lighting protection guide

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PROTECTION

GUIDE

LIGHTNING

PrefaceSince its foundation in 1980, theIEC TC81 Lightning Protection of theInternational Electrotechnical Commis-sion (IEC) has drawn up diversestandards for the protection of build-ings from lightning, for the protectionof electronic systems, for risk analysisand for the simulation of the effects oflightning. These standards were com-piled one after the other as they wererequired, and published under differentnumbers with no recognisable system.The standards work therefore becamemore and more unsystematic to the user.In September 2000, the IEC TC81 there-fore decided to introduce a new, clearlyarranged structure for lightning protec-tion standards (series: IEC 62305).Revised and new standards will be inte-grated into this new structure.

The decision of the IEC TC81 to reor-ganise the lightning protectionstandards led the K251 Committee ofthe German Commission for Electrical,Electronic and Information Technologiesof DIN and VDE (DKE), which is respon-sible for Germany, to decide toreorganise the German lightning pro-tection standards. This project wasrealised in December 2002 with the pub-lication of a completely new series ofVDE prestandards for lightning protec-tion, and the simultaneous withdrawalof all previously published lightning pro-tection standards, prestandards anddraft standards. The publication of thenew series of prestandards was under-taken in close collaboration with theCommittee for Lightning Protection andLightning Research (ABB of VDE) andthe Association of German LightningProtection Companies (VDB e. V.).

In the future, contractors will have tofollow the prestandards of the VDEV 0185 series when signing new con-tracts for the design and installation oflightning protection systems, in orderto work in accordance with the State ofthe Art.For this to be possible, the contractormust familiarise himself with the con-tents of the new lightning protectionprestandards.

With this completely revised LIGHTNINGPROTECTION GUIDE, we would like tosupport you as the specialists in thisfield, regardless of whether you areinvolved in design or executing, inbecoming familiar with the new series ofprestandards.

DEHN + SHNE

www.dehn.de LIGHTNING PROTECTION GUIDE 1

Aerial photo of DEHN + SHNE August 2003

Revised: May 2004

We reserve the right to introducechanges in performance, dimensionsand materials in the course of technicalprogress. The figures are shown without obliga-tion. Errors and omissions excepted.Reproduction in any form whatsoeveris forbidden without our permission.

Publication No. DS702/E/2004

www.dehn.de2 LIGHTNING PROTECTION GUIDE


ContentsPreface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1

Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3

General Key to Symbols used in Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6

1. State of the Art for the installation of lightning protection systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7

1.1 Installation standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7

1.2 Work contracts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8

1.3 Product standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9

2. Characteristics of lightning current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11

2.1 Lightning discharge and temporal development of the lightning current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11

2.2 Peak value of the lightning current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13

2.3 Steepness of lightning current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15

2.4 Charge of lightning current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15

2.5 Specific energy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17

2.6 Assignment of lightning current parameters to lightning protection levels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18

3. Designing a lightning protection system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19

3.1 Requirement for a lightning protection system legal requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19

3.2 Assessment of the risk of damage and selection of protective components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23

3.2.1 Risk management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23

3.2.2 Fundamentals of risk assessment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25

3.2.3 Frequency of lightning strokes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25

3.2.4 Damage probabilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27

3.2.5 Types of damage and causes of damage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28

3.2.6 Damage factor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28

3.2.7 Relevant risk components for different lightning strokes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30

3.2.8 Acceptable risk of lightning damage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31

3.2.9 Choice of lightning protection measures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31

3.2.10 Design aids . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32

3.2.11 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32

3.3 Inspection and maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32

3.3.1 Types of inspection and qualification of the inspectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32

3.3.2 Inspection measures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33

3.3.3 Documentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34

3.3.4 Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34

4. Lightning protection system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35

5. External lightning protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37

5.1 Air-termination systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37

5.1.1 Installation methods and types of air-termination systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37

5.1.2 Air-termination systems for structures with gable roofs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .44

5.1.3 Air-termination systems for flat-roofed structures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45

5.1.4 Air-termination systems on metal roofs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .47

5.1.5 Principle of an air-termination system for structures with thatched roof . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .49

5.1.6 Walkable and trafficable roofs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50

5.1.7 Air-termination system for planted and flat roofs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .51

5.1.8 Isolated air-termination systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .52

5.1.9 Air-termination system for steeples and churches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .54

5.1.10 Air-termination systems for wind turbines (WT) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .55

5.1.11 Wind load stresses on lightning protection air-termination rods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .55

5.2 Down-conductor system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .59

5.2.1 Determination of the number of down conductors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .59

5.2.2 Down-conductor system for a non-isolated lightning protection system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .59


5.2.2.1 Installation of down-conductor systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .60

5.2.2.2 Natural components of a down-conductor system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .61

5.2.2.3 Measuring points . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .62

5.2.2.4 Internal down-conductor systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .62

5.2.2.5 Courtyards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .62

5.2.3 Down conductors of an isolated external lightning protection system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .63

5.2.4 High-voltage resistant, isolated down-conductor system HVIconductor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .63

5.2.4.1 Installation of a HVI isolated down conductor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .64

5.2.4.2 Installation example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .64

5.2.4.3 Project example: Training and residential building . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .65

5.2.4.4 Separation distance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .67

5.3 Materials and minimum dimensions for air-termination conductors and down conductors . . . . . . . . . . . . . . . . . . .68

5.4 Assembly dimensions for air-termination and down-conductor systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .69

5.4.1 Change in length of metal wires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .70

5.4.2 External lightning protection system for a residential house . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .71

5.4.3 Application tips for mounting roof conductor holders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .73

5.5 Earth-termination systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .75

5.5.1 Earth-termination systems in accordance with DIN V VDE V 0185-3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .81

5.5.2 Earth-termination systems, foundation earthing electrodes and foundation earthing electrodes for special structural measures .82

5.5.3 Earth rod Earthing electrode Type B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .86

5.5.4 Earth rods Earthing electrodes Type A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .86

5.5.5 Earthing electrodes in rocky ground . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .87

5.5.6 Intermeshing of earth-termination systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .87

5.5.7 Corrosion of earthing electrodes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .88

5.5.7.1 Earth-termination systems with particular consideration of corrosion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .88

5.5.7.2 Formation of voltaic cells, corrosion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .89

5.5.7.3 Choice of earthing electrode materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .91

5.5.7.4 Combination of earthing electrodes made of different materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .92

5.5.7.5 Other anticorrosion measures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .92

5.5.8 Materials and minimum dimensions for earthing electrodes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .93

5.6 Electrical isolation of the external lightning protection system Separation distance . . . . . . . . . . . . . . . . . . . . . . . .93

5.7 Step and contact voltages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .98

6. Internal lightning protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .101

6.1 Equipotential bonding for metal installations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .101

6.2 Equipotential bonding for low voltage electrical power installations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .103

6.3 Equipotential bonding for information technology installations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .104

7. Protection of electrical and electronic systems against LEMP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .107

7.1 Lightning protection zones concept . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .107

7.2 LEMP protection management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .108

7.3 Calculation of the magnetic shielding attenuation of building/room shielding . . . . . . . . . . . . . . . . . . . . . . . . . . . .109

7.3.1 Cable shielding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .112

7.4 Equipotential bonding network . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .114

7.5 Equipotential bonding on the boundary of LPZ 0A and LPZ 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .116

7.5.1 Equipotential bonding for metal installations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .116

7.5.2 Equipotential bonding for power supply installations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .116

7.5.3 Equipotential bonding for information technology installations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .118

7.6 Equipotential bonding at the boundary of LPZ 0A and LPZ 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .119




7.7 Equipotential bonding on the boundary of LPZ 1 and LPZ 2 and higher . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .120




7.8 Coordination of the protective measures at various LPZ boundaries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .122

7.8.1 Power supply installations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .122

7.8.2 IT installations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .122

7.9 Inspection and maintenance of the LEMP protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .123

8. Selection and installation of surge protective devices (SPDs) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .125

8.1 Power supply systems (within the scope of the lightning protection zones concept according to DIN V VDE V 0185-4) .125

