Guidelines for Grounding and Lightning Protection Equipment
People die every year due to lightning strikes. During a thunderstorm, lightning can deliver up to 200,000 amps of electricity in a matter of seconds. The most important aspect to understand about lightning protection is that not only can direct lightning strikes have devastating effects on people, buildings, and the natural environment, but more often, electronic equipment is damaged by surges caused by remote lightning discharges (caused by lightning). electromagnetic pulse or LEMP) or switching operations in large electrical systems.
To adequately protect themselves, buildings and electronic equipment must use lightning protection and grounding equipment designed and tested according to the best international standards. The international standard for lightning protection is called IEC 62305 – “Protection against Lightning Strike” (also accepted as a national standard by many countries), specifically adopted by the Bureau of Indian Standards as IS IEC 62305, one of its sections explains the lightning protection of building structures without height restrictions System planning, installation, testing and maintenance needs.
Proper design of lightning protection systems (including air terminals, down conductors, earthing) is important to ensure that the building's ability to be protected from lightning strikes and their effects is enhanced. Unfortunately, most buildings today follow systems that do not comply with basic or statutory requirements. Because only a vertical air outlet cannot solve the purpose of building protection, unless the entire building is fully protected using the protection angle method, mesh conductor method or rolling ball method.
Only by doing the following can effective lightning protection be achieved:
protection type
Protection levels based on risk assessment
The product is technically qualified and complies with the latest relevant IEC standards
Part size and dimensions
Terminal location and coverage
Wire routing and connections
Adequate and necessary grounding measures
Properly utilize natural ingredients as downlinks, if applicable.
Design Guidelines: The following design guidelines need to be followed to ensure a safer installation of external LPS.
If possible, down conductors should be installed at every exposed corner of the structure.
The down conductor should form a direct continuation of the air-termination conductor
Straight and vertical so as to provide the shortest and most direct path to the Earth
Loops in down conductors should be avoided, but if this is not possible, distance "s" should be maintained.
Connect down conductors to gutters or downspouts, even if they are covered with insulation.
Multiple connections using different materials are not allowed.
Undersized conductors (unqualified materials mentioned in Table – 5 of IEC 62305-3) should be strictly avoided.
When the distance between the down conductor and the combustible material cannot be guaranteed, the cross section of the down conductor shall not be less than 100 square millimeters.
Electrical isolation between air-termination or downconductors and structural metal parts, metal fittings and internal systems may be achieved by providing a distance "d" between the parts that is greater than the separation distance "s".
S' = (Ki) x {Kc/Km} x L
in:
Ki – depends on selected LPS level
Kc – depends on the lightning current flowing through the down conductor
Km – depends on electrical insulation material
L – Length in meters along the air-termination or downconductor from which the separation distance to the nearest EPB point should be taken into account.
Standards (IEC): The International Electrotechnical Commission develops and publishes international standards for all electrical, electronic and related technologies and is the leading international organization in the field.
IEC 62305 – Lightning Protection is the highest level document that informs lightning protection standards around the world.
UL and CSA are North American certification bodies that are widely followed in the United States, Canada and other parts of the world.
UL 467: Grounding and Bonding Equipment,
UL 96A: Installation Requirements for Lightning Protection Systems and C22 are several important standards in this field.
Bottom line: Grounding and lightning protection systems must be installed to ensure the safety of personnel and protect buildings and electronic equipment from lightning strikes.
