LIGHTNING PROTECTION OF A DEMO CENTER

ZANDZ Technical Center received a request for lightning protection of a demo center. The building is located in an open area, therefore, despite the small size, it must be protected from lightning.

We chose a combinedr solution for lightning protection of the demo center. A mesh with the size of the cells of not more than 12 m is laid on the roof of the building. In the middle of one of the walls there is a chimney of a gas boiler, it was decided to protect it with two rod lightning rods.

This combination of different lightning protection methods allows you to get a flexible solution, while guaranteeing high reliability. Find out more from the news text.

Task

To calculate lightning protection of a demo center

Solution

Calculations of lightning protection are made in accordance with the following documents:

1. "Electric Installation Code" EIC 7th ed. (hereinafter - EIC).
2. "Instructions for organization of lightning protection of buildings, structures and industrial communications" IS 153-34.21.122-2003 (hereinafter IS).
3. "Instructions for lightning protection of buildings and structures" AD 34.21.122-87 (hereinafter - AD).

Lightning arresters are used for protection of structures from lightning strikes. A lightning arrester usually consists of a lightning rod, intercepting the lightning strike, a down conductor and a ground electrode. All these elements allow to safely drain lightning current into the ground without a damage for the protected object.

Description of the external lightning protection system of the demo center

The set of measures to provide the required lightning protection is offered by the following solutions:

1. The installation of a lightning mesh made of galvanized steel wire with the diameter of 8 mm with mesh sizes of not more than 12x12 m is being carried out.
2. Installation of 2 rods 4 m high, fixed to the wall, is carried out It is taken into account that 0,7 m of the lightning rods height is used for fixation. Lightning rods protect the respiratory pipe of the gas boiler.
3. Lightning arresters are also interconnected for the arrangment of two down conductors from each lightning arrester with the help of galvanized steel wire 8 mm in diameter.
4. Fixation of down conductors is performed (installation distance 0.6-1 m):
   • to the wall – with a GL-11703A clamp;
   • on the roof – with GL-11747A clamp;
5. Connection and branching of down conductors is carried out with the help of GL-11551А clamps.

The set of measures on the provision of the necessary requirements to the grounding device is presented by the following solutions:

1. A horizontal ground electrode is laid around the building. Ground electrode is made of corrosion-resistant steel galvanized tape with the cross section of 30* 4mm, burial depth 0,5 m and the distance to the building walls 1 m.
2. In places of the down drops of down conductors, four vertical electrodes 3 m in length are installed.
3. Interconnection of horizontal electrodes is carried out by using ZZ-005-064 clamp.
4. The down conductor is connected to the copper-bonded tape protruding from the ground with the help of GL-11562A clamp.

The layout of elements in the lightning protection system and the grounding device is shown in Figure 1.

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