1) Protection Radius Theory

Here you will find an explanation on how to read the protection radius table correctly.

The SCHIRTEC E.S.E. Lightning Conductors are in accordance to the NF C 17-102 and similar E.S.E. Standards. The design requirements, protection level calculations and protection radius are obtained from this standard.

Protectionlevel

According to NF C 17-102 Ed. 2.0, the standard protection radius (Rp) of the SCHIRTEC E.S.E. is linked to ∆T, the protection levels I (98%), II (95%), III (90%) or IV (80%) and the height of the SCHIRTEC E.S.E. above the structure to be protected (H, as a minimum 2 m)

The protection level of the object depends on several factors such as:

if the object is inhabited or not

if the object is expolosiv or not,

material of the roof and the roof construction (wood, metall,...)

The more valuable and vulnerable the object is the higher the level of protection needed. e.g. an inhabited house, with a metal roof could be attributed to protection class 1. A telephone pole of low value could attributed to the protection class 4. The safety class can be calculated with our lightning risk program.

h

Installation height, the higher the lightning conductor is installed the greater the protective radius Rp (m)

Rp(m)

Radius protection, we recommend  to install the lightning conductor in a height of 5 to 6 meters because you can then achieve a high level of protection.

Protection Level Calculator

Strike Risk Assessment   Program

Example 1 for S-A: Single-familiy-home; Protection Level 1

Example  2 for S-A: Factoryhall; 150 m x 50m, Protection Level 1

The lightning conductor  S-A has been installed at a height of 4m.The protection radius has to be specified according to NF C 17-102 standard with 63m, the effective protection is bigger, according to our test reports.

There were two lightning conductors S-A installed at a height of 6m. The radii overlap and provide for the entire production facility sufficient protection.The protection radius must be specified according to NF C 17-102 with 79m, the effective protection is bigger, according to our test reports

Protection Radius Table

Rp(m) S-AS (ΔL: 30m) S-DAS (ΔL: 45m) S-A / S-DA (ΔL: 60m)h I II III IV I II III IV I II III IV2 19 22 25 28 25 28 32 36 31 35 39 434 38 44 51 57 51 57 64 72 63 69 75 855 48 55 63 71 63 71 81 89 79 86 97 1076 48 55 64 72 63 71 81 90 79 87 97 1078 49 56 65 73 64 72 82 91 79 87 98 10810 49 57 66 75 64 72 83 92 79 88 99 10920 50 59 71 81 65 74 86 97 80 89 102 11330 50 60 73 85 65 75 89 101 80 90 104 11660 50 60 75 90 65 75 90 105 80 90 105 120

Key:

h: Installation heightI/II/III/IV: ProtectionlevelRp(m): Protectionradius in m

56

Recommendedinstallation height

Early Streamer Emission Lightning Protection

Thunderguard Lightning Protection

The THUNDERGUARD, Early Streamer Emission Systems (ESE) has a larger protection radius when compared to a conventional Franklin rod. The THUNDERGUARD ESE TERMINAL produces an upward streamer quicker than conventional air terminals and attaches the downward leader of the lightning strike in mid air, before it strikes any other object in the vicinity and safely conducts the lighting current to the ground via the down-conductor and the earthing system.

Just before the lightning strike, THUNDERGUARD senses the rapid change in the ambient electric field and produces high voltage pulses that ionises the air particles around the device, generating an upward streamer that intercepts the downward leader of the lightning strike.

Specifications & Standards

Full Specifications & Standards

Full compliance with French Standard NF C17-102.

Outer body made of non-corrosive XL 304 stainless steel making the system fully resistant todynamic power surging and effects of acid rain caused by lightning discharge.

Capturing rod diameter : 25mm

Atmospheric Area Force : 5 – 200 Kv/m

Lightning Conductor weight : 6.2 Kg

Different models with various protection radii available to suit the application.

Thunderguard ESE Terminal

Inline Coupling

Metallic Lower Mast

Downconductor Saddle

Lightning Event Counter

Inspection Pit

Ground Rods

The ESE Principle

The Principle of operation for ESE terminals is to create an upward propagating streamer earlier than conventional air terminals or other objects on the earth. Thunderguard does this by collecting  and storing ground charge during the initial phase of a thunderstorm development.

Once a thunderstorm begins creating downward step leaders, the ambient electric field intensity in the area of the ESE terminal increases. When this electric field intensifies, it triggers the terminal to release the stored ground charge, forming an upward streamer microseconds earlier than other objects in the immediate area.

This development of an upward streamer earlier in time and space ensures that the Thunderguard ESE Terminal will be target of the developing lightning strike. The selection of the Thunderguard model, placement, and mounting height above the protected area all factor into formulas calculating the dimensions of the protection area.

The standard protection radius R of the Thunderguard is linked (according to NF C 17-102 standard) to /_\       T, to the protection levels I, II, III or IV and to the height of the Thunderguard above the protected structure (H, defined by NF C 17-102 as a minimum of 2 m). The NF C 17-102 standard includes four levels of protection. The protection radii of different models of Thunderguard are given in the table. Our experts will suggest the most suitable model after conducting a site survey.

Lightning Event Counter Protection Areas

The lightning event counter is designed to keep a record of all direct lightning strikes on the external lightning protection system . The digital display (6 digits) allows a direct and comfortable reading of the number of lightning events. It requires no external power supply and functions on a lithium battery. Suitable for use with both ESE terminals and conventional lightning protection systems.

Specifications

Current Sensitivity           : 3KA nom. for 8/20us impulse.Operating range               : 3KA min, >150KA max

: Resettable 6 digit LCD counter 8mm numerals.Power source    : Lithium battery 10 years life.Dimensions        : 110mm (w) x 80mm (h) x 66.5mm(d).

            : 90mm x 60mm x M4.

Weight : 0.2kg.