The horse stables are used worldwide to keep horses. Their popularity among horse-lovers is understandable since keeping a real big horse is difficult. To provide safety for animals and people, we have to create lightning protection and grounding of the facility. Such facilities are classified as common according to the regulatory documents and do not imply special lightning protection option. However, it is important to preserve the aesthetics of the building. The ZANDZ Technical Center received a request to calculate the lightning protection system for a horse stable in Moscow. Let us continue with more detailed review of our offered solution.
Calculating lightning protection for a horse stable in Moscow
Facility: a horse stable in Moscow
Figure 1. Facility plan.
План кровли - Roof plan
Task: to perform calculations for the lighting protection system for the horse stable in Moscow
Solutions to meet the requirements to the lightning protection system of the horse stable in Moscow:
- The lightning protection is made in accordance with Electrical Installations Code (EIC), Rev. 7, SO 153-34.21.122-2003 "Guidelines for the lightning protection of buildings, structures and industrial infrastructure" (hereinafter referred to as SO) and RD 34.21.122-87 "Guidelines for the lightning protection of buildings and structures" (hereinafter referred to as the RD).
- According to RD, the facility is considered as the 3rd category lightning protection facility. The system reliability shall be at least 0.9.
- Lightning protection of the facility is made using 9 lightning arresters (masts) with a height of 2 m installed on the roof ridge (GL-11521SS) and 23 lightning arresters (masts) with a height of 4 m installed on the holders to the walls (ZZ-201-004), 1 m for the mount and 3 m up.
- A copper-plated steel wire (copper coating thickness of 70 μm min.), d8 mm (GL 11149) is used as a down conductor.
- The down conductors are installed using the holder GL-11564A on the roof ridge, using the holder GL-11747A on the roof pitches, using the holder GL-11703A on the vertical surfaces. The accepted pitch of terminals is 0.8-1.0 m.
- The universal terminal GL-11551A is used to connect rolled products along the length and in joints.
- All metal elements located on the roof must be connected to the main conductor cable with the terminals GL-11545. Stairs, railings, are attached using the terminal-clamp GL-11514N.
- The vertical copper-plated steel electrodes with the length of 3 m are used as the grounding devices at the downdrops of the down conductors. The copper-plated steel strip with a cross-section of 30x4 mm, combining all vertical electrodes is used as a horizontal ground electrode. The distance to the facility foundation is at least 1 m. Strip deepening is 0.5 to 0.7 m.
- According to EIC-7 issue, par.1.7.55 - Grounding devices for protective grounding of electrical installations for buildings and structures and the 2nd and 3rd categories lightning protection of these buildings and structures, as a rule, shall be common.
- If there are concrete-steel constructions, they shall be connected to down conductors/grounding device.
- Connection to the grounding device is carried out using ZZ-005-064 clamps.
Results of the calculation performed using the software developed by the Krzhizhanovsky Energy Institute (OAO ENIN):
lightning discharge density into the ground is 4 strikes/square km per year.
Total number of strikes into the system is 0.052 (once every 19 years).
The total number of breakouts in the system is 0.0053 (once every 189 years).
The probability of a blowout into the system's facilities is 0.1.
System reliability is 0,9.
Ground terminal resistance calculation:
The design resistance of the grounding arrangement is 0,7 ohm.
Figure 2 shows hardware layout.
Table 1 includes the list of required hardware and materials.
Figure 2. Hardware layout for the lightning protection of the horse stable in Moscow
Table 1. List of material requirements.
Do you have any questions about lightning protection of the stable or other facilities? Please, contact the ZANDZ Technical Center!