Earthing Systems Guide

Earthing systems guide

Planning, execution and practical implementation

Building Connections

OBO Construct planning aids

Digital selection aids for earthing systems and OBO Construct for earthing systems surge protection The digital selection aid can be used for the easy The OBO Construct electronic planning aids are pro- planning and configuration of earthing systems. The grams developed to support electrical installation en- simple and intuitive user guidance leads you through gineers and planners in the design of electrical install- the individual components of the earthing system step ation systems. In particular, in complex areas such as by step. The software then automatically calculates surge protection and earthing, there are countless the amounts required and the matching accessories. technical and standard general conditions to be ob- The application can be opened on any end device ir- served. The two OBO Construct programs for earthing respective of its operating system – be it smartphone, and surge protection systems should provide active tablet or desktop PC. help here. Systematic questions simplify the search for suitable products and guaranteed surge protection systems and earthing systems which fulfil the standards.

Benefits • Time and place-independent work assistance • Transmit planning requirements to complete product systems • Find suitable products quickly and simply • Calculate material and parts lists automatically • Download configuration results as Excel or Word files TBS Leitfaden Erdungssysteme / en / 2020/04/02 11:50:11 11:50:11 (LLExport_02640) / 2020/04/02 11:50:33 11:50:33

2 TBS Leitfaden Erdungssysteme / en / 2020/04/02 11:50:11 11:50:11 (LLExport_02640) / 2020/04/02 11:50:33 11:50:33 pleteness. com- to claim no make and binding legally not are contents The experience. our on and regulations, and rules valid and known currently the on based is guide This Contents 6. 5. 4. 3.10 3.9 3.8 3.7 3.6 3.5.2 3.5.1 3.5 3.4 3.3 3.2 3.1 3. 2. 1. 7. Conclusion Documentation Earthing systems for wind power plants Antenna earthing according to VDE 0855-1 (EN/IEC 60728-11) Short-circuit current carrying capacity of earthing components (50 Hz) Touch voltage Potential control against step voltages Ring earther Earth rod Lightning protection earthing Insulated earthing systems Labelling the connection lugs Foundation earth electrodes Individual foundations Earthing systems and their materials Normative requirements Basic principles Literature notes 62305-3 (VDE 0185-305-3) OBO selection aid for foundation and ring earthers according to DIN 18014 and IEC/EN – type A – type B 3 28 28 27 25 23 21 20 18 17 15 14 30 9 8 6 6 5 4 4 1. Basic principles

The earthing system is the basis for the safe function Note of every electrical system and its protection devices. It Section 542.1.1 of IEC 60364-5-54: "For protection ensures operation and protects people against haz- and function purposes, earthing systems may be used ardous currents. Buildings with IT systems and data together or separately, according to the requirements cabling have high requirements for electromagnetic of the electrical system. The protection requirements compatibility measures (EMC). To ensure the EMC must always have priority." shield and personal protection, meshed equipotential bonding and a low-ohmic earthing system integrated The earthing system thus represents a safety-relevant in the structure are required. part, and installation is only permitted if performed by an electrical or lightning protection specialist. In addition, the responsible specialist must be stated in the prescribed documentation.

The following infringements of the rules of technology are specified in § 319 "Causing danger during construction work" of the German Criminal Code: 1. Whosoever, in the planning, management or execu- 2. Normative requirements tion of the construction or the demolition of a structure, violates generally accepted engineering standards and thereby endangers the life or limb of an- The earthing system creates the electrical connection other person shall be liable to imprisonment not ex- to the surrounding earth. The earthing resistance of ceeding five years or a fine. the system should be as small as possible (less than 2. Whosoever, in engaging in a profession or trade, vi- 10 Ω) and must be coordinated with further protective olates generally accepted engineering standards in measures and switch-off conditions. the planning, management or execution of a project to install technical fixtures in a structure or to modi- The equipotential bonding based on the earthing sys- fy installed fixtures of this nature and thereby en- tem fulfils the following functions: dangers the life or limb of another person shall in- • Protection against electric shock ‒ IEC 60364-4-41 cur the same penalty. • Protective equipotential bonding ‒ IEC 60364-5-54 3. Whosoever causes the danger negligently, shall be • Lightning protection equipotential bonding ‒ IEC liable to imprisonment not exceeding three years or 62305 a fine • Energy systems and surge protection ‒ IEC 60364- 4. Whosoever, in cases under subsections (1) and (2) 4-44 above, acts negligently and causes the danger neg- • Low-voltage electrical installations – IEC 60364-5- ligently shall be liable to imprisonment not exceed- 54 ing two years or a fine. • Data cabling and shielding – EN 50310 • Electromagnetic compatibility ‒ EMC Directive 2004/108/EC (EMVG) The earthing system is a part of the electrical system. • Antenna earthing – IEC 60728 Only electrical or lightning protection specialists may • Application of equipotential bonding and earthing in install, check and accept the earthing system. Con- buildings with information technology equipment ‒ struction companies must allow the supervision of the EN 50310 installation and acceptance of the earthing system by • Electrical installations in residential buildings – DIN electrical and lightning protection specialists. 18015-1 • Foundation earth electrodes‒ DIN 18014

