Recently, the ZANDZ Technical Center received the task of calculating the lightning protection of a loading and unloading rack, ensuring a system reliability of at least 0.95. Our technical experts offered a solution, which we are sharing with you.

Figure 1 - Plan of the object.

Buildings are protected against lightning strikes using freestanding lightning rods.

1. Lightning protection is carried out in accordance with EIC 7th edition., IS 153-34.21.122-2003 "Instructions for lightning protection of buildings, structures and industrial communications" (hereinafter IS) and AD 34.21.122-87 "Instructions for lightning protection of buildings and structures" (hereinafter AD).

2. The object refers to category 2 of lightning protection. System reliability must be not less than 0,95.

3. Lightning protection of the object is made with the help of 2 vertical free-standing air-terminal masts 20 m high (ZZ-201-020).

4. Installation of a grounding device for each mast, consisting of 2 vertical electrodes with a length of 3 m, connected by a horizontal electrode (copper bonded tape of 30x4 mm). The distance from the horizontal electrode to the foundation of the building is not less than 1 m, the laying depth is 0.5 - 0.7 meters;

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

Density of lightning strikes into the ground - 4 strikes / sq. km per year;

The total number of strikes into the system - 0.075 (once in 13 years);

The total number of breakthroughs is 0.0034 (every 294 years);

System reliability - 0.955;

Probability of a breakthrough into all the system objects - 0.045.

Figure 2 shows the arrangement of equipment.

Table 1 gives the list of the required equipment and materials.

условные обозначения – Type Codes
Молниеприемник мачта высотой 20 м – Air-terminal mast 20 m
Электрод - Electrode
Полоса омедненная стальная сечением 30 на 4 – Copper bonded steep tape with the cross section of 30 * 4mm