Availability of parking space is an important criteria that defines the market attractiveness of office buildings. The companies increasingly more choose their office according to this criteria. Such facilities should be protected from lightnings and grounded. The facility is conventional according to regulatory documents and does not imply any specific requirements for the lightning protection, but it is important to protect the structure. The ZANDZ Technical Centre has received a request to calculate the lightning protection for the parking space with offices in the Krasnodar Kray. Let us continue with more detailed review of our offered solution.
Calculation of lightning protection for the parking space with offices in the Krasnodar Kray.
Facility: parking space with offices in the Krasnodar Kray.
Figure 1. Facility plan.
Task: To calculate the lightning protection system for the parking space with offices in the Krasnodar Kray
Solutions to meet the requirements to the lightning protection system for the parking space with offices in the Krasnodar Kray are:
- The lightning protection is made in accordance with the Electrical Installations Code (EIC), Rev. 7, SO 153-34.21.122-2003 Guidelines for Lightning Protection of Buildings, Structures, and Industrial Utilities (hereinafter referred to as SO) and RD 34.21.122-87 Guidelines for Lightning Protection of Buildings and Structures (hereinafter referred to as RD).
- According to RD, the facility is considered as the 3rd category lightning protection facility. The system reliability shall be at least 0.9.
- The lightning protection of the facility is implemented using 7 m lightning arresters installed on holder to the walls (ZZ-201-007). 1 m for securing and 6 m upwards.
- A copper-plated steel wire (copper coating thickness of at least 70 μm), d8 mm (GL 11149), is used as a current collector.
- Down conductors are mounted using the GL-11711 clamp on a flat roof, and GL-11703A on vertical surfaces. The accepted pitch of terminals is 0.8-1.0 m.
- The universal terminal GL-11551A is used to connect rolled products along the length and in joints.
- All metal elements located on the roof must be connected to the main conductor cable with the terminals GL-11545. Stairs, railings, are attached using the terminal-clamp GL-11514N.
- Columns at the facility are used as natural current collectors.
- According to item 3.2.2.3 of SO, the facility's foundation and each 20 m by height are banded with current collectors to provide the current collector banding along the perimeter to equalize the potentials.
- d8 mm wire (GL-11149) will be attached to the columns along the facility's perimeter to equalize the potentials. The current collector should be secured by the customer.
- The vertical copper-plated steel electrodes with the length of 3 m are used as the grounding devices at the downdrops of the down conductors. The copper-plated steel strip with a cross-section of 30x4 mm, combining all vertical electrodes is used as a horizontal ground electrode. The distance to the facility foundation is at least 1 m. Strip deepening is 0.5 to 0.7 m.
- According to EIC-7 issue, par.1.7.55, Grounding devices for protective grounding of electrical installations for buildings and structures and the 2nd and 3rd categories lightning protection of these buildings and structures, as a rule, shall be common.
- If there are concrete-steel constructions, they shall be connected to down conductors/grounding device.
- Connection to the grounding arrangement is made through the terminals ZZ-005-064.
Расчет зоны зашиты в соответствии с СО: - Calculation zone according to SO:
Молниеприемники: - Lightning arresters:
Высота конуса согласно СО табл. 3.4: - Cone height according to SO, Table 3.4:
Радиус конуса согласно СО табл. 3.4: - Cone radius according to SO, Table 3.4:
Расстояние между молниеприемниками: - Distance between lightning arresters:
Предельное расстояние между молниепрнемниками согласно СО, табл. 3.6: - Limit distance between lightning arrester according to SO, Table 3.6:
Высота провеса: - Sag height:
Для зоны защиты требуемой надежности радиус горизонтального сечения rcx на высоте hx =24,9 м определяется: - For a protection zone with the required reliability, horizontal cross-section rcx radius at height hx = 24.9 m is defined as follows:
Высота конуса согласно СО табл. 3.4: - Cone height according to SO, Table 3.4:
Радиус конуса согласно СО табл. 3.4: - Cone radius according to SO, Table 3.4:
Расстояние между молниепрнемниками: - Distance between lightning arresters:
Предельное расстояние между молниепрнемниками, согласно СО, табл.3.6: - Limit distance between lightning arresters according to SO, Table 3.6:
м - m
Для зоны защиты требуемой надежности радиус горизонтального сечения rcx на высоте hx =27,9 м определяется: - For a protection zone with the required reliability, horizontal cross-section rcx radius at height hx = 27.9 m is defined as follows:
Ground terminal resistance calculation:
Верт - Vert
Гор - Hor
Ом - Ohm
ЗУ - GA
calculated resistance of the grounding arrangement is 1,8 Ohm.
Figure 2 shows hardware layout.
Table 1 includes the list of required hardware and materials.
Условные обозначения - Legend
- Молниеприемник-мачта высотой 7 м на держателях - Lightning rod 7 m high on holders
- Проволока стальная омедненная диаметром 8 мм - Steel copper-plated wire diam. 8 mm
- Универсальный зажим-соединитель для проволоки - Multi-purpose wire connecting clamp
- Зажим-хомут - Coupler clamp
- полоса стальная омедненная сечением 30 х 4 мм - Steel copper-plated bar 30 x 4 mm
- Зажим для подключения проводника - Conductor connecting clamp
- Опуск токоотвода - Downdrop
- Вертикальный заземлитель длиной 3 м - 3 m vertical grounding electrode
Figure 2. Layout of equipment to provide lightning protection for parking space with offices in the Krasnodar Kray
Table 1. List of required materials.
Do you have any questions about lightning protection for parking spaces or other facilities? Please, contact the ZANDZ Technical Center!
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