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Example of lightning protection example of a workshop in Omsk

  • 30.05.2019

 

If there are no special requirements or explosive flammable zones, the workshops refer to category III of reliability according to AD.

ZANDZ Technical Center has recently received a task to calculate lightning protection of a workshop. We offered a solution which we will give below.

 

Example of lightning protection of a workshop calculation in Omsk

 

Object: workshop.

план кровли roofing plan

Figure 1 – Plan of the object.

 

Task: Perform calculations of a lighting protection system for a workshop.

 

Protection of buildings from lightning discharges is carried out by using lightning rods located on the roof of the object.

 

Solutions on the provision of requirements to the lightning protection of a workshop:

  1. Lightning protection is carried out in accordance with  EIC 7-th edition, IS 153-34.21.122-2003 «Instruction on arrangement of lightning protection of buildings, structures and industrial communications» (hereinafter IS) and AD 34.21.122-87 «Instruction on arrangement of lightning protection of buildings and structures» (hereinafter AD).
  2. The object refers to the 3d category of lightning protection. System reliability should be not less than 0, 9.
  3. It is necessary to make a grounding device (GD) with the resistance of not more than 4 Ohm.
  4. Ground resistivity taken for calculations - 300 Ohm*m.
  5. The object refers to III category of AD. The system reliability should be not less than 0, 9.
  6. Lightning protection of the object is carried out with the help of 8 air terminals masts 7 m high attached to the wall (ZZ-201-007-3) and 11 air terminals masts 6 m high fixed to the wall (ZZ-201-006-3).
  7. Steel copper bonded wire d8 mm is used as a down conductor (the thickness of the copper bonding is at least 70 mcm (GL-11149).
  8. Installation of down conductors is carried out with the help of holder GL-11703A. The installation pitch for clamps 0,8 - 1,0 m
  9. A universal clamp GL-11551A is used for connection of the rolled metal along the length and in the nods.
  10. All metal elements located on the roof must be connected to the down conductor with the help of clamps GL-11545. Stairs, railings are connected with the help of clamp GL-11514N.
  11. 5 vertical copper-bonded steel electrodes 3 m long are used as a grounding device. A copper-bonded steel tape with the cross-section of 30*4mm uniting all vertical electrodes is used as a horizontal grounding electrode. The distance to the object foundation is not less than 1 m. Deepening of the tape 0,5-0,7 m.
  12. According to EIC 7th edition, p.1.7.55 – Grounding devices of protective grounding of electric installations and structures and lightning protection of the 2 and 3 categories of these buildings and structures, are common, as a rule.
  13. Calculated value of grounding device resistance – 2,63 Ohm.
  14. If there are reinforced concrete structures, they must be connected to down conductors/grounding device.
  15. Connection to the grounding device is carried out with the help of ZZ-005-064 clamps.

 

Calculation of protection zone in accordance with IS:

молниепримник М1-4    lightning rod M1-4
высота конуса согласно СО табл 3.4 cone height according to IS table 3.4
радиус конуса согласно СО табл 3.4 cone radius according to IS table 3.4
расстояние между молниеприемниками distance between lightning rods
предельное расстояние между молниеприемниками, согласно СО, табл 3.6 ultimate distance between lightning rods according to IS, table 3.6
высота провеса vertical clearance
для зоны защиты требуемой надежности радиус горизонтального сечения Rcx на высота Hx = 27, 25 м определяется for protection zone of the required reliability, the radius of the horizontal section Rcx at the height Hx=27,25 is determined as
молниеприемник М5-7 lightning rod M5-7
высота конуса согласно СО табл 3.4  cone height according to IS table 3.4
радиус конуса согласно СО табл 3.4 cone radius according to IS table 3.4
расстояние между молниеприемниками distance between lightning rods
предельное расстояние между молниеприемниками, согласно СО, табл 3.6 ultimate distance between lightning rods according to IS, table 3.6
высота провеса vertical clearance
для зоны защиты требуемой надежности радиус горизонтального сечения Rcx на высота Hx = 23, 78 м определяется for protection zone of the required reliability, the radius of the horizontal section Rcx at the height Hx=23,78 is determined as
молниеприемник М8-11 lightning rod M8-11
высота конуса согласно СО табл 3.4 cone height according to IS table 3.4
радиус конуса согласно СО табл 3.4  cone radius according to IS table 3.4
расстояние между молниеприемниками distance between lightning rods
предельное расстояние между молниеприемниками, согласно СО, табл 3.6 ultimate distance between lightning rods according to IS, table 3.6
высота провеса vertical clearance
для зоны защиты требуемой надежности радиус горизонтального сечения Rcx на высота Hx = 14, 59 м определяется for protection zone of the required reliability, the radius of the horizontal section Rcx at the height Hx=14,59 is determined as
Молниеприемник М16-19 lightning rod M16-19
высота конуса согласно СО табл 3.4 cone height according to IS table 3.4
радиус конуса согласно СО табл 3.4 cone radius according to IS table 3.4
расстояние между молниеприемниками distance between lightning rods
предельное расстояние между молниеприемниками, согласно СО, табл 3.6 ultimate distance between lightning rods according to IS, table 3.6
высота провеса vertical clearance
для зоны защиты требуемой надежности радиус горизонтального сечения Rcx на высота Hx = 12, 84 м определяется for protection zone of the required reliability, the radius of the horizontal section Rcx at the height Hx=12,84 is determined as
расчёт сопротивления заземляющего устройства grounding device resistance calculation