8.1.1 Technical characteristics of SPDs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .126

8.1.2 Use of SPDs in various systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .127

8.1.3 Use of SPDs in TN Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .129

8.1.4 Use of SPDs in TT systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .134

8.1.5 Use of SPDs in IT systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .138

8.1.6 Rating the lengths of the connecting leads for SPDs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .140

8.1.7 Rating of the cross-sectional areas and the backup protection of surge protective devices . . . . . . . . . . . . . . . . . . .144

8.2 Information technology systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .147

8.2.1 Measuring and control systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .154

8.2.2 Building control systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .154

8.2.3 Generic cabling systems (EDP networks, TC installations) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .155

8.2.4 Intrinsically safe circuits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .156

8.2.5 Special features of the installation of SPDs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .159

9. Application proposals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .163

9.1 Surge protection for frequency converters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .163

9.2 Lightning and surge protection of MW wind turbines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .165

9.3 Lightning and surge protection for PV systems and solar power plants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .169

9.3.1 Lightning and surge protection for PV systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .169

9.3.2 Lightning and surge protection for solar power plants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .174

9.4 Retrofitting lightning and surge protection for sewage plants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .177

9.5 External and internal lightning protection for churches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .181

9.6 Application proposal for lightning and surge protection in modern agriculture . . . . . . . . . . . . . . . . . . . . . . . . . . .185

9.7 Surge protection for video surveillance systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .189

9.8 Surge protection for electromechanical truck scales with microcomputer-controlled electronic evaluation unit .193

9.9 Lightning and surge protection for automatic fire alarm systems and burglar alarm systems . . . . . . . . . . . . . . . .195

9.10 Lightning and surge protection of an EIB system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .199

9.11 Surge protection for ETHERNET and Fast Ethernet networks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .201

9.12 Surge protection for M-Bus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .203

9.13 Surge protection for Sauter Cumulus systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .207

9.14 Lightning and surge protection for Honeywell building management systems . . . . . . . . . . . . . . . . . . . . . . . . . . . .213

9.15 Surge protection for PROFIBUS FMS, PROFIBUS DP, and PROFIBUS PA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .219

9.16 Surge protection for telecommunication accesses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .223

9.17 Lightning and surge protection for intrinsically safe circuits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .227

References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .231

Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .233

Figures and Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .235


General Key to Symbols used in Diagrams


Trademarks

"BLITZDUCTOR"

BLITZPLANER

"DEHNALU-DRAHT

"DEHNbloc"

"DEHNfix"

"DEHNgrip"

"DEHNguard"

"DEHNport"

"DEHNQUICK

"DEHNsnap"

"DEHNventil"

HVI

...MIT SICHERHEIT DEHN.

and our logo

are registered trademarks ofDEHN + SHNE GmbH + Co.KG.

Symbol* Description

PEN conductor

N conductor

PE conductor

Movable conductor,e.g. expansion piece

Expansion loop(at concrete joints)

Adjustableresistor

Thermistor, adjustable

Socket(of a socket outletor a plug-in connection)

Suppressordiodebipolar

Earth (general)

Lamp

Symbol* Description

Semiconductor

Fuse (general)

Gas discharge tube(basic)

Resistor,Decoupling element(general)

Transformer

Zener diode, unipolar

Capacitor

Inductor

Interface

ClampExternal lightning protection

Local equipotentialbondingSurge arrester

Symbol* Description

Lightning equipotentialbondingLightning current arrester

Lightning equipotentialbondingLightning current arrester

Local equipotentialbondingSurge arrester

Local equipotentialbondingSurge arrester(SPD Type 1)

Local equipotentialbondingSurge arrester(SPD Type 2, SPD Type 3)

Isolating spark gap

Isolating spark gap

Combined surge protectivedevice for power supplyand IT systems

Surge arresterfor hazardous areas

Varistor

Equipotentialbonding bar

*) according to DIN V VDE V 0185-3 (VDE V 0185 Part 3): 2002-11 and DIN EN 60617: 1997-08

1. State of the Art for the installation of lightning protection systems1.1 Installation standardsWith effect from 1 November 2002,Parts 1 to 4 of a new series of pre-standards - VDE V 0185 - for the instal-lation of lightning protection systemswas published. At the same time, allobsolete standards, prestandards andthe previously published drafts of theVDE 0185 lightning protection serieswere withdrawn (Table 1.1.1). The newseries of prestandards will be valid in itspresent form until at least the middleof 2006. By then, the work on theIEC 62305 series of international stan-dards, whose contents will correspondto the prestandards, will have beencompleted (Table 1.1.2). These meas-ures were necessary to put the State ofthe Art for lightning protection backon a uniform and up-to-date basis. Theactual protection prestandards (Part 3and Part 4) are preceded by two gener-ally valid prestandards (Part 1 andPart 2).

DIN V VDE V 0185-1: General principles

This section contains informationabout the risk posed by lightning, light-ning characteristics, and the parame-ters derived therefrom for the simula-tion of the effects of lightning. In addi-tion, an overall view of theDIN V VDE V 0185 series of standards isgiven. Procedures and protection prin-ciples which form the basis of the fol-lowing sections are explained.

DIN V VDE V 0185-2:Risk management

Risk management in accordance withDIN V VDE V 0185-2 uses risk analysis tofirst establish the necessity for light-ning protection. The optimum protec-tive measure from a technical and eco-nomic point of view is then deter-mined. Finally, the remaining residualrisk is ascertained. Starting with theunprotected state of the building, the

remaining risk is reduced and reduceduntil it is below the acceptable risk. Thismethod can be used both for a simpledetermination of the type of a light-ning protection system in accordancewith DIN V VDE V 0185-3, and also toestablish a complex protection systemagainst lightning electromagneticimpulse (LEMP) in accordance withDIN V VDE V 0185-4.

DIN V VDE V 0185-3: Physical damage to structures and lifehazard

This section deals with the protectionof buildings and structures and personsfrom material damage and life-threat-ening situations caused by the effect oflightning current or by dangeroussparking, especially in the event ofdirect lightning strokes. A lightningprotection system comprising externallightning protection (air-terminationsystem, down-conductor system andearth-termination system) and internal

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Classification Title

DIN 57185-1 Lightning protection system; (VDE 0185 Part 1): 1982-11 General with regard to installation

DIN 57185-2 Lightning protection system;(VDE 0185 Part 2): 1982-11 Erection of especially structures

DIN IEC 81/122/CD Protection of structures against lightning(VDE 0185 Part 10): 1999-02 Part 1: General principles

DIN V ENV 61024-1 Protection of structures against lightning(VDE V 0185 Part 100): 1996-08 Part 1: General principles

DIN IEC 61662 Assessment of the risk of damage due to lightning(VDE 0185 Part 101): 1998-11

DIN IEC 61024-1-2 Protection of structures against lightning -(VDE 0185 Part 102): 1999-02 Part 1-2: General principles

Guide B: Design, installation, maintenance and inspection of lightning protection systems

DIN VDE 0185-103 Protection against lightning electromagnetic impulse (LEMP) (VDE 0185 Part 103): 1997-09 Part 1: General principles

DIN IEC 81/105A/CDV Protection against lightning electromagnetic impulse (LEMP) (VDE 0185 Part 104): 1998-09 Part 2: Shielding of structures, bonding inside structures and earthing

DIN IEC 81/106/CDV Protection against lightning electromagnetic impulse (LEMP) - (VDE 0185 Part 105): 1998-04 Part 4: Protection for existing structures

DIN IEC 81/120/CDV Protection against lightning electromagnetic impulse (LEMP) (VDE 0185 Part 106): 1999-04 Part 3: Requirements of surge protective devices (SPDs)

DIN IEC 81/121/CD Protection against lightning electromagnetic impulse (LEMP) (VDE 0185 Part 106/A1): 1999-04 Part 3: Requirements of surge protective devices (SPDs);

Amendment 1: Coordination of SPDs within existing structures

DIN IEC 81/114/CD Test parameters simulating the effects of lightning protection system (L.P.S.)(VDE 0185 Part 107): 1999-01 components

DIN V VDE V 0185-110 Lightning protection system (VDE 0185 Part 110): 1997-01 Guide for testing lightning protection systems

Table 1.1.1 Lightning protection standards withdrawn as from 1 November 2002

lightning protection (lightning equipo-tential bonding and separation dis-tance) serves as a protective measure.The lightning protection system isdefined by its type, Type I being moreeffective than Type IV. The typerequired is determined with the help ofa risk analysis carried out in accordancewith DIN V VDE V 0185-2, unless other-wise laid down in regulations (e. g.building regulations).

