Crucial to the installation of any lightning protection system, lightning conductor testing should also be carried out on existing systems by skilled personnel on a regular basis, using calibrated test equipment, to ensure safety and to comply with the relevant legislation.
What is a lightning conductor and how does it help?
The lightning conductor is the metal rod or wire that is attached to an exposed part of a building or tall structure to divert lightning strikes harmlessly into the ground. If lightning hits the building, it will go through the conductor rather than passing through the building’s structure.
If a bolt of lightning strikes a building where there is no lightning protection, there are potentially disastrous consequences. It could cause structural damage to the building, start a fire, or cause electrocution, leading to injuries or even loss of life.
The lightning rod or conductor is a single component, requiring a connection to earth to function effectively. Conductors are manufactured in different forms including solid, hollow, rounded, pointed and flat strips. They have one common attribute: they are all made of a conductive material, such as aluminium or copper – the most commonly used materials are copper and its alloys.
OUR PROCESS
Inspection
A competent person must visually inspect all lightning protection systems during the installation process, after completion and after any extension or alteration, in order to verify that they are in accordance with the recommendations of the British Standards Code of Practice 6652:1999, BSEN 62305-2011 and NF C 17 102-2011.
Visual inspections should be carried out regularly – at least once every 12 months.
In addition, the mechanical condition of all earth electrodes, conductors, joints and bonds should be checked and the results noted. If it’s not possible to inspect some parts of the system for any reason – such as temporary building works – this should also be noted.
During periodic inspections of the lightning protection system, the bonding of any recently added service should be checked to ensure it’s in accordance with the recommendations of the British Standard.
Testing
Once the installation is complete, or any modification has been fulfilled, checks must be made, and the results recorded in a log book. The inspection will include the resistance to earth of the earth termination – the results of a visual check of system will also be recorded.
If the resistance to earth of the lightning protection system exceeds 10 ohms, the value should be reduced. Again, the test should be repeated at fixed intervals not exceeding 12-month intervals.
Records
Records should be stored at the site, or by the person responsible for the installation’s upkeep. These should include detailed drawings showing the nature, material, dimensions and positions of all component parts of the lightning protection system.
The records must also include the results of soil resistivity testing, providing details of the nature of the sub-soil and any special earthing arrangements, the type and position of the earth rod and whether the test conditions were wet or dry.
The name of the person responsible for the installation’s upkeep must be logged and any alterations. Any additions or repairs to the system must also be recorded.
