Lightning rods installed in private houses, with a general view of which can be found in the photo below, reliably protect the structure from a lightning discharge.
If you do not install this structure in a timely manner, it is possible that lightning will hit the flammable parts of the structure and the occurrence of a fire situation. At the same time, lightning rods are used to protect the equipment available in private households from direct lightning strikes and overvoltage. Their presence is in accordance with the requirements of PTEEP. chapter 2.8 is mandatory in rural areas considered hazardous in assessing the thunderstorm situation in the region.
Principle of operation and design features
The principle of operation of a lightning rod is to "catch" a lightning discharge and redirect it through a safe electrical channel directly to the ground. In accordance with its functional purpose and in accordance with the requirements of PUE-7 p. 4.2.137 this device must contain the following mandatory parts (see photo below):
- Receiver (lightning rod).
- Down conductor.
- Grounding device.
Important!The upper point of the receiver pin is selected so that the straight lines lowered from it at an angle of 45 degrees form a cone that covers the entire protected space.
When choosing a lightning rod design, much attention is paid to the material of the roof covering, which can be metal or tiles, slate or wood.
The first option is the most dangerous, and for arranging the receiving part according to GOST R IEC 62561.2 of 2014 a steel pin with a length of at least 1.0-1.5 meters is required. A pin structure can be installed on the tiles, as well as a catcher in the form of a wire mesh fixed on insulators on the roof surface. For slate and wood covering, a "recumbent" structure is more suitable, which is a steel cable stretched on insulating posts along the ridge of the roof.
How to check the performance of a lightning rod?
The efficiency of a lightning rod cannot be verified by its action in a thunderstorm. Its performance is checked and maintained through constant inspections and elimination of detected faults. At the same time, special attention is paid to the quality of connections and contacts, as well as to the condition of the descents (down conductors).
Technical measures for monitoring the condition of the lightning rod include the following mandatory procedures:
- every six months - visual inspection of open elements of the protective system, including the lightning rod, current descents and the ground loop (photo below):
- exactly the same inspection, carried out with a partial opening of the soil in suspicious places (every 12 years);
- measurement of contact resistance at the points of connection of individual elements of the system.
Testing activities are carried out by specialists from special services (testing laboratories), with whom a contract is concluded for the maintenance of a private protective installation. Based on the test results, an act of admissibility of its further operation is drawn up.