In Germany, the foundation earth electrode in new buildings must meet the requirements of DIN 18014 and the technical connection conditions (TAB) of the power supply generator (VNB). TBS Leitfaden Erdungssysteme / en / 2020/04/02 11:50:11 11:50:11 (LLExport_02640) / 2020/04/02 11:50:33 11:50:33

4 TBS Leitfaden Erdungssysteme / en / 2020/04/02 11:50:11 11:50:11 (LLExport_02640) / 2020/04/02 11:50:33 11:50:33 • • – requiredthefindcanWe definitions 60050-826IECin What do we mean by an "earthing system"? an earthing system. include must system each that specifystandards The als materi- their and systems Earthing 3. Installing a foundation earth electrode Low-voltage electrical installations: Terms. contact with the earth." another specific conductive medium in electrical "Conductive element, embedded in the earth or in source." Also: ment used to earth a network, a system or a re- "Totality of the electrical connections and equip- • • • • • earthing system: created improperly an of Consequences • • • The tasks of an earthing system are: energy Electrical decoupling of high amounts of lightning made connections (no terminal connection) Destruction of the foundation through improperly resting area of the energy-rich lightning current Destruction of the foundation through insufficient ar- No even potential course on the earthing system bonding Dangerous surge voltages at the equipotential building structure Equipotential bonding near conductive walls of the ors Equipotential bonding between the down-conduct- Arresting of the lightning current into the earth 5 Type B foundation earth electrode

Flat conductor 3.1 Individual foundations

Cross-connector with corrosion protection

Corrosion protection strip Individual foundations, e.g. for supports, must have a foundation earth electrode with a length of at least Connection terminal for reinforced steels 2.5 m. These foundations should be conductively con- Cross-connector nected and the maximum grid width of 20 x 20 m may not be exceeded. The corrosion resistance of the Earth lead-in rod individual foundations and the connection cables must Earthing fixed point be ensured using suitable measures and materials.

Main earthing busbar (MEB)

3.2 Foundation earth electrodes

A foundation earth electrode is a closed ring, ideally consisting of flat conductors or, alternatively, of round conductors, with a maximum grid width of 20 x 20 m. The foundation earth electrode is connected to the reinforcement at a spacing of approx. 2 m using clamp- ing connectors. To ensure corrosion protection, the foundation earth electrode must be embedded in the concrete with a jacket of at least 5 cm. The concrete sets up the electrical connection between the foundation earth electrode and the earth. TBS Leitfaden Erdungssysteme / en / 2020/04/02 11:50:11 11:50:11 (LLExport_02640) / 2020/04/02 11:50:33 11:50:33