DIN V VDE V 0185-4: Electrical and electronic systems withinstructures

This section deals with the protectionof buildings and structures with electri-cal and electronic systems against theeffects of the lightning electromagne-tic impulse. Based on the protectivemeasures according toDIN V VDE V 0185-3, this prestandardalso takes into consideration the effectsof electrical and magnetic fields, andinduced voltages and currents, causedby direct and indirect lightning strokes.The importance and necessity of theprestandard derives from the increa-sing use of diverse electrical and elec-tronic systems which are groupedtogether under the heading informa-tion systems. For the protection ofinformation systems, the building orstructure is divided up into lightningprotection zones (LPZ). This allows localdifferences in the number, type andsensitivity of the electrical and elec-tronic devices to be taken into consid-eration when choosing the protectivemeasures. For each lightning protec-tion zone, a risk analysis in accordancewith DIN V VDE V 0185-2 is used toselect those protective measures whichprovide optimum protection at mini-mum cost. The VDE prestandards VDE V 0185 Parts1 to 4 can be applied to the design,

installation, inspection and mainte-nance of lightning protection systemsfor buildings and structures, theirinstallations, their contents and thepersons within.

1.2 Work contractsA work contractor is fundamentallyliable for ensuring that his service isfree from defects. The decisive startingpoint for a defect-free service is compli-ance with the recognised engineeringrules. Relevant VDE and DIN standardsare used here in order to fill the factualcharacteristic of the recognised engi-neering rules with life. If the relevantstandards are complied with, it is pre-sumed that the service is free fromdefect. The practical significance ofsuch a prima facie evidence lies in thefact that a customer who lodges a com-plaint of defective service by the workcontractor (for example for the installa-tion of a lightning protection system)has basically little chance of success ifthe work contractor can show that hecomplied with the relevant technicalstandards. As far as this effect is con-cerned, standards and prestandardscarry equal weight. The effect of thepresumption of technical standards isremoved, however, if either the stan-dards are withdrawn, or it is proventhat the actual standards no longerrepresent the State of the Art. VDE orDIN standards cannot statically laydown the state of the recognised engi-neering rules in tablets of stone, astechnical requirements and possibilitiesare continually changing. If standardsare withdrawn, therefore, andreplaced with new standards or pre-standards, then it is primarily the newstandards which then correspond tothe State of the Art.

Contractors and those placing an orderfor work regularly agree that the workmust conform to the general State ofthe Art without the need to make spe-cific mention of this. If the work showsa negative deviation from this generalState of the Art, it is defective. This canresult in a claim being made againstthe contractor for material defect lia-bility. The material defect liability onlyexists, however, if the work was alreadydefective at the time of acceptance!Circumstances which occurring subse-quently - such as a further develop-ment of the State of the Art do notbelatedly make the previously accept-ed, defect-free work defective!For the question of the defectiveness ofa works management, the state of therecognised engineering rules at thetime of the acceptance is the soledeciding factor.Since, in future, only the new lightningprotection prestandards will be rele-vant at the time of completion andacceptance of lightning protection sys-tems, have to be installed in accor-dance with these prestandards. It is notsufficient that the service conformed tothe engineering rules at the time it wasprovided, if, between completion of acontract, service provision and accept-ance of the construction work, thetechnical knowledge and hence theengineering rules have changed.Hence works which have been previ-ously installed and already acceptedunder the old standards do not becomedefective because, as a result of theupdating of the standards, a highertechnical standard is demanded.With the exception of lightning protec-tion systems for nuclear facilities, light-ning protection systems have only toconform to the State of the Art at thetime they are installed, i. e. they do nothave to be updated to the latest Stateof the Art. Existing systems are inspected in the course of maintenancetests according to the standards inforce at the time they were installed.

www.dehn.de

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8 LIGHTNING PROTECTION GUIDE

Classification Title

DIN V VDE V 0185-1 Protection against lightning(VDE V 0185 Part 1): 2002-11 Part 1: General principles

DIN V VDE V 0185-2 Protection against lightning(VDE V 0185 Part 2): 2002-11 Part 2: Risk management

Assessment of risk for structures

DIN V VDE V 0185-3 Protection against lightning(VDE V 0185 Part 3): 2002-11 Part 3: Physical damage to structures

and life hazard

DIN V ENV 61024-1 Protection against lightning(VDE V 0185 Part 4): 2002-11 Part 4: Electrical and electronic systems

within structures

Table 1.1.2 Draft lightning protection standards valid since 1 November 2002

1.3 Product standardsMaterials, components and units forlightning protection systems must bedesigned and tested for the electrical,mechanical and chemical stresses whichhave to be expected during their use.This affects both the components ofthe external lightning protection aswell as units of the internal lightningprotection system.

DIN EN 50164-1 (VDE 0185 Part 201): Requirements for connection compo-nents

This standard describes inspection andtest procedures for metal connectingunits. Units falling within the scope ofthis standard are:

Clamps Connectors Terminal components Bridging components Expansion pieces Measuring pointsOur clamps and connectors meet therequirements of this test standard.

DIN EN 50164-2 (VDE 0185 Part 202):Requirements for conductors andearth electrodes

This standard specifies the require-ments on conductors, air-terminationrods, lead-in components and earthingelectrodes. This standard supersedesthe corresponding standards of the DIN488XX series.

DIN EN 61643-11 (VDE 0675 Part 6-11):Surge protective devices connected tolow voltage systems

Previously, the development, manufac-ture, and testing of surge protectivedevices for use in low voltage systemswas based on E DIN VDE 0675 Part 6, EDIN VDE 0675 Part 6/A1 and E DIN VDE0675 Part 6/A2. These standards couldbe used as the basis of conformity testsfor surge protective devices until 1 October 2004. Surge protectivedevices which correspond to this seriesof standards are subdivided into ClassA, B, C and D arresters.Since 1 December 2002, the require-ments on, and inspections of, surgeprotective devices in low voltage sys-tems have been governed by DIN EN61643-11 (VDE 0675 Part 6-11). Thisproduct standard is the result of inter-national standardisation as part of IECand CENELEC. While, in many cases, theinspection and test proceduresdescribed therein meet the require-ments and inspections of the previous,authorised draft standards E DIN VDE0675 Part 6, E DIN VDE 0675 Part 6/A1and E DIN VDE 0675 Part 6/A2, the DINEN 61643-11 (VDE 0675 Part 6-11) nev-ertheless brings some changes for theuser as well. In the future, the classifi-cation characteristic for surge protec-tive devices (SPDs) will be Test Classes .We will now differentiate betweensurge protective devices as SPD Type 1,SPD Type 2 and SPD Type 3. The corre-lations between old and new classifica-tions according to the product stan-dards for surge protective devices areshown in Table 1.3.1.

DIN EN 61643-21 (VDE 0845 Part 3-1):Surge protective devices connected totelecommunications and signallingnetworks

This standard describes the perform-ance requirements, and inspection andtest procedures for surge protectivedevices used for the protection oftelecommunication and signal process-ing networks including e. g.

data networks, voice transmission networks, alarm systems, automation systems.

