# Lightning protection of a sports complex

There are no specific requirements in AD to lightning protection of sport complexes. Everything depends on the object details and customer desires. At our object there is a service platform in the center of the roof. The engineers of the ZANDZ Technical Center considered this detail when they got a task to calculate lightning protection of one of sports complexes.

We offer you to get familiarized with the project details and calculation example:

## Lightning protection of a sports complex calculation

Object: sports complex.

Figure 1 - Plan of the object.

Task: Calculate lightning protection systems for a sports complex.

Protection of buildings and structures against lightning discharges is ensured by lightning rods. A lightning rod is a device rising above the facility that diverts lightning current into the ground without entering the facility. It consists of a lightning rod which directly takes the lightning discharge upon itself, a down conductor and a ground electrode.

Solutions to meet the requirements for a lightning protection system:

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 3 of lightning protection. System reliability must be not less than 0,9.
3. The lightning protection of the object is made with the help of 5 vertical air-terminal masts 2 m high on concrete bases (GL-21521SS) placed on the service platform, 4 vertical air-terminals masts 1,5 m high installed on metal roof snow barriers around the roof perimeter.
4. Copper-bonded steel wire d8 mm is used as down conductor (ZZ-502-008-125).
5. Installation of down conductors is carried out with the help of clamp GL-11545A - on the service platform, GL-11514N -on the rainwater down pipe for down conductor down drop.  Distance between the clamps- from 0.8 up to 1.0 meter.
6. A universal clamp GL-11551A is used for connecting the mill products along the length and in the nods.
7. All metal elements placed on the roof must be connected to the down conductor with the help of clamps GL-11545A. Stairs, railings are connected with the help of a clamp GL-11514N.
8. A reinforced concrete structure of the building is used as a ground electrode system.
9. Connection to the grounding device is carried out with the help of clamps ZZ-005-064.

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 - 0,46 (once in 22 years);

The total number of breakthroughs is 0.0042 (once in 238 years);

System reliability - 0,908;

Probability of breakthrough into all the system objects - 0.092.

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 1,5 м на анкерах air terminal mast 1,5 m high on anchors молниеприемник мачта высотой 2 м на бетонном основании air terminal mast 2 m high on concrete foundation проволока стальная оцинкованная диаметром 8 мм galvanized 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 опуск токооотвода down conductor downdrop зажим для подключения проводника clamp for connecting conductor

Figure 2 – Equipment layout for lightning protection of a sports complex

Table 1 - List of need in materials.

 № Image Designation Name Qty. 1. GL-21134 GALMAR Air terminal mast (1.5 meters; for vertical surfaces, galvanized steel) 4 2. GL-21131 GALMAR Air terminal-mast on a concrete base (2,0 m; on one concrete base; galvanized steel) 5 3. ZZ-502-008-125 ZANDZ Steel galvanized wire (D 8 mm / S 50 mm²; coil of 125 m) 4 4. GL-11551A GALMAR Clamp for connecting down conductors (painted galvanized steel) 30 5. GL-11545A GALMAR Clamp on the gutter for a down conductor (painted galvanized steel) 370 6. GL-11514N GALMAR clamp to the rainwater downpipe for a down conductor (tape of tinned copper + stainless steel clamp) 80 7. ZZ-005-064 ZANDZ Clamp for connecting conductors (up to 40 mm) 8