Currently, railroad transport experiences significant changes. High-speed trains rich in electronics have appeared, and various automation means have been implemented. All of this requires relevant regulatory framework, therefore, GOST R 58232-2018 Railroad Infrastructure Facilities has been introduced. Complex Protection Against Lightning and Transient Surges. General Requirements".
Note the title page of the official revision of this standard. It states "Implemented for the first time". It means that lightning protection issues at the railroad were, for the first time, raised to the national standard level. Previously, they were regulated by both department instructions and general documents. In the second case, the documents include RD 34.21.122-87 and SO 153-34.21.122-2003.
How does GOST R 58232-2018 principally differ from the previous documents?
GOST R 58232-2018 is based on the integral approach to the lightning protection systems design. When choosing lightning protection means, the entire facility as a whole is considered, without dividing it to the elements of railroad infrastructure subsystems. The impacts of atmospheric and switching interference should be considered together. eparate consideration of these factors is not allowed. The lightning protection system should also provide, when required, electrical safety and electromagnetic compatibility between separate elements of railroad infrastructure.
Another feature includes risk-oriented approach as per GOST R IEC 62305-2-2010 "Risk Management. Protection Against Lightnings. Part 2. Risk Evaluation." Loss risk reduction to a particular level is the main task. In addition to risk indicators, social importance of lightning effect loss is also considered. This approach is essentially new for the Russian practice compared to the previous calculation methods.
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Moreover, there exists the international standard for lightning protection IEC 62305 consisting of three parts. At the time of adoption of GOST R 58232-2018, the first and second parts of IEC 62305 standard were translated and adapted, and based on this, the respective GOST standards were issued. And the third part was only adapted in 2021 as GOST R 59789-2021 "Lightning Protection. Part 3. Protection of Buildings and Structures from Damage and Protection of People and Animals from Electrical Injuries" has been introduced. This standard came into effect on March 1, 2022.
However, these difference do not affect GOST R 58232-2018. The point is that the methods for the lightning arrester parameter calculation provided in the mandatory Appendix A to the standard repeat the methods provided in SO 153-34.21.122-2003. Often (but not always), in the remaining part, GOST R 58232-2018 also provides the same or even stricter requirements to the lightning protection system design compared to GOST R 59789-2021. For example, GOST R 58232-2018 does not permit the presence of loops at current collectors while GOST R 59789-2021 permits them with certain limitations. Note that GOST R 58232-2018 considers facilities typical exactly for the rail road. If you need to design the facilities which are rare for rail road, you should consult the common regulatory documents for the lightning protection.
GOST R 58232-2018 also contains a reference to the provisions of "EIC, Rev. 6, of 1979, as revised on June 20, 2003". Probably this is a mistake and it should be the EIC, Rev. 7, since even on January 1, 2003, Rev. 6 was officially invalidated. By the way, as of 2022, the EIC is officially classified as the reference document. The reason is that the respective GOST should have been issued to replace these Regulations, but it hasn't yet been done. However, due to the absence of other regulatory documents, the EIC is still used both for design and evaluation of proper fulfillment of work by the customers.
Examples of discrepancies between GOST R 58232-2018 and other regulatory documents
As noted before, GOST R 58232-2018, although it is based on risk-oriented approaches in lightning protection not previously used in Russia, however, according to the calculation methods, it mainly follows SO 153-34.21.122-2003. Generally, this GOST replaces the said document in full. But during the development of the lightning protection system, instructions RD 34.21.122-87 based on many years of scientific studies of Russian researchers and great practical experience are still used as a reference. GOST R 58232-2018 may contradict it.
At the rail road, spaces wider than 100 m such as stations and depots are typical. According to item 1.9 of RD 34.21.122-87, such large buildings should provide a continuous electrical coupling between carrying structures if they function as natural grounding arrangements. If bearing structures cannot be used as such grounding electrodes, it is required to be installed "inside the building in the ground at the depth of at least 0.5 m, lengthy horizontal electrodes having a cross-section of at least 100 mm. The electrodes should be installed at least every 60 m along the building width and attach it from both side at the edges to the external grounding circuit". GOST R 58232-2018 requires the use of grid radial equipotential bonding system in the buildings being a part of the railroad infrastructure as per GOST R 50571.4.44-2019. In this case, the system parameters are not related to building dimensions, but if the facility is located on a high-speed railroad, it is required to also create a continuous closed bus along the perimeter for each separate space. If any cables in addition to fiber optics are laid between the rooms, their equipotential bonding systems should be interconnected.
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Critical railroad facilities can mostly be conceived as data centers, i.e. it is lightning protection Category II according to RD 34.21.122-87. In case of a non-metal roof, it is recommended to use the grid lightning arrester. According to item 6.2 of GOST R 58232-2018, the grid size should not exceed 5 x 5 m, while at the same time item 2.11 of RD 34.21.122-87 prescribes 6 x 6 m. It has some logical reason, i.e. GOST is more modern and refers to hazardous facilities. But then, GOST defines less strict requirements: according to item 6.23, the grid should also be installed through roof projections. At the same time, item 2.11 of RD 34.21.122-87 requires to install additional lightning arresters connected to the grid on non-metal projections of the roof, and to connect metal projections with the grid.
Item 2.11 of RD 34.21.122-87 prescribes to use the roof (if it is metal) as a lightning grid. No special requirements for the roof are established. The point is that, in 1987, when these instructions were adopted, there was no such choice of metal roofs (e.g. metal tiles were not common), therefore, almost any metal roof brand existing at that time could be used as a lightning rod. With regards to GOST R 58232-2018, item 6.3.1 states clear criteria determining which metal roofs are suitable and which are not.
Item 1.8 of RD 34.21.122-87 states that usually natural ground terminals must be used, i.e. building foundation (a similar statement is also present in item 3.2.3.3 of SO 153-34.21.122-2003). GOST R 58232-2018 does not recommend natural grounding terminals as basic ones, while they are still allowed if conditions provided in item 6.4.2 are met. Generally, the requirements listed therein may be fully met only for the building where, initially, the respective foundation design was provided for during the construction, i.e. designed after the publication of this GOST. There are also discrepancies with the provisions of GOST R 59789-2021 (although this standard is also based on risk management principles) where the specifics of the natural lightning arrester design are not rated but the requirement to the low-frequency grounding resistance exists.
Conclusions
To design the anti-surge system at the rail road, in addition to GOST R 58232-2018, there is also at least one GOST and two instructions. If the requirements therein are stricter, it is reasonable to use them. At the same time, common regulatory documents can establish other requirements, and it is not always possible to compare their strictness, since they are based on different approaches. Contact the ZANDZ Technical Center for lightning protection and grounding calculation.
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