approved for the use in any case, along with artificial ground electrode systems connected to the foundation grounding.

Recommendations contained in the lightning protection standards mean that additional artificial ground electrode systems based on zinc-coated wires are not compatible with foundation electrodes. Therefore, this kind of solution requires the designer to make a clear substantiation that takes into consideration both the expected corrosion threats and the need for additional expensive protective equipment (spark gaps and protective barriers).