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LIGHTNING PROTECTION OF TRUCK PARKING

Storage of highly inflammable liquids (HIL) must always be accompanied by serious safety measures, in particular, an external lightning protection system is required. A direct lightning strike can result in a fire or even explosion, which does not preclude damage to the surrounding area.

LIGHTNING PROTECTION OF TRUCK PARKING

The ZANDZ Technical Center received a request for the calculation of grounding and lightning protection systems for the parking (storage) of trucks with HIL. Let's consider what solution was offered by our technical experts.

 

Initial data:

  • parking
  • object height: 9.5 m;
  • platform dimensions: 117 mx 32 m;
  • site height in front of the facility: 4.5 m;
  • dimensions of the site in front of the facility: 117 mx 6 m;
  • soil resistivity - 1000 Ohm * m;
  • make the grounding device of galvanized steel.

 

Task:

  • calculate the external lightning protection system of the parking lot and the site in front of it;
  • the facility must be estimated for lightning protection category I;
  • calculate grounding device with the resistance of not more than 30 ohm

 

Solution:

Lightning protection and grounding of the parking are performed in accordance with:

 

The object refers to category I of lightning protection. The reliability of the lightning protection system should be at least 0.99.

 

The set of measures for the implementation of lightning protection and grounding systems for truck parking:

  1. Cable lightning protection system is used as a lightning rod. The cable is stretched on supports 16 m high. The cable sag is up to 2 m.
  2. According to AD.34.21.122-87, clause 2.3 - the distance from the support to the protected object must be at least 4 m.
  3. According to РД.34.21.122-87, п.2.4 - the distance from the cable to the protected object must be at least 4 m.
  4. Galvanized steel electrodes 3 m long are used as a vertical ground electrode, the distance between the electrodes is not less than 6 m. A galvanized steel tape of 30x4 mm section, uniting vertical electrodes, is used as a horizontal ground electrode. The distance to the object foundation- not less than 1 m. Burial depth of the tape 0,5-0,7 m.
  5. The calculated value of the resistance of the grounding device is 29,83 Ohms.
  6. Connection to the grounding device is carried out using И-ЗСПр-Ц clamps


Results of the calculation carried out with the software developed by the OJSC "Energy Institute to the name of G.M. Krzhizhanovsky (JSC "ENIN"):

  • the density of lightning strikes into the ground - 4 strikes / sq. km per year;
  • the total number of strikes into the system - 0.11.
  • the total number of breakthroughs is 0.000067.
  • probability of breakthrough into all the system objects - 0.00058.
  • system reliability - 0.99942
  • the average time between lightning strikes into the system (years): 9
  • average time between the breakthroughs, bypassing the protection (years): 14925.

 

Grounding device resistance calculation:

The design resistance of the grounding device is 29,83 Ohms, which is less than the required resistance of 30 Ohm.

 

The layout of the equipment is shown in Fig.1.

lightning protection of truck parking

Figure 1 - lightning protection and grounding system.

Условные обозначения – Type codes
Опора тросовой молниезащиты высотой 16 м – Catenary wire lightning protection support 16 m high
Полоса стальная оцинкованная сечением – steel galvanized tape with the cross section of 30* 4 mm
Зажим для подключения проводника –clamp for connecting conductor
Вертикальный заземлитель длиной 3 м – vertical ground electrode 3 m long
Грозозащитный трос – ground wire

The list of required equipment and materials is given in table.1.

 

Table 1 - List of required equipment and materials

Item. Designation Name Qty. Mass, kg Note
1. ZZ-204-116-В7-С9 Cable support of lightning protection 16 m high 4    
2. ZZ-204-001 ZANDZ Galvanized steel ground wire (50 mm2) 260   В метрах
3. ZZ-502-304-52 ZANDZ steel galvanized tape (30*4 mm; coil of 52 m) 2 0,96 В метрах
4. И-С3-ЦГ5/8-30 Hot-dip galvanized steel ground rod IGUR 1.5 m in diameter16 mm 24 2,00  
5. И-МС-Л5/8 IGUR brass coupling sleeve 13 0,082  
6. И-Н-С-5/8 IGUR tip for difficult soils 12 0,05  
7. ZZ-004-060 ZANDZ Driving head for a jackhammer 5 0,09  
8. И-ЗСПр-Ц IGUR clip universal cross profile clamp made of galvanized steel for connection of grounding elements (rod, tape) 12 0,4  
9. ZZ-006-000 ZANDZ Conductive grease 2 0,10  
10. ZZ-007-030 ZANDZ Waterproof tape 4 0,40  
11. И-НП-SDS IGUR header for air pick hammer 1 0,40  

Do you have questions or need to calculate lightning protection system for truck parking? Send your request to info@zandz.ru.

 

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