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So far In the future(transition period until 1 October 2004) (in force since 1 December 2002)

E DIN VDE 0675-6 DIN EN 61643-11E DIN VDE 0675-6/A1 (VDE 0675 Part 6-11)E DIN VDE 0675-6/A2

Class B SPD Type 1

Class C SPD Type 2

Class D SPD Type 3

Table 1.3.1 Classification of surge protective devices (SPDs)

www.dehn.de

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2.1 Lightning discharge andtemporal developmentof the lightning current

Every year, an average of around onemillion lightning strokes discharge overGermany. For an area of 357,042 km2

this corresponds to an average flashdensity of 2.8 lightning discharges persquare kilometre per year. The actuallightning density, however, depends toa large extent on geographic condi-tions. An initial overview can beobtained from the lightning densitymap contained in DIN V VDE V 0185-2.The higher the resolution of the light-ning density map, the more accuratethe information it provides about theactual lightning frequency in the areaunder consideration.Using the BLIDS lightning location sys-tem, it is now possible to locate light-ning to within 200 m in Germany. Forthis purpose, twelve measuring out-posts are spread throughout the coun-try. They are synchronised by means ofthe highly accurate time signal of theglobal positioning system (GPS). Themeasuring posts record the time theelectromagnetic wave produced by thelightning discharge arrives at thereceiver. From the differences in thetimes of arrival of the electromagneticwave recorded by the various receivers,and the corresponding differences inthe times it takes the electromagneticwave to travel from the location of thelightning discharge to the receivers,the point of strike is calculated. Thedata determined in this way are filedcentrally and made available to theuser in form of various packages. Fur-ther information about this service canbe obtained from www.blids.de. Thunderstorms come into existencewhen warm air masses containing suffi-cient moisture are transported to greataltitudes. This transport can occur in anumber of ways. In the case of heatthunderstorms, the ground is heatedup locally by intense insolation. Thelayers of air near the ground heat upand rise. For frontal thunderstorms, theinvasion of a cold air front causes cooler air to be pushed below thewarm air, forcing it to rise. Orographicthunderstorms are caused when warmair near the ground is lifted up as itcrosses rising ground. Additional physi-cal effects further increase the verticalupsurge of the air masses. This formsupdraught channels with vertical speedsof up to 100 km/h, which create tower-ing cumulonimbus clouds with typical

heights of 5 12 km and diameters of5 10 km. Electrostatic charge separation process-es, e. g. friction and sputtering, areresponsible for charging water dropletsand particles of ice in the cloud.Positively charged particles accumulatein the upper part, and negativelycharged particles in the lower part ofthe thundercloud. In addition, there isagain a small positive charge centre atthe bottom of the cloud. This origi-nates from the corona discharge whichemanates from sharp-pointed objectson the ground underneath the thun-dercloud (e. g. plants), and is trans-ported upwards by the wind.If the space charge densities, whichhappen to be present in a thunder-cloud, produce local field strengths ofseveral 100 kV/m, leader discharges(leaders) are formed which initiate alightning discharge. Cloud-to-cloudflashes result in charge neutralisationbetween positive and negative cloudcharge centres, and do not directlystrike objects on the ground in theprocess. The lightning electromagneticimpulses (LEMP) they radiate must betaken into consideration, however,because they endanger electrical andelectronic systems.

Lightning flashes to earth lead to aneutralisation of charge between thecloud charges and the electrostatic

charges on the ground. We distinguishbetween two types of lightning flashesto earth:

Downward flash Upward flash

2. Characteristics of lightning current

Fig. 2.1.1 Downward flash (cloud-to-earth flash)

leader

cloud-to-earth flash(negative downward flash)

Fig. 2.1.2 Discharge mechanism of a negative down-ward flash (cloud-to-earth flash)

leader

cloud-to-earth flash(positive downward flash)

Fig. 2.1.3 Discharge mechanism of a positive down-ward flash (cloud-to-earth flash)


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In the case of downward flashes, leaderdischarges pointing towards theground guide the lightning dischargefrom the cloud to the earth. Such dis-charges usually occur in flat terrain andnear low buildings and structures.Downward flashes can be recognisedby the branching (Fig. 2.1.1) which isdirected earthwards. The most com-mon type of lightning is negative light-ning flashes to earth, where a leaderfilled with negative cloud charge pushes its way from the thunder cloud

to earth (Fig. 2.1.2). This leader propa-gates in a series of jerks with a speed ofaround 300 km/h in steps of a few 10 m.The interval between the jerksamounts to a few 10 s. When theleader has drawn close to the earth, (afew 100 m to a few 10 m), it causes thestrength of the electric field of objectson the surface of the earth in the vicin-ity of the leader (e. g. trees, gable endsof buildings) to increase. The increase isgreat enough to exceed the dielectricstrength of the air. These objects

involved reach out to the leader bygrowing positive streamers which thenmeet up with the leader, initiating themain discharge.Positive flashes to earth can arise out ofthe lower, positively charged area of athundercloud (Fig. 2.1.3). The ratio ofthe polarities is around 90 % negativelightning to 10 % positive lightning.This ratio depends on the geographiclocation. On very high, exposed objects (e. g.radio masts, telecommunication towers, steeples) or on the tops ofmountains, upward flashes (earth-to-cloud flashes) can occur. It can berecognised by the upwards-reachingbranches of the lightning discharge(Fig. 2.1.4). In the case of upward flashes, the high electric field strengthrequired to trigger a leader is notachieved in the cloud, but rather by thedistortion of the electric field on theexposed object, and the associatedhigh strength of the electric field. Fromthis location, the leader and its chargechannel propagate towards the cloud.Upward flashes occur with both nega-tive polarity (Fig. 2.1.5) and also withpositive polarity (Fig. 2.1.6). Since, withupward flashes, the leaders propagatefrom the exposed object on the surfaceof the earth to the cloud, high objectscan be struck several times by one light-ning discharge during a thunderstorm. Objects struck by lightning are subjectto higher stress by downward flashes(cloud-to-earth flashes) than byupward flashes (earth-to-cloud flash-es). The parameters of downwardflashes are therefore taken as the basiswhen designing lightning protectionmeasures.Depending on the type of lightningflash, each lightning discharge consistsof one or more partial strokes of light-ning. We distinguish between shortstrokes with less than 2 ms durationand long strokes with a duration ofmore than 2 ms. Further distinctive fea-tures of partial lightning strokes aretheir polarity (negative or positive),and their temporal position in thelightning discharge (first, subsequentor superimposed partial strokes oflightning). The possible combinationsof partial lightning strokes are shownin Fig. 2.1.7 for downward flashes, andFig. 2.1.8 for upward flashes.The lightning currents consisting ofboth impulse currents and continuingcurrents are load-independent cur-rents, i. e. the objects struck exert noeffect on the lightning currents. Fourparameters important for lightning

Fig. 2.1.4 Upward flash (earth-to-cloud flash)

leader

earth-to-cloud flash(negative upward flash)

leader

earth-to-cloud flash(positive upward flash)

Fig. 2.1.5 Discharge mechanism of a negativeupward flash (earth-to-cloud flash)

Fig. 2.1.6 Discharge mechanism of a positive upwardflash (earth-to-cloud flash)

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protection technology can be obtainedfrom the lightning current profilesshown in Figs. 2.1.7 and 2.1.8:

The peak value of lightning current I The charge of the lightning current

Qflash, comprising the charge of theshort stroke Qshort and the chargeof the long stroke Qlong

The specific energy W/R of thelightning current

The steepness di/dt of the lightningcurrent.

The following chapters show which ofthe individual efficiency parameters areresponsible for which effects, and howthey influence the dimensioning oflightning protection systems.

2.2 Peak value of the light-ning current

Lightning currents are load-independ-ent currents, i.e. a lightning dischargecan be considered an almost ideal cur-rent source. If a load-independentactive electric current flows throughconductive components, the amplitudeof the current, and the impedance ofthe conductive component the currentflows through, help to regulate thepotential drop across the componentflown through by the current. In thesimplest case, this relationship can bedescribed using Ohms Law.

If a current is formed at a single pointon a homogeneously conducting sur-face, the well-known potential gradi-ent area arises. This effect also occurswhen lightning strikes homogeneousground (Fig. 2.2.1). If living beings(people or animals) are inside thispotential gradient area, a step voltageis formed which can cause a shock cur-rent to flow through the body(Fig. 2.2.2). The higher the conductivityof the ground, the flatter the shape ofthe potential gradient area. The risk ofdangerous step voltages is thus alsoreduced.