Grounding device resistance calculation

 

Design resistance of the grounding device is 2,63 Ohm.

 

The arrangement of equipment is shown in Figure 2.

Table 1 gives the list of required equipment and materials.

план кровли roofing plan
условные обозначения Type Codes
молниепримник-мачта высотой 7 м air terminal mast 7 m high
молниеприемник-мачта высотой 6 м air terminal mast 6 m high
проволока стальная омедненная диаметром 8 мм copped-bonded steel wire 8 mm in diameter
универсальный зажим соединитель для проволоки universal connector clamp for wire
фальцевая клемма для крепления к металлическим конструкциям folding terminal for fixation to metal structures
зажим-хомут clamp
полоса стальная омедненная сечением 30*4 мм copper-bonded wire with the cross-section of 30* 4mm
зажим для подключения проводника clamp for connecting conductor
опуск токоотвода down conductor down drop
вертикальный заземлитель 3 м vertical ground electrode 3 m

Figure 2 - Layout of equipment for lightning protection of a workshop.

 

Table 1 – List of material needs.

№ Image Marking Name Q-ty.
1. ZZ-201-007-3 ZANDZ air terminal mast vertical 7 m with the set of 2 fixations to the wall (stainless steel) 8
2. ZZ-201-006-3 ZANDZ Air-terminal mast vertical 6 m with the set of 2 fixations to the wall (stainless steel) 11
3. ZZ-202-002 ZANDZ Clamp to lightning rod D42 mm for down conductors (stainless steel) 19
4. GL-11149-50 GALMAR Copper-bonded wire (D 8 mm / S 50 mm²; coil of 50 meters) 16
5. GL-11551A GALMAR Clamp for connection of down conductors (painted galvanized steel) 65
6. GL-11703A GALMAR Clamp to the façade for down conductor with its elevation above the clamp to 15 mm (painted galvanized steel) 800
7. GL-11545A GALMAR Clamp to the gutter for down conductor (painted galvanized steel) 20
8. GL-11514N GALMAR clamp to gutter for down conductor (tape of tinned copper + stainless steel clamp) 20
9. GL-11562A GALMAR Control clamp for connecting down conductors + tape (painted galvanized steel) 5
10. GL-11075-50 GALMAR Copper-bonded tape (30*4 mm / S 120 mm²; coil of 50 meters) 8
11. ZZ-001-065 ZANDZ Copper-bonded threaded grounding rod (D14; 1,5 мm) 10
12. ZZ-002-061 ZANDZ Threaded coupler 6
13. ZZ-003-061 ZANDZ Starting tip 5
14. ZZ-004-060 ZANDZ Guide head for a breaker hammmer 2
15. ZZ-005-064 ZANDZ Clamp for connecting conductor (up to 40 mm) 13
16. ZZ-006-000 ZANDZ Conductive grease 1
17. ZZ-007-030 ZANDZ Hydro-insulation tape 4
18. ZZ-008-000 ZANDZ Breaker hammer tip (SDS max) 1

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