6 TBS Leitfaden Erdungssysteme / en / 2020/04/02 11:50:11 11:50:11 (LLExport_02640) / 2020/04/02 11:50:33 11:50:33 rosion protection strip. Connections in the earth must be protected with a cor- or Note! (1.1.4404/316L V4A quality 1.4571/316Ti) must be created. steel stainless of earther ring cm a concreting, 5 Before jacket. a concrete with requirements protection corrosion the fulfil not do concrete fibre steel of made plates Floor Note! standard VDE 0185-561-2 ed. 2 (IEC 62561-2). componentsprotectionlightningthe or62305-3) (IEC lightningprotection standard VDE 0185-305-3 Table 7 the to correspondmust materials The foundation. the from protrude down-conductorsmust the for required lugs connection the system, protection lightning the lightningprotection earther. Toallow the connection of a asused be foundation alsoelectrodeTheearthcan ally only 5 x 5 m (VDE 0185-305-4/IEC 62305-4). usu- but imped-m, 20 x the20 be not may reduce width grid the ance, to case, this foundation compatibility In powerful electrode. earth a electromagnetic require requirements high (EMC) with Systems Note! equipotential functional the to bonding conductor of the foundation. connected is earth the with contact in earther ring This foundation. crete earther ring con-beneathadditionallymustoutsidetheusedor be a case, this In overhangs. roof large of This case the foundation.in particularly account into thetaken be should outside earth frost-free ring moist, the in earth the with resistance,contact in attached be must earthing earther constant achieve To trough. white a as or insulationperimeter with trough, insulation extent.case,example,thefor TheThisis versions blackwith a as great a to earth. out dries concrete the the that means to no be connection need there electrical then insulated, is concrete the If nections. con- secure considered are example, for connectors, mechanicallycompactedin concrete.Screwed-onuse for approved not are connectors wedge 18014, DIN standard electrode earth foundation the to According Note! steel in earth and concrete. e.g. environments,distinct two in embedded is metal of typesingle awhenoccur alsocan Itmolten salt.or water soil, in another one with connected are metals Electrochemicaldifferentrode.whencorrosionoccurs Allmetals contactin withtheground wateror can cor- • • • Materials • • Dimensions Versions of foundation earth electrodes the maximum short-circuit currents which occur. stateslargerthatcross-sections necessarybemay for 1 o tasomr ttos VE 11 E 61936) (EN 0101 VDE stations, transformer For in the earth) Copper (can be used in concrete jackets or directly concrete jackets or directly in the earth) 1.4404/316L or 1.4571/316Ti (can be used in Stainless steel of quality V4A, e.g. material no. least 5 cm concrete cladding) Bright and non-galvanised steel (use only with at Strip steel (min. dimensions 30 mm x 3.5 mm) Round steel (min. diameter 10 mm) 1 7 1 Minimum dimensions Material Form Earth rod Earth conductor Earth plates Cable 50 mm² Round, solid Ø 8 mm Strip, solid 20 x 2.5 mm Copper Tin plated copper Round, solid Ø 15 mm Pipe Ø 20 mm Solid sheet 500 x 500 mm Grid mesh 600 x 600 mm Round, solid Ø 10 mm Round, solid Ø 14 mm Pipe Ø 25 mm Hot galvanised steel Strip, solid 30 x 3 mm Solid sheet 500 x 500 mm Grid mesh 600 x 600 mm Profile (a) 290 mm² Cable Ø8 mm 70 mm² Bright steel (b) Round, solid Ø 10 mm Strip, solid 25 x 3 mm Round, solid (c) Ø14 mm Round, solid (c) Ø 8 mm Copper-coated steel Round, solid (d) Ø 10 mm Strip, solid 30 x 3 mm Round, solid Ø 10 mm Rustproof steel (e) Round, solid Ø 15 mm Strip, solid 30 x 3.5 mm

(a) Various profiles with a cross-section of 290 mm² and a minimum thickness of 3 mm are permitted, e.g. cross profiles (b) Must be embedded in concrete to a depth of at least 50 mm (c) With at least 250 μm copper support with 99.99% copper content (d) With at least 70 μm copper support with 99.99% copper content (e) Chromium ≥ 16%; nickel ≥ 5%; molybdenum ≥ 2%; carbon ≤ 0.08%

Materials, form and cross-section of earthers according to VDE 0185-561-2 ed. 2

3.3 Labelling the connection lugs

During the construction phase, metal connection lugs pose a risk of injury to people. For this reason, the connection lugs of the earthing system must be marked clearly during the entire construction phase (DIN 18014).

Protective cap for flat and round conductors, retroreflective ProtectionBall, item no. 5018014 TBS Leitfaden Erdungssysteme / en / 2020/04/02 11:50:11 11:50:11 (LLExport_02640) / 2020/04/02 11:50:33 11:50:33