U I R= i

I

first impulse current

positive or negative t

I

long-time current

positive or negative t

I

sequential impulse currents

negative t

I

negative t

Fig. 2.1.7 Possible components of downward flashes

I

short stroke

Positive or negative t

I

long stroke


Isubsequentshort strokes

Negative t

I

Negative t

first long stroke

superimposedshort strokes

I


single long

stroke

Fig. 2.1.8 Possible components of upward flashes

Fig. 2.2.1 Potential distribution of a lightning strokeinto homogenous soil

Fig. 2.2.2 Animals killed by shock current due tohazardous step voltage


2222

If lightning strikes a building which isalready equipped with a lightning pro-tection system, the lightning currentflowing away via the earth-terminationsystem of the building gives rise to apotential drop across the earthingresistance RE of the earth-terminationsystem of the building (Fig. 2.2.3). Aslong as all conductive objects in thebuilding, which persons can come intocontact with, are raised to the samehigh potential, persons in the buildingcannot be exposed to danger. This iswhy it is necessary for all conductiveparts in the building with which per-sons can come into contact, and allexternal conductive parts entering thebuilding, to have equipotential bond-ing. If this is disregarded, there is a riskof dangerous shock hazard voltages iflightning strikes.The rise in potential of the earth-termi-nation system as a result of the light-ning current also creates a hazard forelectrical installations (Fig. 2.2.4). In theexample shown, the operational earthof the low voltage supply network islocated outside the potential gradientarea caused by the lightning current. Iflightning strikes the building, thepotential of the operational earth RB istherefore not identical to the earthpotential of the consumer system with-in the building. In the present example,there is a difference of 1000 kV. Thisendangers the insulation of the electri-cal system and the equipment connect-ed to it.

lightning current

Time

air-terminationsystem

down-conductorsystem

earth-termination systemwith earth resistance RE

remote earth

Curr

ent

Fig. 2.2.3 Potential rise of the earth-termination system of a building compared to the remote earth due tothe peak value of the lightning current

!

"

Fig. 2.2.4 Threat to electrical installations by potential rise at the earth-termination system

2.3 Steepness of lightningcurrent

The steepness of lightning currenti/t, which is effective during theinterval t, determines the height ofthe electromagnetically induced volt-ages. These voltages are induced in allopen or closed conductor loops locatedin the vicinity of conductors throughwhich lightning current is flowing.Fig. 2.3.1 shows possible configurationsof conductor loops in which lightningcurrents could induce voltages. Thesquare wave voltage U induced in aconductor loop during the interval tis:

M Mutual inductance of the loop

i/t Steepness of lightning currentAs already described, lightning dis-charges comprise a number of partialstrokes lightning. As far as the tempo-ral position is concerned, a distinction ismade between first and subsequentshort strokes within a lightning dis-charge. The main difference betweenthe two types of short strokes consistsin the fact that, because the lightningchannel has to be built, the gradient ofthe lightning current of the first shortstroke is not as steep as that of the sub-sequent short stroke, which can use anexisting, fully conductive lightningchannel. The steepness of lightningcurrent of the subsequent lightningstroke is therefore used to assess thehighest induced voltage in the conduc-tor loops.An example of how to assess theinduced voltage in a conductor loop isshown in Fig. 2.3.2.

2.4 Charge of lightning current

The charge Qflash of the lightning cur-rent is made up of the charge Qshort ofthe short stroke and the charge Qlong ofthe long stroke. The charge

of the lightning current determines theenergy deposited at the precise pointof strike, and at all points where thelightning current continues in theshape of an electric arc along an insu-lated path. The energy W deposited at

Q idt=

U Mi

t= i

2222


10

1

0.1

0.01

0.001

0.1 10-3

0.01 10-30.1 0.3 1 3 10 30

H

M2

i t

a

a

U

s

10 m

10 m

U

1 m

installation loopof an alarm system high requirement

= 150 i t

kAs

From the figure besidefollows:

M2 4.8 H U = 4.8 150 = 720 kV

s m

a = 10 m

a = 3 m

a = 1 m

a = 0.1 m

a = 0.3 ma = 0.03 ma = 0.01 m

Fig. 2.3.1 Induced square-wave voltage in loops via the current steepness i/t of the lightning current

Fig. 2.3.2 Example for calculation of induced square-wave voltages in squared loops

s 3

s2

s 1

/ T1

1

2

3

building

downconductor

100% lightning current90%

10%Time

front time T1

U

T1

induced square-wave voltage

Time

Curr

ent

Volta

ge

1 Loop in the down conductor with potential flashoverdistance s1

2 Loop out of down conductor and installation cablewith potential flashover distance s2

3 Installation loop with potential flashover distance s3

the base of the electric arc is given bythe product of the charge Q and theanode-/cathode drop with values in themicrometer range UA,K (Fig. 2.4.1). Theaverage value of UA,K is a few 10 V anddepends on influences such as theheight and shape of the current:

Q Charge of lightning current

UA,K Anode/cathode drop

Hence, the charge of the lightning cur-rent causes the components of thelightning protection system struck bylightning to melt down. The charge isalso relevant for the stresses on isolat-ing spark gaps and protective sparkgaps and by spark-gap based surge pro-tective devices.Recent examinations have shown that,as the electric arc acts for a longer time,it is mainly the continuing charge Qlongof the continuing current which is ableto melt or vaporise large volumes ofmaterial. Figs. 2.4.2 and 2.4.3 show acomparison of the effects of the shortstroke charge Qshort and the long strokecharge Qlong

W Q UA K= i ,

100 kA (10/350 s) galvanised steel 100 kA (10/350 s) copper


2222

Time

lightning current

long stroke current

Time

Curr

ent

Curr

ent

smelt metal

Q

UA,K

tip of thedown conductor

Fig. 2.4.1 Energy conversion at the point of strike bythe load of the lightning current

Fig. 2.4.2 Effect of an impulse current arc on a metal surface

Fig. 2.4.3 Plates perforated by the effects of long-time arcs

Copper: d = 0.5 mm; 200 A, 180 msAluminium: d = 0.5 mm; 200 A, 350 ms

Steel: d = 0.5 mm; 200 A, 100 msStainless steel: d = 0.5 mm; 200 A, 90 ms

Galvanised steel: d = 0.5 mm; 200 A, 100 ms

2.5 Specific energyThe specific energy W/R of an impulsecurrent is the energy deposited by theimpulse current in a resistance of 1.This energy deposition is the integral ofthe square of the impulse current overthe time for the duration of theimpulse current:

The specific energy is therefore oftencalled the current squared impulse. It isrelevant for the temperature rise inconductors through which a lightningimpulse current is flowing, as well asfor the force exerted between conduc-tors flown through by a lightningimpulse current (Fig. 2.5.1).

For the energy W deposited in a con-ductor with resistance R we have:

R (Temperature dependent) dcresistance of the conductor

W/R Specific energy

The calculation of the temperature riseof conductors through which a light-ning impulse current is flowing, canbecome necessary if the risks to per-sons, and the risks from fire and explo-sion, have to be taken into accountduring the design and installation oflightning protection systems. The calcu-lation assumes that all the thermalenergy is generated by the ohmicresistance of the components of thelightning protection system. Further-more, it is assumed that, because of thebrevity of the process, there is no per-ceptible heat exchange with the sur-roundings. Table 2.5.1 lists the temper-ature rises of different materials usedin lightning protection, and their cross-sections, as a function of the specificenergy.

The electrodynamic forces F generatedby a current i in a wire with a long, par-allel section of length l and a separa-tion d (Fig. 2.5.2) can be calculated asan approximation using the followingequation:

F(t) Electrodynamic force

i Current

0 Magnetic constant in air (4 10-7H/m)

l Length of conductor

d Separation between the parallelconductors

The force between the conductors isattractive if the two currents flow inthe same direction, and repulsive if thecurrents flow in opposite directions. Itis proportional to the product of thecurrents in the conductors, and inverse-ly proportional to the separation of theconductors. Even in the case of a single,bent conductor, a force is exerted onthe conductor. Here, the force is pro-portional to the square of the currentin the bent conductor.

F t

i tI

d( ) ( )= 0 2

2 i i

W R i dt RW

R= = i i2

W

Ri dt= 2 2222


W/R

powerimpulse

on parallelconductors

heating

lightningcurrent

Time

!

