Lightning- this is a giant electric discharge in the atmosphere with an average propagation speed of 150 km / s and a current strength of up to 200,000 amperes, and the plasma temperature in lightning reaches 10,000 degrees.

Discharge most often occurs between clouds, but sometimes lightning strikes buildings, tall trees, and very rarely people.

Lightning always hits to the highest point - a house, a tree, etc. When lightning strikes a building, fires, destruction and short circuits occur in the electrical wiring. To avoid all this, . It must be done on the highest buildings or all houses standing separately in open areas or hills.

Lightning protection consists:

• from outside, diverting a direct blow to the ground;
• And internal, which protects electrical wiring and household appliances from overvoltages arising from lightning strikes not only in the house, but also nearby. For example, in overhead power lines (VL).

Surge protection in the house.

For surge protection at substations and overhead lines, arresters and surge arresters are used, and in private houses, an SPD is installed in the electrical panel - a surge protection device.

They are single-phase single-pole for 220 Volt inputs - a phase is connected to the upper contact, and a ground conductor is connected to the lower one. Or bipolar, in which a neutral conductor is also connected to an additional upper contact.
For shields at 380 volts, you will need a 3-phase SPD, in which 3 phases are connected to the top three contacts.

Principle of operation The SPD is simple. When an overvoltage occurs in the phase, their resistance drops and the energy of the pulses is discharged to the ground. At normal voltage, their resistance is quite large.

The SPD in the electrical panel is connected first at the input to the house, and after it the electric meter and automatic machines are already connected.

The connection principle is very simple.- a grounding conductor sits on the contact with the grounding emblem, and a phase (or three for 380 Volts) sits on the phase contact. From the same contact, they go to the counter or introductory machine. It is advisable to leave the wire intact - bend it in half, strip the insulation to the depth of contact and, without cracking, twist. Just be careful not to pinch the insulation.

There are also separate special devices for the protection of television, telephone and computer networks.

Installation and installation of lightning protection.

To protect the house from direct lightning strikes, external lightning protection is used, consisting of:

1. Lightning rod, which takes a direct hit. It is made from a metal rod or rod.
2. Down conductor, diverting the lightning current to the ground. It is made of a copper conductor or steel wire with a diameter of at least 6 millimeters.
3. ground electrode located in the ground. It is made of reinforcement with a diameter of 16 millimeters or more, which is driven into the ground, as deep as possible. Ideally, score a few with a depth of at least 3 meters. Keep in mind, in order to achieve maximum efficiency, the distance between the ground electrodes must be at least their length. Remember that they should be no closer than 5 meters from the entrance to the house, and preferably 7 meters and at least 1.5 meters from the walls of the house. During a thunderstorm, do not come closer than 10 meters to places where grounding conductors are clogged.

Roof lightning protection.

If your house has a metal roof, then it must be connected by welding, bolts with grounding conductors. At the same time, any protruding non-metal elements on the roof, such as a pipe, are equipped with separate lightning rods.

When installing roof lightning protection, the following mandatory rules must be observed:

• Underlayment under the roof must be made of non-combustible material, because when a lightning strikes, the metal heats up to high temperatures with melting, which can cause the roof to ignite.
• All metal elements must have a reliable electrical connection between them. When removing them from each other, use copper jumpers.
• In many cases for a metal roof, it is safer, faster and not expensive to install rod or wire lightning rods.

Installation of lightning protection in a private house.

Outdoor lightning protection easy to do at home. You will need a metal pin for a lightning rod, a copper wire or steel wire for a down conductor, fittings for a grounding conductor, as well as a welding machine, bolts, clamps or brackets for connections and fastening. In the ground, make all connections only by welding with corrosion protection applied to them.