8 TBS Leitfaden Erdungssysteme / en / 2020/04/02 11:50:11 11:50:11 (LLExport_02640) / 2020/04/02 11:50:33 11:50:33 • • • • sions: ver- following the with case the insulation example, for is, extent. TheThis great a to earth. out dries concrete the the that means to no be connection need there electrical then insulated, is concrete the If systems earthing Insulated 3.4 Insulated floor plate (perimeter insulation, shown here in blue) made of recycled material or crushed glass Poorly electrically conductive earth strata, e.g. DIN 206-1 and 1045-2 of the quality White trough: Water-impermeable (WU) concrete to modified bitumen thick coating (KMB) Black trough: Seals with bitumen strips or polymer- side and side walls of the foundations Perimeter insulation: Heat insulation on the under- ≥ C25/30 must be installed before the concrete work. Forthisreason, largein buildings, theearthing system Note! • • following thegrid width must be maintained: then foundation, insulated the of floor plate the under installed is earther the If foundation. the of conductor bonding equipotentialfunctional the to connected is earth the with contact in earther ring be additionally must beneathusedoutsideconcrete eartherorthe foundation. This ring a cases, these In 20 x 20 m without lightning protection measures 10 x 10 m with lightning protection measures 9 Perimeter insulation Perimeter insulation only on the surrounding walls Perimeter insulation is created from heat-insulation If the perimeter insulation is only on the surrounding plates and is used beneath floor plates and on cellar walls, earther contact is often still intact. The founda- walls. The use of perimeter insulation does not create tion earth electrode can be implemented in the con- an electrically conductive connection between the crete. To ensure contact with the earth, no water-im- concrete foundation and the earth. permeable concrete (WU concrete) may be used.

Perimeter insulation surrounding on all sides If all the walls, foundations and the bottom of the foundation are surrounded by the perimeter insulation of the structure, then the function of the foundation earth electrode will be restricted or non-existent. For this reason, with insulated foundations, a ring earther must be installed in contact with the earth beneath the foundation and the insulation, in order to guarantee the standard-conformant function of the earthing system. Before installing the perimeter insulation, the earther of stainless steel quality V4A (1.4404/316L or 1.4571/316Ti) must be erected. TBS Leitfaden Erdungssysteme / en / 2020/04/02 11:50:11 11:50:11 (LLExport_02640) / 2020/04/02 11:50:33 11:50:33

10 TBS Leitfaden Erdungssysteme / en / 2020/04/02 11:50:11 11:50:11 (LLExport_02640) / 2020/04/02 11:50:33 11:50:33 nection on each down-conductor. con- a be should there system,protection lightning a is therebuilding.metresperipherytheIfaround the of 20 be should connections the between spacing um maxim- build-thesystem,protection lightning a withoutings On other. each to connected be should tems thecleanliness in layer ortheinearth. Both earthing installedsys- width grid same the least earthing at second with system a be must there seal, the Beneath bonding. equipotentialfor used is trough black the within trode elec- earth foundation The foundation. the in created ring gridbe must bonding additionalequipotential functional and anearther here, earth the has with longer contact no electrode this earth in foundation Because, the trough". case, "black a as known is this seal, plastic or bitumen a by sides all on surrounded is earth the with contact in building the of area the If Black trough Black trough protection corrosion as used is cladding concrete cm 5 Min. Spacer layer Blinding electrode earth Ring level groundwater Maximum m 1.50 min. lug, Connection 11 White trough A "white trough" is a construction consisting of water- impermeable concrete (WU concrete), in which water cannot penetrate right through the concrete. As with the black trough, there is no contact between the earth and the foundation earth electrode.

If there is a lightning protection system and an insulated foundation, two earthing systems must be installed: • In the foundation: One earther with a 20 x 20 m grid width, in accordance with the foundation earth electrode standard DIN 18014. • In the earth: One earther with a 10 x 10 m grid width, in accordance with the lightning protection standard VDE 0185-305-3 (IEC 62305-3)

White trough

Connection lug, min. 1.50 m

Maximum groundwater level

Ring earth electrode

Blinding layer

Spacer Min. 5 cm concrete cladding is used as corrosion protection TBS Leitfaden Erdungssysteme / en / 2020/04/02 11:50:11 11:50:11 (LLExport_02640) / 2020/04/02 11:50:33 11:50:33

12 TBS Leitfaden Erdungssysteme / en / 2020/04/02 11:50:11 11:50:11 (LLExport_02640) / 2020/04/02 11:50:33 11:50:33 Expansion strip, type 1807 DB, item no. 5016160 item no. 2360041 Sealing sleeve for round conductors, type DW RD10, for 72 hours. must be tested with at least 1 bar of pressurised water sleeves sealing 2, ed. 0185-561-5 VDE to According pillary ingress of water into the concrete. water- pressure tested sealing sleeve a must be used. It prevents the necessary, ca- is groundwater the of groundwater highest the area the insertioninstructural reasons,anfor If, level. above place take should building the into lugs connection the of insertion The strips expansion and pieces expansion sleeves, Sealing o as h fudto erh lcrd truh the through electrodemovement joint in expanded systems. earth foundation the pass to used be canexpansion strippossible, an not is this If be can point piece. connection The expansionan mm².of use thethrough time any atchecked 50 least parts at bridging of cross-section flexible a with aluminium or copper of with made connected and points fixed earthing Connection with wall the joints. of out run movement be should lugs over run be electrode not earth may foundation the concrete, the Within Bridging of movement joints with an expansion piece Expansion piece, type 1807, item no. 5016142 13 3.5 Lightning protection earthing

