Lightning Protection Testing

It is a British and European Standards requirement that all lightning protection systems are tested and inspected annually.

The lightning protection standard (BS EN 62305-1:2006 Protection against Lightning: General Principles) states that:

Tests should be repeated at fixed intervals, preferably not exceeding 12 months; it may be advantageous to choose a period slightly shorter than 12 months in order to vary the seasons in which tests are made.

This advice is given because earth resistance readings do not simply increase annually, they will invariably rise in summer months as the sub-strata (earth) dries out.

In addition to checking the earth resistance it is also important for a fully qualified and experienced lightning conductor engineer to check that all joints and bonds are not corroded and still have electrical continuity along with full survey of the roof / air termination.

The annual maintenance of a lightning protection systems is very important. An air termination system is a ‘capture mechanism’ so if there was a lightning strike or static electricity in the vicinity of a poorly maintained system or a defective earth installation this could result in devastating effects for the building and its contents.

Poor joints or high earth resistance readings can result in ‘flashover’ to other metal items within or on the structure. This can even take place without a direct strike – all lightning conductors pick up static even if a storm is 4 miles away. It is therefore sensible to ensure that metal objects if applicable are bonded to the lightning conductor system to prevent flashover taking place.

Testing, inspection and certification for Lightning Protection is not prohibitively expensive – but this will depend on the configuration of the building and on the distance travelled by the engineer. A Certificate of Compliance to BS EN 62305 is effective for a 12 month period, much like an MOT on a motor vehicle, and is proof of a regular maintenance programme. This may help when dealing with insurance companies in the event of damage caused by a lighting strike.

This is a unique website which will require a more modern browser to work!

Please upgrade today!