#

#

Fig. 2.5.1 Heating and force effects by the specificenergy of ligthning current

Fig. 2.5.2 Electrodynamic effect between parallel conductors

Material

Cross Aluminium Iron Copper Stainless steelsection W/R [MJ/] W/R [MJ/] W/R [MJ/] W/R [MJ/][mm2] 2.5 5.6 10 2.5 5.6 10 2.5 5.6 10 2.5 5.6 10

4 10 564 169 542 16 146 454 1120 56 143 309 25 52 132 283 211 913 22 51 98 940 50 12 28 52 37 96 211 5 12 22 190 460 940

100 3 7 12 9 20 37 1 3 5 45 100 190

Table 2.5.1 Temperature rise T in K of different conductor materials

The specific energy of the impulse cur-rent thus determines the load whichcauses a reversible or irreversible defor-mation of components and arrays of alightning protection system. Theseeffects are taken into consideration inthe test arrangements of the productstandards concerning the requirementsmade on connecting components forlightning protection systems.

2.6 Assignment of lightningcurrent parameters tolightning protection levels

In order to define lightning as a sourceof interference, lightning protectionlevels I to IV are laid down. Each light-ning protection level requires a set of

maximum values (dimensioning cri-teria used to design lightning pro-tection components to meet thedemands expected to be made ofthem) and

minimum values (interception cri-teria necessary to be able to deter-mine the areas with sufficient pro-tection against direct lightningstrokes (radius of rolling sphere)).

Table 2.6.1 shows the assignment of thelightning protection levels to maximumand minimum values of the lightningcurrent parameters.


2222

Maximum values Minimum values(Dimensioning criteria) (Interception criteria)

Lightning Max. Probability Min. Probability Radiusprotection lightning of the actually lightning of the actually of the

level current upcoming current upcoming rolling spherepeak value lightning peak value lightning

current currentto be less to be higher

than the max. than the min.lightning lightningcurrent current

peak value peak value

I 200 kA 99 % 2.9 kA 99 % 20 m

II 150 kA 98 % 5.4 kA 97 % 30 m

III 100 kA 97 % 10.1 kA 91 % 45 m

IV 100 kA 97 % 15.7 kA 84 % 60 m

Table 2.6.1 Limit values of lightning current parametes and their probabilities

3. Designing a lightning protection system3.1 Requirement for a light-

ning protection system legal requirements

The purpose of a lightning protectionsystem is to protect buildings from directlightning strokes and possible fire, orfrom the consequences of the activelightning current (non-igniting flash oflightning).If national regulations, e. g. building reg-ulations, special regulations or specialdirectives require lightning protectionmeasures, they must be installed.

Unless these regulations contain specifi-cations for lightning protection meas-ures, a lightning protection system whichmeets the requirements of an LPS Type IIIaccording to DIN V VDE V 0185-3 (VDE V0185 Part 3) is recommended as mini-mum.Otherwise, the need for protection andthe choice of appropriate protectionmeasures, should be determined by riskmanagement.

The risk management is described in DINV VDE V 0185-2 (VDE V 0185 Part 2) [2](see Subclause 3.2.1).

Further information on how to deter-mine the type of lightning protection sys-tems for general buildings and structurescan be found in

the following directive of the VdS:VdS-Richtlinie 2010 Risikoorien-tierter Blitz- und berspan-nungsschutz, Richtlinien zurSchadenverhtung. [engl.: Risk-orientated lightning and surge pro-tection guideline for prevention ofdamage]

For example, the building regulations ofthe State of Hamburg (HbauO 17, Abs. 3) require a lightning protection sys-tem to be installed if lightning can easilystrike a building because of

its length, its height or the use to which it is put,or if

it is expected that a lightning strokewould have serious consequences.

This means:A lightning protection system must bebuilt even if only one of the require-ments is met.

A lightning stroke can have particularlyserious consequences for buildings andstructures owing to their location, type

of construction or the use to which theyare put.A nursery school, for example, is a build-ing where a lightning stroke can haveserious consequences because of the useto which the building is put.The interpretation to be put on thisstatement is made clear in the followingcourt judgement:

Extract from the Bavarian AdministrativeCourt, decision of 4 July 1984 No. 2 B 84A.624-.

1. A nursery school is subject to therequirement to install effective light-ning protection systems.

2. The legal requirements of the build-ing regulations for a minimum offire-retardant doors when designingstaircases and exits also apply to aresidential building which houses anursery school.

For the following reasons:According to the Bavarian building regu-lations (Art. 17 Abs. BayBO), buildingsand structures whose location, type ofconstruction or the use to which they areput, make them susceptible to lightningstrokes, or where such a stroke can haveserious consequences, must be equippedwith permanently effective lightningprotection systems. This stipulates therequirement for effective protectivedevices in two cases. In the first case, thebuildings and structures are particularlysusceptible to lightning strokes (e. g.because of their height or location); inthe other case, any lightning stroke (e. g.because of the type of construction orthe use to which it is put) can have par-ticularly serious consequences. The plain-tiffs building falls within the latter cate-gory because of its present use as a nurs-ery school. A nursery school belongs tothe group of buildings where a lightningstroke can have serious consequencesbecause of the use to which the buildingis put. It is of no consequence that, in theannotations to the Bavarian buildingregulations, nursery schools are notexpressly mentioned in the illustrative listof buildings and structures which areparticularly at risk, alongside meetingplaces (cf. Simon, Komm. zur BayBO,Rdnr. 26 zu Art. 17,Koch/ Molodovsky,Komm. zur BayBO, Erl. 7.1 zu Art. 17).The risk of serious consequences if light-ning strikes a nursery school arisesbecause, during the day, a large numberof children under school age are presentat the same time.

The fact that the rooms where the chil-dren spend their time are on the ground

floor, and that the children could escapeto the outside through several windows as put forward by the plaintiff is not adeciding factor. In the event of fire, thereis no guarantee that children of this agewill react sensibly and leave the buildingvia the windows if necessary. In addition,the installation of sufficient lightningprotection equipment is not too much toexpect of the operator of a nurseryschool. A further section of the Bavarianbuilding regulations (Art. 34 Abs. 8 Bay-BO) requires that, amongst other things,staircases must have entrances to the cel-lar which have self-closing doors whichare, at least, fire-retardant. The require-ments do not apply to residential build-ings with up to two flats (Art. 34 Abs. 10BayBO). The respondent only made thedemand when the plaintiff convertedthe building, which was previously resi-dential, into a nursery school as well, inaccordance with the authorised changeof use. The exemption provision (Art. 34Abs. 10 BayBO) cannot be applied tobuildings which were built as residentialbuildings with up to two flats, but whichnow (also) serve an additional purposewhich justifies the application of thesafety requirements (Art. 34 Abs. 1 bis 9BayBO). This is the case here.

VGH, B.4.7.84, 597 = BRS 42, 290)[From annotations to Bavarian buildingregulations as at 1 August 1994 to Art. 16Fire protection]

Serious consequences (panic) can alsoarise when lightning strikes assemblyrooms, schools, hospitals.For these reasons, it is necessary that allbuildings and structures which are at riskof such events are equipped with perma-nently effective lightning protection sys-tems.[Lower Saxony Building Regulations,annotations to F. Lightning protectionsystems. (Abs. 3)]

Lightning protection systems alwaysrequiredAccording to the regulation concerningthe monitoring of technical installationsin buildings, buildings and structureswhere a lightning protection systemmust always be included because, inthese cases, the law has affirmed theneed, are

1. Assembly places with stages or cov-ered stage areas and assembly placesfor the showing of films, if theaccompanying assembly rooms ineach case, either individually ortogether, can accommodate morethan 100 visitors.

