The conventional Lightning protection system comprise of three fundamental parts: an ordinary lightning conductor bar at a suitable points or areas on the structure to block the lightning, a conductor fitted between the terminal and the grounding system to pass the lightning current into the earth, and the down conductor convey the lightning current into the earth. With legitimate installation, this system is said can give lightning connection point and ways for the lightning current to take after from the connection points into the ground without making any damage to the structure.
The conventional rod and commonly known as franklin rods are the most conventional Lightning protection system with spikes on top in various shape and configuration. Those spikes on top are highly conductive metal and mainly made of copper of stainless steel .These types of devices are passive in nature and act as sacrificial device. The conventional rod act in accordance with standards. However, the major drawbacks of these type of conventional rods is, it only provides small protection zone. Hence, more than one conventional rods are required to give optimum protection to structures with greater in width, length and height.
The examination for further developed terminal was sought after because of the downsides of FR, for example, extremely constrained scope zone, which is conditioned, just by the height and needed protection level and for greater measurement installation number of bars with mesh network must be worked out. As needs be, present day Lightning protection system practices have followed and modified Franklin’s guideline in order to increase the protection zone.
These days, a new approach suggested by scientist and researchers, which is known as Early Streamer Emission (ESE) LP system has been presented in advertising for around ten years. This system as per lab thinks about completed in numerous nations is said to give a more compelling protection against a lightning strike. The inventors and manufacturers had additionally made this as a claim. Nonetheless, solid quantitative data about the relative execution of ESE lightning rod contrasted with Conventional Lightning Rod (CLR) under comparable conditions are as yet inadequate. In this way, the adequacy of these advancements still stays open to being researched more.
ESE types of non-conventional terminals are available in the market in different shapes and configurations. Figure shows few examples of nonconventional lightning rods (such as ESE type of terminal, Dynasphere and DAS) that are manufactured by different manufacturers.
Nowadays Non-Conventional terminals are widely accessible in global market in various shapes and designs. Figure …. shows few types of nonconventional lightning rods, (such as ESE sort of terminal, Dynasphere and DAS) that are fabricated by various designers:
2.7 Lightning Parameters
The data about lightning parameters are essential in deciding lightning protection level (LPL) for a lightning protection system (LPS). Lightning current and lightning ground flash density are two key factors in determining lightning protection level. Lightning current is utilized to decide the measurement of lightning protection system since the peak value of the lightning current is identified with impacts of lightning strike. Besides, the gradient of lightning current head influences the induced voltage because of lightning strike. In the meantime, ground flash density is number of lightning flashes to the ground for a unit zone in a unit of time and communicates in term of ground stroke per kilometer square every year.
The magnitude of the lightning current is a critical parameter in planning a lightning protection system despite the fact that total protection against the lightning strike is unpredictable because of high electric potential and quick ascent time of a lightning strike. Lightning protection system will make a way for high lightning current that makes harm to the buildings channels to ground. Basically, there are four lightning protection levels and each of them relates to various estimations of the lighting parameter. The need or requirement for the structure to be ensured will influence by the choice of lightning protection level. The maximum tolerable hazard should constantly more than the risk of harm to the structure because of an immediate lightning strike. The yearly recurrence of the direct lightning strike to the structure, Nd will be utilized to assess the danger of harm to the structure.