What is Lightning Protection System?
A lightning protection system is a passive means of preventing property damage from the effects of an electrical strike. It works by providing a path of minimum resistance to the electric charge ground generated by the cloud.
Properly installed lightning protection system has four main parts: copper air terminal, copper cable, copper clad ground rods, surgeon suppressor.
Air terminals and simply are usually copper, but sometimes they can be (or must be) aluminum. All air terminals are connected by cables whose minimum two ground rods are buried 10 feet below the grade.
This system then bases the existing ground on both the water pipe and the circuit box. Covers can be attached to breaker boxes to cover the entire electrical system, or they can be placed on separate equipment or electronics.
When most people hear the sound of lightning, they see large ornate rods with heavy wires on the roof and under the side of the old house.
LSV tries to make the lightning protection system as inconsistent as possible. Typically, the only things visible in lightning protection systems are air terminals on chimneys and roofs, 10 “-12” copper rods.
If the system is to be installed in an existing building, every effort has been made to conceal the copper wire. If the copper cable cannot be hidden, the wire will be less noticeable because it is hardworking and changes from glossy orange to dull patina.
Whether a lightning protection system is concealed or exposed to an existing structure during the construction of a new building, the materials used are identical.
Electrical protection systems can be installed in a variety of structures to protect homes, businesses, farm buildings, boats and trees from damage.
There are a number of independent agencies that have issued standards for the installation and design of lightning protection systems.
The three most recognized are the Underwriters Laboratory (UL), the Lightning Protection Institute (LPI), and the National Fire Protection Association (NFPA).
You can contact any organization and request a copy of UL99A, LPI-175 or NFPA-780, respectively, for appropriate detailed information about the standards.
Components of a lightning protection system (LPS)
Electrical rods or ‘air terminals’ are only a small part of the entire electrical protection system. In fact, rods can play the least important role in any system installation. A lightning protection system consists of three main components:
1. Rods or ‘Air Terminals’– Small, vertical protrusions designed to act as a ‘terminal’ for a lightning discharge. Rods are available in different shapes, sizes and designs. Most are topped with long, pointed needles or smooth, polished spheres.
The fantasy of different types of lightning rods, and even the overall necessity of the rods, is the subject of much scientific debate.
2. Conductor Cables: Heavy wires that send lightning from the sticks to the ground. The wires are run at the top and around the edges of the roof, then one or more corners of a building go down to the ground rod (s) below.
3. Ground Rods- Long, dense, heavy rods were buried deep in the earth around protected structures. Conductor cables are attached to these rods to complete a safe path for lightning around any structure.
Conductor cables and ground rods are the most important components of an electrical protection system, serving the main purpose of securing current safely outside any structure.
The “vertical rods” themselves, i.e. the main vertical terminals along the edges of the roof, do not play much of a role in the efficiency of the system. Given a good protection setup, good cable coverage and good grounding, it will still work well enough without air terminals.
How a lightning protection system works
Lightning strikes can choose instead of using any conductor available inside the house or building, except for a designated path to reach the ground. This may include phones, cables or electrical lines, water or gas pipes, or (in the case of steel-framed buildings) structures themselves.
Lightning will usually follow one or more of these paths toward the ground, sometimes jumping through the air through a side flash to reach a better-oriented conductor (see the animation above). As a result, lightning presents several dangers to any home or building:
.Fire- Fire channel contacts, including wood structures or walls and roof insulators, can enter or come in contact with flammable material (near the wood, paper, gas pipes, etc.) of any building.
. Side flashes- Side flashes could jump across rooms, probably injuring him the way he did. They can burn materials like petrol cans in any garage.
. Damage to building materials- Explosive shock waves caused by lightning can scatter walls, pieces of concrete and plaster, and side glass parts.
. Damage to appliances- Televisions, VCRs, microwaves, phones, washers, lamps and anything plugged into a damaged circuit can only be damaged outside of repair. Electronic devices and computers are particularly vulnerable.
Adding security measures does not prevent the strike, but helps it reach the ground in a better and safer way. Air terminals, cables and ground rods together carry large currents away from the structure, preventing fire and damage to most equipment.
Considerable materials are used to create lightning protection systems, so it is prudent to consider carefully which wind terminal will provide the best protection. From Ben Franklin’s statement, the understanding of lightning was based on the historical realization that each lightning rod protects a 45-degree cone.
It is unsatisfactory for long structural protection, as lightning can pass through any building. A modeling system based on a better understanding of lightning termination targets, called the Rolling Sphere Method, was developed by Dr. Tibor Horváth.
It has become the standard by which traditional Texas Franklin rod systems are installed. Understanding how lightning is ‘driven’ requires knowledge. When a leader jumps to the ground with a bolt of lightning bolts, it is a step towards the land near his path.
The maximum distance that can be traveled in each step is called critical distance and is proportional to the electric current. Objects may be hit if they are closer to the leader than this critical distance.
It is standard practice to estimate the radius of the sphere as approximately 46 m near the ground. If an object outside the critical distance is a solid ground-based object at critical distances, it is unlikely to be hit by the leader.
The potential paths of a leader as a sphere traveling from the clouds to the ground can be determined by imagining what is considered safe from lightning. For lightning protection, it is sufficient to consider all possible fields due to touching potential strike points.
To determine the strike points, consider a sphere surrounding the area. At each point, the position of a potential leader is simulated. Lightning is most likely to occur when the sphere touches the ground.
Points that do not cross the sphere and can be touched protected from lightning. Lightning protectors should be placed where they will prevent from touching the structure of the sphere.
Although a weak point in most electric diversion systems is the transport of discharges trapped in the ground from the lightning rod. Lightning rods are usually installed around a flat roof perimeter or at intervals of 6.1 m or 7.6 m with the rooftop, depending on the height of the rod.
When the length of a flat roof is more than 15 m to 15 m, additional air terminals with a spacing of 15 m or less in a rectangular grid pattern will be installed in the middle of the roof.