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www.dehn.de

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2. Assembly places with assemblyrooms which individually or togethercan accommodate more than 200 vis-itors; in the case of schools, museumsand similar buildings, this regulationonly applies to the inspection oftechnical installations in assemblyrooms which individually can accom-modate more than 200 visitors, andtheir escape routes;

3. Sales areas whose sales rooms havemore than 2000 m2 of floor space;

4. Shopping centres with several salesareas which are connected to eachother either directly or via escaperoutes, and whose sales rooms indi-vidually have less than 2000 m2 offloor space but having a total floorspace of more than 2000 m2;

5. Exhibition spaces whose exhibitionrooms individually or together havemore than 2000 m2 of floor space;

6. Restaurants with seating for morethan 400 customers, or hotels withmore than 60 beds for guests;

7. High-rise buildings as defined in theHamburg building regulations (2Abs. 2 HbauO);

8. Hospitals and other buildings andstructures having a similar purpose;

9. Medium-sized and large-scalegarages as defined in the Hamburgregulations for garages (1 Abs. 5Garagenverordnung vom 17. April1990 Hamburgisches Gesetz- undVerordnungsblatt, Seite 75);

10. Buildings and structures

10.1 with explosive materials, such asammunition factories, depots forammunition and explosives,

10.2 with factory premises which are atrisk of explosion, such as varnishand paint factories, chemical facto-ries, larger depots of combustibleliquids and larger gas holders,

10.3 particularly at risk of fire, such as larger woodworking factories,

buildings with thatched roofs,and

warehouses and productionplants with a high fire load,

10.4 for larger numbers of people suchas schools,

homes for the elderly and chil-drens homes,

barracks,

correctional facilities

and railway stations,

10.5 with cultural assests, such as Table 3.1.1 Legal building regulations of the German Federal states on lightning protection (Part 1)

Federal Legal building regulations on lightning protectionstate

BuildingSpecial building regulations and guidelines

Testregulations Multistorey Hospital School Assembly Sales regulation

building facility facility TR2)

All federal Issue (12/97) (12/87) (12/76) (06/90) draft (09/95)states (9/01)

(Model Source 17 Par. 5 Pkt. 4.9.5 26 3.20 14 Par. 4 19regulations)

Test 5.4.3/ 38/ 5.4/ TR3 years 5 years 5 years

Baden- Issue (12/97) (09/90) (02/82) (02/97)Wurttem-

Source 15 Par. 2 5.2 19berg

Test 127/BW 1 Jahr

Bavaria Issue (08/97) (11/97) (01/02)

Bay Source Art. 15.(7) 19 2 (4)

Test

Berlin Issue (06/98) (01/98)

Bln Source 19

Test 124/1 year

Branden- Issue (03/98) (10/90) (10/90) (10/90) (07/98)burg

Source 17 Par. 5 13 Par. 6 26 6 19

Bra Test 3 years 38 A4/ 62/5 years 3 years

Bremen Issue (03/95) (08/79)

HB Source 17 Par. 7 Item 4.9.5

Test 5.4.3/3 years

Hamburg Issue (06/97)

Hbg Source 17 Par. 3

Test

Hesse Issue (02/98) (12/97) (08/91)

HE Source 17 Par. 5 Item 4.9.5

Test 5.4.3/ TR < 3 years3 years

Mecklen- Issue (05/98) (10/90) (10/90) (05/95) (10/90) (09/98)burg-West-

Source 14 Par. 5 13 Par. 6 26 3.20 6 19Pomerania

Test 3 years 38 A4/ 5.1.c/ 62/MV 5 years 5 years 3 years

Lower Issue (10/97) (07/78) (01/03) (01/97)Saxony

Source 20 Par. 3 3.20 19

Nds Test 5.1d/ 128/5 years 5 years

North Rine- Issue (03/00) (12/95) (12/95) (11/76) (12/95) (03/00) (12/95)Westphalia

Source 17 Par. 4 13 Par. 6 26 3.20 171)

NW Test TR TR TR TR TR 3 years

buildings of historic interest,

museums and archives,

10.6 towering above their surroundings,such as high chimneys,

towers and

high buildings.

[Kommentar zur HbauO, StandJuni 1999 zu 17 RNr. 23]

Table 3.1.1 contains the sources of therespective definitions in the state build-ing regulations of the German states.

The following list provides an overviewof the relevant "General Provisions" inGermany which deal with the issue ofrequirement, design and inspection oflightning protection systems.

General Provisions:

DIN 18384: 2000-12Contract procedure for building works(VOB)Part C: General technical specificationsfor building works (ATV);Lightning protection systems

Standard services book for the construc-tion industry (StLB)Service sector 050, lightning protectionand earth-termination systemsThe purpose of this standard servicesbook is to ensure conformity of the textsused in the service descriptions, and alsoto facilitate data processing. The texts are used for public tenders byall building authorities, and by federal,state and local governments.

DIN 48830: 1985-03Lightning protection system - DescriptionThis standard applies when drawing upthe description of a lightning protectionsystem which is required as part of thedesign documentation.

DIN V VDE V 0185-1(VDE V 0185 Part 3): 2002-11Part 1: General principlesIt contains all general principles for thelightning protection of buildings andstructures including their installations/content, persons and all utility lines

DIN V VDE V 0185-2(VDE V 0185 Part 2): 2002-11Part 2: Risk managementAssessment of risk for structures Applicable to the assessment of the riskof damage from cloud-to-earth flashesfor buildings

DIN V VDE V 0185-3(VDE V 0185 Part 3): 2002-11Part 3: Physical damage to structures andlife hazardThe basis for the design, installation,inspection and maintenance of lightningprotection systems for general buildingsand structures

DIN V VDE V 0185-4(VDE V 0185 Part 4): 2002-11Part 4: Electrical and electronic systemswithin structuresContains information about the design,installation, inspection, maintenance andtesting of systems which protect againstLEMP effects for buildings and structureswith electrical and particularly sensitiveelectronic systems (lightning protectionzones concept)

DIN 48801 ... 48852Components for external lightning pro-tectionThis series of standards specifies dimen-sions and material thicknesses.

3333


Federal Legal building regulations on lightning protectionstate

BuildingSpecial building regulations and guidelines

Testregulations Multistorey Hospital School Assembly Sales regulation

building facility facility TR2)

Rhineland- Issue (11/98) (01/89) (09/82) (07/98) (04/91)Palatinate

Source 15 Par. 5 10. 19

RP Test 11.3/ 124/ 5 years5 years 1year

Saarland Issue (07/98) (10/90) (10/90) (01/00) (01/79) (09/77)

Srl Source 18 Par. 4 13 Par. 6 26 6. 23

Test 3 years 38 A4/ 123/ 34/5 years 5 years 3 years

Saxony Issue (03/96) (10/90) (10/90) (11/99) (10/90) (10/92) (02/00)

Sa Source 17 Par. 5 13 Par. 6 26 Item 2.4 6 23 2 (2) 1.

Test 3 years 38 A4/ TR 62/ 34/ 5 years5 years 3 years 3 years

Saxony- Issue (02/01) (09/95) (09/95) (09/95) (09/95)Anhalt

Source 17 Par. 5 13.6 25 6. 19

LSA Test < 3 years 37.4/ 62/5 years 3 years

Schleswig- Issue (02/96) (09/84) (01/76) (07/84) (12/97)Holstein

Source 19 Par. 5 Item 4.9.5 3.20 19

SH Test 5.4.3/ 5.4/ 124/3 years 5 years 3 years

Thuringia Issue (06/94) (10/90) (10/90) (08/99) (10/90) (06/97) (04/93)

Th Source 17 Par. 5 13 Par. 6 26 6. 6 19

Test 3 years 38 A4/ 3 years 62/ TR 3 years5 years 3 years

Update 07/021) Commercial building regulations2) Individual Federal states provide test intervals in special test regulations (TR)TR in He = Building test regulations for sales facilities onlyTR in HH, RP, Sa, Th = State regulations on the test of Building installations and facilities...TR in NW = Technical Test RegulationsTR in Bay = Regulations on testing safety related installations and facilities

(test regulation on safety installations SPrfV)

Remark 1: VDI 3819 Part 1 Fire protection for building technology comprises all titles of regulations with date of issue

Remark 2: If there is no information given in the table, there are either no legal building regulations or there are no exact regulations on lightning protection and corresponding tests.

Table 3.1.1 Legal building regulations of the German Federal states on lightning protection (Part 2)

It is being replaced step by step by thefollowing standard.

