In Russia, children's and youth sports schools appeared in 1930s. Since then, children's and youth sports schools have become more than a place for inclusion of children into sports but a place for training future champions.
Modern regulatory documents contain the requirements and instructions to protect facilities considering their specifics and possible consequences of the lightning strike. Thus, according to SO 153-34.21.122-2003 "Guidelines for Mounting Lightning Protection for Buildings, Structures, and Industrial Utilities" (hereinafter, SO), schools, including children's and youth sports schools, are classified as conventional facilities. According to SO, the lightning strike may cause failure in power supply and fire alarm systems operations. RD 34.21.122-87 "Guidelines for Lightning Protection of Buildings and Structures" (hereinafter, RD) classifies schools as Category III facilities in terms of lightning protection, determines the protection zone type as Zone B, and comprises the following requirements:
Buildings and structures classified as Category III in terms of lightning protection are to be protected from direct lightning strikes and high potential through above-ground (overhead) metal utilities.
In 2022, the ZANDZ.com Technical Center performed a calculation of the lightning protection system for the children's and youth sports school in the Leningrad Region.
Protection of buildings against lightning strikes is provided by using lightning arresters. Lightning arrester is a device that is elevated over the protected facility through which the lightning current goes into the ground bypassing the protected facility. It consists of a lightning rod that accepts the lightning discharge directly, a current collector, and a grounding electrode.
A set of arrangements ensuring compliance with the lightning protection requirements is based on the following solutions:
- 2 x 10 m lightning rods are mounted by their attachment to the wall. It is taken into account that 2 m of the height of lightning rod are necessary for mounting;
- mounting of 6 x 7 m high lightning rods is carried out by attachment to the wall. It is taken into account that 1.5 m of the height of lightning rod is necessary for mounting;
- Lightning rods are interconnected to arrange two current collectors using galvanized steel wire D = 8 mm from each lightning rod. The current collectors are attached (with mounting step 0.6-1 m):
- on the slopes of the roof using clamps GL-11747A;
- to the walls using clamps GL-11703A.
- connection and branching of current collectors are made using clamps GL-11551А.
A set of measures to ensure the requirements for the grounding arrangement is based on the following solutions:
- mounting of a grounding arrangement consisting of a horizontal electrode (galvanized steel strip with cross-section of 4 x 30 mm), depth 0.5 m, distance to the foundation 1 m;
- according to the item 2.13 of RD, in this case, there is no need to mount vertical grounding electrodes; horizontal electrodes are sufficient enough:
Reinforced concrete foundations of buildings and structures are to be used as grounding electrodes to protect against direct lightning strikes in all possible cases. In case of presence of a lightning grid or a metal roof, an external circuit with the following design is installed along the building or structure: in soils having resistivity 500 < ρ ≤ 1000 Ohm·m, with building area over 900 m2, it is sufficient enough to create a circuit made of horizontal electrodes only.
- horizontal electrodes are interconnected using clamps ZZ-005-064;
- current collector is connected to the output of the galvanized ground strip using control clamp GL-11562A;
- the design of the grounding arrangement conforms to the item 1.7.55 of the EIC. Grounding arrangements for protective grounding and grounding for lightning protection are common.
The location of the elements of the lightning protection system and the grounding arrangement is shown in a drawing in a separate file. The indicated protection zone corresponds to zone B according to RD.
Calculation of protection zones of repeated lightning arresters is performed according to the items 2.2 and 3 of the Appendix 3 to RD 34.21.122-87 for the zone B. The protection zone of the repeated lightning arresters is defined as a protection zone of the pairs of adjacent lightning arresters. Taking into account that the distance between the lightning arresters is greater than the height but lower than six heights of lightning rods, we can use the respective set of formulas:
The lightning protection system for the children's and youth sports school, drawing
(click to view the full image)
Зона защиты Б РД 34.21.122-87 на отм. +9.600 Protection zone B RD 34.21.122-87 at elev. + 9.600
Зона защиты БРД 34.21.122-87 Protection zone B RD 34.21.122-87
Зона защиты Б РД 34.21.122-87 на отм +14.400 Protection zone B RD 34.21.122-87 at elev. +14.400
Система молниезащиты детско-юношеской спортивной школы, чертеж (кликните, чтобы открыть полное изображение) The lightning protection system for the children's and youth sports school, drawing (click to view full image)
- стержневой молниеприемник; - lightning rod;
- горизонтальный заземлитель; - horizontal grounding electrode;
- токоотвод по кровле; - current collector on the roof;
- токоотвод по стене; - current collector along the wall;
- зажим для подключения проводника (ZZ-005-064); - clamp for connecting wire (ZZ-005-064);
- зажим для соединения токоотводов (GL-11551A); - clamp for connecting current collectors (GL-11551A);
- зажим контрольный (проволока + полоса) (GL-11562A) - control clamp (wire + bar) (GL-11562A)
List of required materials
Do you have any questions about lightning protection for the cadet school or other facilities? Please, contact the ZANDZ Technical Center!