The lightning protection of most facilities implies installation of lightning arresters on the roof or walls. However, there are buildings, the structure of which is appropriate to protect themselves against the lightning. We will consider this by the example of the skating rink protection.
The skating rink we are talking about is protected against lightning with the roof having metal frames and binding rafters. With such structure, it is desirable for the metal coating to have an electrical connection with binding rafters, but even without it, the current will anyway penetrate the frames. Thermal insulator and waterproofing will not be barriers; the main requirement to them is their inflammability.
Coupling frames with metal columns allows safely draining the lightning current into the ground. The only artificial element in this lightning protection method for the skating rink will be the grounding device coupling columns in the ground along the perimeter.
Read more details about technical solutions for the skating rink lightning protection.
Task
To calculate the lightning protection and grounding for the skating rink.
Solution
Solutions for the skating rink lightning protection are made according to the following documents:
- "Electrical Installations Code" (hereinafter referred to as the EIC), 7th edition.
- "Instructions for the installation of lightning protection of buildings, structures, and industrial communications" SO 153-34.21.122-2003 (hereinafter referred to as SO).
- "Instructions for mounting the lightning protection of buildings and structures" Working Documentation 34.21.122-87 (hereinafter referred to as the RD).
The lightning arresters are used to protect the buildings against lightning strokes. The lightning arrester consists of an interception rod, intercepting a lightning discharge, the main conductor cable, and the ground electrode. All these elements let us divert lightning current into the ground safely, without any damage to the protected facility.
The terrace is classified as a conventional facility in terms of lightning protection according to SO and to Category 3 according to RD.
Description of the skating rink lightning protection system
A set of arrangements ensuring compliance with the lightning protection requirements is based on the following solutions:
- According to item 2.11 of RD, "Installation of lightning arresters or laying of a lightning protection grid is not required for the buildings and structures with metal frames, provided that in their roofs, incombustible or hardly combustible thermal insulators and waterproofing materials are used".
- As current collectors according to items 1.6 and 2.2 of RD, the metal shell of the building is used (frames and columns) provided that the continuous electrical coupling is present in structural and reinforcement connections with lightning arresters and grounding devices.
A set of measures to ensure the requirements for the grounding arrangement is based on the following solutions:
- Assembly of a grounding arrangement, consisting of a horizontal electrode (galvanized steel strip with a cross-section of 4 x 30 mm), to a depth of 0.5 m, laid along the perimeter of the building at a distance of 1 m from the foundation.
- According to item 2.13 of RD, the circuit without installation of vertical electrodes is sufficient (in soils with the equivalent resistivity not more than 500 Ohm*m with the building area more than 250 sq. m, a circuit is made of horizontal electrodes).
- The connection of horizontal electrodes to each other, as well as to metal columns is carried out using clamp ZZ-005-064.
- The design of the grounding arrangement corresponds to clause 1.7.55 of EIC Grounding arrangements for protective grounding and grounding for lightning discharges are common.
The location of the elements of the lightning protection system and the grounding arrangement is shown in Figure 1.
Условные обозначения - Key
Экспликация помещений - Room layout
Figure 1. Arrangement of the grounding device for a skating rink
Components for lightning protection and grounding of the skating rink
| № | Part number | Name | Quantity, pcs. |
| Grounding arrangement | |||
| 1. | ZZ-005-064 | ZANDZ Conductor connection terminal (up to 40 mm) | 26 |
| 2. | GL-11075-50 | GALMAR Copper-clad strip (30*4 mm / S 120 mm²; 50-meter strip bundle) | 5 |
| 3. | ZZ-007-030 | ZANDZ Waterproofing tape | 6 |
Do you have questions regarding lightning protection and grounding of the skating rink? Please, contact the ZANDZ Technical Center!
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