The earthing system distributes the lightning current in If there is a lightning strike, a large voltage de-ener- the earth. A low earthing resistance (less than 10 Ω) gises at the earthing resistor of the building. This is recommended. To minimise potential differences, all voltage, de-energised by the building, generates a the system parts, such as the lightning protection, voltage funnel in the earth, endangering the people power supply and IT systems, must be connected to above it. At points with increased numbers of people, the same earthing system. The earthing system must these hazardous potential differences should be re- arrest the lightning current into the earth with a low duced by installing additional parallel and meshed resistance, in order to avoid surge voltages. The ex- conductors around the foundation earth electrode as ternal lightning protection system is connected to the ring earthers in the earth. earth via the earthing system.

Type A Type B • Horizontal earth electrodes • Ring earth electrodes (surface earthers) • Vertical earth electrodes (earth rods) • Foundation earth electrodes

External and internal lightning protection systems

Earth rod, type A Earth rods (optional)

Underground connection Underground connection

Main earthing rail (MER) Main earthing busbar (MEB)

Earthing system, type A: Connection outside the building Installation principle, ring earther structure TBS Leitfaden Erdungssysteme / en / 2020/04/02 11:50:11 11:50:11 (LLExport_02640) / 2020/04/02 11:50:33 11:50:33

14 TBS Leitfaden Erdungssysteme / en / 2020/04/02 11:50:11 11:50:11 (LLExport_02640) / 2020/04/02 11:50:33 11:50:33 Type A earth rods with ring equipotential bonding 10 under of resistance measured a With reduced.also is voltagestep the andcreated is earth manently moist areas in the earth. per- Good contact to the the reaches This m. 9 is depth The installation ideal earth. the into vertically inserted are rods Earth rod Earth 3.5.1 istance must be checked on installation. earthingresistance smallato extent. Theearthing res- stallationdepth ofthe earth rod often only reduces the in- greater Aassumed. be can depthinstallation cient Earth rods (observe corrosion protection for connectors) for protection corrosion (observe rods Earth clips Connection conductor Round strip protection Corrosion Cross-connector – type A type Ω a suffi- a , take place alsoin the building (cellar). can this then building, the outside possible not connectionis the If earther.building the toconnected interconnectedand be must rods earthindividual The Note! earthers. earthers parallelinserted the of length the the least at correspondto must of spacing the rods, earth the earthrods multiple iswise. To minimise the mutual influence of of installation parallel depth, installation ing earthingtheincreas-resistancereduced anIfnot at is 15 Type: OMEX With soft metal inlay and hardened hexagonal pin for difficult soil conditions.

Type: BP Very good contact properties through soft metal inlay in the bore.

Type: Standard With double (Ø 20 mm) or triple (Ø 25 mm) knurling for strain-resistant connections.

Type: LightEarth Earth rod with very little weight for light to medium-heavy ground conditions.

OBO earth rod versions

Earth rods are differentiated according to the type of connection of the individual earth rods, the external diameter, and the material.

Earth rods consist of combinable individual rods of length 1.5 m. The connection is made using a coupling consisting of a hole and stud. This has the ad- vantage that the coupling closes automatically at the time of installation and creates a secure connection from both a mechanical and an electrical point of view. When an earth rod is driven in, this compacts the ground around it. This is conducive to a good electrical contact.