DIN EN 50164-1(VDE 0185 Part 201): 2000-02Lightning protection componentsPart 1: Requirements for connectioncomponentsDefines the requirements which metalconnection components such as connec-tors, terminal and bridging components,expansion pieces and measuring pointsfor lightning protection systems have tomeet.

DIN EN 50164-2(VDE 0185 Part 202): 2003-05 Part 2:Requirements for conductors and earthelectrodesThis standard describes, for example,dimensions and tolerances for metal con-ductors and earthing electrodes as wellas the test requirements of the electricaland mechanical values of the materials.

Special standards for earth-terminationsystems:

DIN 18014: 1994-02Foundation earth electrodeThis directive provides information aboutthe arrangement and the installation offoundation earthing electrodes withpractical application examples.

DIN VDE 0151: 1986-06Material and minimum dimensions ofearthing electrodes with respect to cor-rosionThis VDE guideline applies to corrosionprotection when installing and extend-ing earthing electrodes and earthing-ter-mination systems. It provides informa-tion on how to avoid or reduce the risk ofcorrosion to earthing electrodes andwith earthing electrodes of other systemsinstalled. Moreover, it provides informa-tion to assist in making the correct choiceof earthing electrode materials, and alsoabout special anticorrosion measures.

DIN VDE 0150: 1983-04Protection against corrosion due to straycurrents of d.c. installationSubclause 4.1.4.2 requires that, forunderground storage tanks electricallyseparate from domestic installations byvirtue of their being fitted with insulat-ing parts, the connection between thetank and the lightning protection systemmust be effected by means of an isolat-ing spark gap.

DIN VDE 0101: 2000-01Power installations exceeding 1 kVSubclauses 5.2.5 and 7.5 deal with surgeprotection and lightning protection.

DIN VDE 0141: 2000-01Earthing system for special power instal-lations with nominal voltages above 1 kVSection 6 "Earthing to protect againstthe effects of lightning, gives specialconsideration to the requirements oflightning protection.Reference is made to the risk of backflashover, and a relationship is estab-lished between the impulse earthingresistance of the mast or structure earth-ing, the impulse withstand voltage of theinsulation and the peak value of thelightning current.Section 6.3 draws attention to the factthat it is more effective to install severalindividual earthing electrodes (meshedor star-type earthing electrodes) than asingle, very long earth rod or surfaceearthing electrode.

Special standards for internal lightningand surge protection, equipotentialbonding

In the VDE 0100 series of standards, thefollowing parts have to be taken intoconsideration:

DIN VDE 0100 Part 410: 1997-01Erection of power installations withnominal voltages up to 1000 V Part 4: Protection for safetySubclauses 413.1.2 and 413.1.6 describeprotective measures in the event of indi-rect contact (equipotential bonding).

DIN VDE 0100 Teil 540: 1991-11Erection of power installations withnominal voltages up to 1000 VSelection and erection of equipmentEarthing arrangements, protectiveconductors, equipotential bonding con-ductors.Contains the provisions for the installa-tion of earth-termination systems andthe measures for equipotential bonding(main earthing busbar, supplementaryequipotential bonding).

DIN VDE 0100 Part 534: 1999-04Electrical installations of buildings Part534: Selection and erection of equipment Devices for protection against overvolt-agesThis standard deals with the use of surgeprotective devices Type I, II and III in lowvoltage consumer is installations in accor-dance with the protection in the event ofindirect contact.

DIN VDE 0100 Part 443: 2001-02Erection of low voltage installationsProtection for safety Protection againstovervoltages of atmospheric origin ordue to switching

DIN VDE 0110: 1997-04Isolation coordination for equipmentwithin low-voltage systemsPart 1: Principles, requirements and testsThis standard defines the minimum insu-lation distances, their selection and therated impulse voltages for overvoltagecategories I to IV. These values form thebasis for the use of surge protectivedevices in accordance with E DIN VDE0675 Part 6: 1989-11.

VDEW Directive: 1998-01Surge protective devices Class BDirective for the use in main distributionsystemsDescribes the use and the installation ofsurge protective devices Type I in theupstream area of the meter

Especially for electronic systems such astelevision, radio, data systems tech-nology (telecommunications systems)

DIN VDE 0800 Part 1: 1989-05General concepts; requirements and testsfor the safety of facilities and apparatus

DIN VDE 0800 Part 2: 1985-07Earthing and equipotential bondingPart 2 summarises all requirements onthe function of a telecommunicationssystem with respect to earthing andequipotential bonding.

DIN VDE 0800 Part 10: 1991-03Transitional requiremenets on erectionand operation of installationsPart 10 contains requirements for theinstallation, extension, modification andoperation of telecommunications sys-tems. Section 6 of this part lays down therequirements for surge protective meas-ures.

DIN VDE 0845 Part 3-1: 2002-03Surge protective devices connected totelecommunications and signalling net-works Performance requirements andtesting methods

DIN VDE 0855 Part 1: 1994-03Cable networks for television signals,sound signals and interactive services;Safety requirementsSection 10 of Part 1 lays down therequirements for measures to protectagainst atmospheric discharges (earthingof the antenna mounting, equipotentialbonding).

VDE 0855 Part 300: 2002-07Transmitting/ receiving systems for trans-mitter RF output power up to 1 kW; Safety requirementsSection 12 of Part 300 describes the light-ning and surge protection and the earth-ing of antenna systems.

www.dehn.de

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DIN EN 61663-1 (VDE 0845 Part 4-1):2000-07Telecommunication lines, Part 1: Fibreoptic installationsOn this subject, the standard describes amethod for calculating the possible num-ber of incidences of damage for selectingthe protective measures which can beused, and gives the permissible fre-quency of incidences of damage. Onlyprimary faults (interruption of opera-tions) and not secondary faults (damageto the cable sheath (formation of holes)),however, are considered.

DIN EN 61663-2 (VDE 0845 Part 4-2):2002-07Telecommunication lines, Part 2: Linesusing metallic conductors. This standard must only be applied to thelightning protection of telecommunica-tion and signal lines with metal conduc-tors which are located outside buildings(e. g. access networks of the landlineproviders, lines between buildings).

Inspection of lightning protection sys-tems

DIN V VDE V 0185-3 (VDE V 0185 Part 3):2002-11Physical damage to structures and lifehazardMain section 3: Inspection and mainte-nance of lightning protection systemsThis describes the procedure for inspec-tions and maintenance. This standardapplies to new and old installations,which are considered in a general sense.

Special installations

DIN EN 1127-1: 1997-10Explosion prevention and protection -Part 1: Basic concepts and methodologyThis standard is a guide on how to pre-vent explosions, and protect against theeffects of explosions by employing meas-ures during the drafting and design ofdevices, protection systems and compo-nents.Sections 5.3.8 and 6.4.8 basically laydown the requirement for protectionagainst the effects of a lightning strokewhich put the installations at risk.

DIN EN 60079-14/VDE 0165 Part 1: 1998-08Electrical apparatus for explosive gasatmospheresSection 6.5 draws attention to the factthat the effects of lightning strokes mustbe taken into consideration.Section 12.3 describes the detailed stipu-lations for installations for the ex zone 0.Extremely extensive equipotential bond-ing is required in all ex zones.

DIN 50281-1-2 VDE 0165 Part 2: 1999-11Electrical apparatus for use in the pres-ence of combustible dustElectrical apparatus protected by enclo-sures; Selection, installation and mainte-nance

VDE document series 65: ElectricalExplosionsschutz nach DIN VDE 0165;VDE Verlag Berlin [engl.: Electricalexplosion protection according to DINVDE 0165], Annex 9: PTB-Merkblatt frden Blitzschutz an eigensicherenStromkreisen, die in Behlter mitbrennbaren Flssigkeiten eingefhrtsind [engl.: PTB bulletin for protectionof intrinsically safe circuits installed incontainers with flammable liquidsagainst lightning]

Standards can be obtained from the fol-lowing address:

VDE VERLAG GMBHBismarckstrae 3310625 BerlinGermanyPhone: +49 30 34 80 01-0Fax: +49 30 341 70 93eMail: [email protected]: www.vde-verlag.de

or

Beuth-Verlag GmbHBurggrafenstrae 4-1010787 BerlinG

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