We have many times told about the importance of reliable lightning protection in hotels, health centers, sports complexes and other crowded places. At the end of last year, our partner, Company EcoAsk , IE Kosarev S.V, sent a request to the ZANDZ Technical Center with a request to calculate lightning protection system for one of such facilities - the Park-hotel "Sofrino" recreation complex in the Moscow Region. Our experts fulfilled this task. Moreover - lightning protection is already mounted at the facility. Let's look at the solution we offered and what the elements of the finished system look like.
- object: park-hotel "Sofrino";
- existing grounding device - circuit;
- location of the object: Moscow region
Calculate lightning protection system for a hotel using free-standing air terminal masts.
Lightning protection is carried out in accordance with 153-34.21.122-2003 "Instructions for lightning protection of buildings, structures and industrial communications" and AD 34.21.122-87 "Instructions for lightning protection of buildings and structures".
The object refers to the III category of lightning protection. System reliability must be not less than 0,9..
The set of measures to provide the required lightning protection is offered by the following solutions:
- Lightning protection of the object is made in the form of a lightning protection mesh using galvanized steel wire with a diameter of 8 mm (ZZ-502-008). All towering objects (mines, engines) above the roof are protected by air terminals-masts with a height of 4 m on three concrete bases (GL-21121).
- To extend the life of the lightning rod, it is recommended to disassemble the mast structure during the non-thunderstorm period.
- Installation of down conductors is carried out with the help of clamp GL-11711 on the roof, GL-11703А -on vertial surfaces. Down conducts are lowered over rainwater downpipes using GL-11514. Distance between the clamps- from 0.8 up to 1.0 meter.
- To connect rolled metal over the length and in the mesh nodes, a universal clamp GL-11551A L-11551A is used.
- All metal elements, placed on the roof must be connected to the down conductor with the help of clamps GL-11545. Stairs and hand railings are connected with the help of a clamp-bridge GL-11514.
- The existing grounding device is made in accordance with AD 34.21.122-87, clause 2.26.
- Connection to the grounding device is carried out with the help of clamps ZZ-005-064.
- In accordance with the EIC-7 ed., p.1.7.55 - Grounding devices for protective grounding of electrical installations of buildings and structures and lightning protection of the 2nd and 3rd categories of these buildings and structures, as a rule, should be common.
Results of the calculation carried out with the software developed by the OJSC "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 is - 0.11 (once in 9 years);
The total number of breakthroughs is 0.0066 (every 152 years);
Probability of a breakthrough into all the system objects - 0.06;
The reliability of the system is 0.94.
Location of equipment is shown in figure 1.
Figure 1 - Location of equipment.
In the photo below - lightning protection elements installed on the roof of the hotel:
In the background there is an air-terminal mast on three concrete bases 4 m high. In the foreground there is a galvanized down conductor 8 mm in diameter on concrete holders
The list of equipment and necessary materials used during installation are given in table 1.
Table 1 - List of material needs.
|№||Figure||Product item||Name||Quantity, pcs.|
|1.||GL-21121||GALMAR Air terminal mast (4.0 m on 3 concrete foundations; one-stage catenary wire support; galvanized steel)||5|
|2.||ZZ-502-008-125||ZANDZ steel galvanized wire (D 8 mm / S 50mm²; coil of 125 м)||7|
|3.||GL-11551A||GALMAR Clamp for connecting down conductors (painted galvanized steel)||150|
|4.||GL-11703A||GALMAR Clamp to the facade for down conductor with its elevation above the clamp to 15 mm (painted galvanized steel)||360|
|5.||GL-11711||GALMAR Clamp on a flat roof for the down conductor (plastic, concrete)||515|
|6.||GL-11545A||GALMAR Clamp on the gutter for a down conductor (painted galvanized steel)||60|
|7.||GL-11514||GALMAR Clamp-bridge on a gutter for down conductor (tinned copper)||30|
Do you have questions or you need to calculate lightning protection systen for hotels? Send your request to firstname.lastname@example.org.