Webinar «International electrotechnical standard IEC 62305. General principles», page 1

The first webinar of a series "Grounding and lightning protection: IEC 62305 standard"

A lightning strike into a building (structure) or near it is a source of danger to life and health of people, the integrity of the building (structure), its internal objects and utilities. Therefore, the development and implementation of protective measures against lightning is a very important task.

Recommendations provided in this standard allow developing effective protection measures to ensure the reduction of the risk of shock resulting from the lightning strike.
The "General Principles" section studies the following issues:

1. The damage that may be caused by the lightning strike depends on a facility and the exact impact point.
The lightning strike into a building (structure) can cause damage directly to the building (structure), injuries and loss of life, as well as damage to property, including failures of internal systems in the building. Damage and failures may occur in the territory in the vicinity of a building (structure) and cover the surrounding area. The scale of destruction escalation depends on the specifications of the building (structure) and lightning strike parameters.
This section describes:
a) the impact of lightning on a building (structure);
b) sources and types of damage to buildings (structures);
c) the types of losses.

2. Economic feasibility and requirements for lightning protection. 
To reduce the social losses, the need for the protection of the building (structure) from lightning strikes should be assessed. To assess whether lightning protection is really necessary, the risk assessment is carried out in accordance with the procedures set forth in IEC 62305-2.

3. Safety measures and their choice:
a) measures to protect people against death and serious injuries from electric shock;
b) protective measures to reduce physical damage to the building (structure);
c) protection measures to reduce failures of electrical and electronic systems.

4. Main criteria for the protection of structures.
A perfect protection of a building (structure) supposes that the facility to be protected is grounded, fully shielded with a conductive shield of an appropriate thickness and has an adequate connection at the entry point of communication line shield of the building (structure). Such protection can prevent penetration of the lightning current and its electromagnetic fields into the protected facility and prevent dangerous thermal and electrodynamic effects of current, and consequently the risk of fire and voltage surge in internal systems. However, in practice, it is often impossible and economically unfeasible to ensure the ideal protection.

Dr. Marek Loboda has been a member of the committee for the development of this standard and knows about all the problems faced by lightning protection designers and other professionals working with the regulation at first hand. Join our online meetings to understand the essence of the document and solve all problems related to the implementation of lightning protection systems!

Webinar text. Page 1

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Estimated reading time: 44 minutes

— Before starting to talk about standards and requirements, I will tell a few words about myself. As Anastasia has just said, I am the assistant professor of the Warsaw Electric Energy Institute of the Technological University. I am also a member of the committee on standardization TC 55 and TC 72. I am happy to be able to discuss the standards and present the main idea of these standards and even discuss them together on the Internet.

— I suppose that each of you has an idea about lightning discharges, about the effects of their impact on buildings and people. We understand that lightning flashes are very dangerous for buildings, people, and systems inside this building. These international standards estimate the risk which may arise due to lightning flashes and reduce this risk gradually. This is called risk management, risk assessment methods. There are general criteria of design, installation and use of lightning protection systems for practical reasons. They are divided into 2 groups. The first group relates to lightning protection measures against damage brought to buildings and people inside these buildings. And the second group relates to lightning protection measures which will help to reduce the failure of electric or electronic systems inside these buildings.

— Here you see the general topics and parts of this standard. I mean the first one is general principles, and the second - risk assessment methods, including methodology, risk components which depend on the type of building and type of services offered in these buildings. The third part is the most important part for design of lightning protection measures, because it gives fundamental information how to choose lightning protection measures and how to install it, how to use it, how to work with vertical lightning rods, lightning arresters etc. And, finally, the fourth part. To my mind, it is also very important. This use and installation of lightning protection measures, including data lines, computer, television etc. is the protection of electronic and electric systems.

— It is very interesting to remember that the first part of the standards relates to structures, buildings and also people and the objects inside these buildings. However there are some exceptions, which these IEC standards do not cover in this publication. This standard does not cover railway system; vehicles, water and air transport, as well as offshore installations, high-pressure underground pipes, power transmission line and telecommunications pipelines outside the protected buildings (structures). And these systems should also be protected against lightning, but this topic relates to the other international standards. They are individually studied in every country.

— Here you see the charts in which the possible components of upward and downward lightning are described. On the left - down, on the right -up. Lightning discharges are mainly negative. And very rarely their polarity is positive. As concerns lightning directed upwards, they can be different depending on the type of building's structures.

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External lightning protection. Elements. GALACTIVE active lightning rod Webinar «International electrotechnical standard IEC 62305. General principles», page 2