Review of normative document of the republic of moldova, ncm g 02.02:2018 “organization of lightning protection of buildings and structures”

What can assist the designer in developing an external lightning protection system for a specific object? First and foremost, it is the current regulatory documents (hereinafter referred to as NTD) that govern the rules and a set of measures to complete the task. They are not only supporters but also legislators in this field. We post a lot of articles on our website, and analyze the characteristics and details of Russian normative documents. Let's broaden our perspectives!

In this article, we will look at some of the most interesting aspects of the Republic of Moldova's current regulatory documents - NCM G 02.02:2018 "Organization of lightning protection of buildings and structures", - and compare them to domestic NTD.

Does it apply to everything?

The first thing to consider is the scope of this document. It does not cover the design and installation of lightning protection for the following objects:

• railroad systems;
• motor vehicles;
• water and air transportation;
• coastal structures;
• underground high-pressure pipelines, pipelines;
• power lines and electronic communications not connected to the protected building;
• electrical parts of power stations and substations, contact networks;
• radio and television antennas, telegraph, telephone and radio broadcasting lines;
• buildings and structures, the operation of which is connected with the use, production, or storage of gunpowder and explosives.

There are variations in the scope of application when compared to the Russian Federation's normative documents, specifically RD 34.21.122-87, SO 153-34.21.122-2003, and GOST R 59789-2021. At the same time, it's crucial to keep in mind that the scope of this or that regulatory document may or may not cover standards for various directions and branches. In any case, the design should be carried out in accordance with the standards specified in the Terms of Reference (hereinafter referred to as TOR), while also taking into account the current state standards.

Interesting categorization of lightning protection levels and risk assessment

The classification of facilities in NCM G 02.02:2018 is similar to SO 153-34.21.122-2003 but more comprehensive. For example, the reliability of the lightning protection system can vary depending on the level of lightning protection and the lightning current parameters for a given level; we will refer to Table 4.5 in the document.

Table 4.5 – Probabilities corresponding to the limits of lightning current parameters.
 

Thus, the effectiveness of protection measures is assessed by the probability with which the lightning current falls within the range specified for the project, as determined by the level of lightning protection.

A separate section of NCM 02.02:2018 addresses the issue of determining whether an object requires lightning protection, determining the level of lightning protection, and establishing specific rules for performing lightning protection in individual cases. Clause 5.1.4 specifies one of the requirements:

for multi-story buildings (structures) with asymmetric architecture or formed from multiple buildings of different heights, lightning protection is performed separately for each building body and connected to each other.

The document contains methodologies for calculating risks, including their components, damages, and damage types. Based on such information, technical and economic analyses can be conducted to determine the need for a lightning protection system. For this purpose, the document includes block diagrams of the procedures for these analyses, as shown below.

Figure 6.1 - Block diagram of the procedure for analyzing the need for lightning protection of a building (structure) and selecting the necessary protection measures

Идентификация защищаемого задания (сооружения) Identification of the protected building (structure)
Идентификация типа потерь, соответствующих защищаемому зданию (сооружению) Identification of the type of loss corresponding to the protected building (structure)
Для каждого типа потерь должны быть проведены идентификация и расчет следующих компонентов риска: RA, RB, RC, RM, RU, RV, RW, RZ The following risk components must be identified and calculated for each type of loss: RA, RB, RC, RM, RU, RV, RW, RZ
Здание (сооружение) защищено The building (structure) is protected
Защита необходима Protection is needed
LPS установлена? Is LPS installed?
LPМ установлены? Are LPМ installed?
Расчет новых значений компонентов риска Calculation of new values of risk components
да yes
нет no
Установление адекватного типа LPS Establishing an adequate type of LPS
Установление адекватных LPМ Establishment of adequate LPMs
Применение других мер защиты b) Application of other protection measures (b)

Figure 6.2 - Block diagram of the procedure for assessing the cost-effectiveness of lightning protection measures

Оценка стоимости: - здания (сооружения) и доходов от видов деятельности; - внутренних линий коммуникаций и оборудования Cost estimation: - building (structure) and income from activities; - internal communication lines and equipment
Расчет всех компонентов риска Rх соответствующих R4 Calculation of all Rх risk components corresponding to R4
Расчет стоимости потерь СL в год и полных затрат СLR на остальные потери в год при применении выбранных мер защиты (см. приложение D, SM EN 62305-2) Calculation of the cost of losses СL per year and the full cost of СLR for the remaining losses per year when applying the selected protection measures (see Annex D, SM EN 62305-2).
Расчет затрат СРМ в год при применении мер защиты Calculation of СРМ costs per year when applying the protection measures
Нет No
Да Yes
Применение мер защиты от молнии экономически неэффективно Application of lightning protection measures is not cost-effective
Применение мер защиты от молнии экономически эффективно Application of lightning protection measures is economically efficient

Lightning arresters and current collectors are typically required to meet the same standards as domestic installations. However, the grounding arrangement is standardized with some variations. Domestic NTDs use a common grounding arrangement for all objects, with the exception of objects with lightning protection level I, whereas NCM G 02.02:2018 requires a separate grounding arrangement for all objects protected by freestanding lightning arresters.

The methods of calculating lightning protection provided in the Moldovan regulatory document are identical to the methods of calculating protection zones in SO 153-34.21.122-2003, with the exception that they are applicable to all objects up to 150 m high. SO 153-34.21.122-2003 recommends that the formulas be used only for the simplest lightning protection system designs: single rod, single wire, double rod, double wire, and closed wire. At the same time, if you use specialized software, both of the aforementioned documents allow you to perform lightning protection calculations for objects taller than 150 meters.

What about active lightning protection? In fact, the standard makes no mention of non-traditional devices designed to receive lightning strikes. This means that their application on the territory of Moldova will not be legally justifiable.

To summarize, NCM G 02.02:2018 "Organization of lightning protection of buildings and structures" is an independent, comprehensive, and very voluminous regulatory document that considers many requirements for various systems, as well as methods for evaluating technical and economic indicators that allow us to assess the required set of measures to protect people and objects from lightning.

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