As lightning protection, earthing and maintenance specialists, Lightning Strike installs systems that comply with NFC 17 102 and BS EN 62305 standards and we provide electrical services compliant with earthing standard BS 7430 1998.
The performance objective of a lightning protection system is to provide an aerial and a path to safely conduct a direct strike to earth. Every component of the system must be compliant with NFC 17 102 and BS EN 62305.

All our work is completed by fully competent operatives and in accordance with the Health and Safety at Work Act 1974.

The main components of a design comprise the risk assessment, a lightning protection efficiency statement for insurers and the calculation for the radius of protection. A mathematical calculation is used to accurately estimate the radius of protection (Rp) and the 'umbrella of protection' (NF C 17-102).

The radius of protection is provided by the ESE product and its relevant performance standard NF C 17-102 (2011) and is used in conjunction with the common elements of IEC / EN 62305. With the level assigned, the protective umbrella (Rp) is calculated in accordance with the ESE product and its performance specification.

In simple terms, a radius of protection table can be drawn up, detailing the corresponding efficiencies (IEC/EN 62305) and providing the Rp at each level for each SafeStrike device at every height (in metres) above the main roof line.

Why Safe Strike ESE?

Lightning Strike uses the Safe Strike ESE because of its numerous benefits, which include a low carbon footprint and cheaper installation and maintenance costs. There are other ESE devices on the market, but we always recommend the Safe Strike ESE device.


An Early Streamer Emitting (ESE) device is similar to a conventional lightning rod and attracts lightning. The system is an air terminal network, consisting of a blunt rod and a cylindrical body. It activates when there is a rise in the electric field.
The body comprises two components: the capacitator accumulates energy from the natural build-up of the electrical field and the triggered device safely releases the stored energy.
The system specifications of the air termination network comprise a Safe Strike S35 ESE unit, serial number MN18, installed to the main chimney. It is bonded directly to the steel work of the chimney, with standoff insulators and a standard stainless-steel bracket.
The Safe Strike ESE gives a 57-metre radius of protection. Down tape conductors utilise the metal chimney as the path to earth. Two cross bonds span from the Safe Strike elevation pole to the chimney’s steel work. The ESE is normally installed at the highest point of the structure, or at the centre.
The radius of protection is calculated in accordance with standard NF C 17-102. The calculations must be in line with the mathematical standards of BS EN 62305 (protection against lightning).
Test points comprise two A-clamps within the inspection pits and the earth termination comprises two 3.6mm x 16mm earth electrodes within the inspection pits. ESE devices must pass a number of tests including the marking test, dimension test, electric current tolerance test and effectiveness test.


The ESE is usually installed at the highest point or at the centre of the structure. To ensure comprehensive protection, the Radius of Protection (RP) must be calculated in accordance with standard NF C 17-102 and in line with the mathematical modelling used in BS EN 62305 (protection against lightning).


All ESE devices should pass the following tests:

  • Marking test
  • Dimension test
  • Electric current tolerance test
  • Effectiveness



Our ESE device is created in accordance with the French National Standard NF C 17-102 (protection against lightning – early streamer emission lightning protection).
The advantages of using Safe Strike ESE include:

  • Low carbon footprint
  • Cheaper installation and maintenance

Although you could consider using other early streamer emitting devices, such as the Helita Pulsar lightning protection system, we would always recommend installing the Safe Strike ESE device.
With any enquiries, please call 01158 752 686 or 07581 266 493. Alternatively you can email us at

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Southwark Council

British Gas


Southwark Council


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