Striking tools are generally used for driving in the earth rods. The possible penetration depth of the earth rods depends on various geological factors. Cross-section through the coupling of an OBO earth rod TBS Leitfaden Erdungssysteme / en / 2020/04/02 11:50:11 11:50:11 (LLExport_02640) / 2020/04/02 11:50:33 11:50:33

16 TBS Leitfaden Erdungssysteme / en / 2020/04/02 11:50:11 11:50:11 (LLExport_02640) / 2020/04/02 11:50:33 11:50:33 Type B ring earth electrode or (1.4404/316L V4A quality 1.4571/316Ti) may be installed. steel stainless the only earth, the in that, stipulates18014 DIN standard of corrosionprotection,thefoundationearthelectrode reasonsstructure.For thearound earth the increated steel, round or strip of ring closed a is earther ring A earther Ring 3.5.2 Flat conductor Flat Cross-connector Earth lead-in rod lead-in Earth strip protection Corrosion conductor Round – type B type tance of 1.0 metres to the building. be atleast0.5metresdeep(frostdepth)andadis- shouldRoutinglength. its of 80% least at along earth the with contact direct have should earther ring The Note! 17 3.6 Potential control against step voltages The step voltage is the voltage between a person’s The lightning current is distributed through the metallic feet placed 1 m apart. Here, the compensating current earthing system. Additional earth rods at the outer flows between the person's feet through their body. edges of the potential control conduct the majority of According to the state of the art, a value of 25 kV the current into the earth. The voltage drop on the (10/350) is assumed as the lethal limit value. Equally earth's surface and the resulting step voltage are re- important, as with any earthing system, is the specific duced. Here, stainless steel of quality V4A earth resistance ρE. In entrance areas or in front of (1.4404/316L or 1.4571/316Ti) should be used as a lookout towers, a densely looped earthing system is material. installed to minimise step voltage and to protect people. Option 1: Potential control through ring earthers Additional ring earthers are routed around the foundation earth electrode and connected with one another in a grid format. As the distance from the rod or down- conductor increases, the ring earther is routed 0.5 m deeper each time at the usual spacing of 3 m.

Potential control on a street-light pole

Earthing voltage UE With potential control

Without potential control TBS Leitfaden Erdungssysteme / en / 2020/04/02 11:50:11 11:50:11 (LLExport_02640) / 2020/04/02 11:50:33 11:50:33

18 TBS Leitfaden Erdungssysteme / en / 2020/04/02 11:50:11 11:50:11 (LLExport_02640) / 2020/04/02 11:50:33 11:50:33 Mesh grid for potential control V4A (1.4404/316L or 1.4571/316Ti) is necessary. earth,high-qualitytheusesionofthein stainless steel corro-minimisetheToedge. the atditionalrods earth with aspecificearthresistanceof1,000Ohmandad- limit the below value m 10 x 10eartherring of(10/350) a kVvalue (25for a to reduced be step the can m, 0.5 voltage x 0.5 of width grid a with even that width grid show the maysimulation aexample, For above. specified from deviate may and software, tion simula- using calculation detailed a with determined be canrequired width grid actual The m. 0.25 x 0.25 of width grid maximum a and mm 3 of diameter um earth'ssurface.metalThemeshminim- shouldhave a the belowm) 0.25max. to m 0.1 a (from depthshallow at installed is mesh The wise. is grid metal tight a transportrefugesorstops,Inpotential control through Option 2: Potential control through mesh grid protection against dangerous contact voltage. h tse isCon tested The (step installed drop be voltage should here. rods highest earth the Additional voltage). in results which earth, the into flows current the The of proportion mesh. largest the of edges the at expected be to is ity endthegrids.of This means thehighest current dens- the at directly compacted are lines equipotential The Note! touch as voltage, well and reduces the risk to as people. metre, re- per voltage greatly step system the duces meshed tightly This system. ing earth-existingthe connectedto andterminalsnection con-usingothereach screwed to aregrids mesh The Testing of the isCon ® ® r+ odco poie further provides conductor Pro+ Pro+ conductor 19 3.7 Touch voltage

If there is a lightning stroke, the lightning current is Note! routed through the down-conductors into the earthing If a control earther or the insulation around the down- system and the earth. The resistance of the down-con- conductor is not possible, then barriers must be cre- ductor and the earth causes a voltage drop, which ated or warning information attached. can lead to so-called touch voltage. The touch voltage is the voltage between a component (e.g. the down- Technical solution conductor) and earth potential. The current flows from The isCon® Pro+ conductor (5407995, 5407997) from the hand to the foot through the body. The potential OBO meets the requirements of VDE 0185 305-3 (IEC hazard must be reduced by technical measures, e.g. a 62305-3) as a protective measure against dangerous control earther. touch voltages! It has been independently tested with a withstand voltage (-100 kV, 1.2/50 µs) under irriga- tion according to VDE 0432-1 (IEC/EN 60060-1).

UE: Earthing voltage

UB1: Touch voltage without potential control (on foundation earth electrode)

UB2: Touch voltage with potential control (foundation earth electrode and control earther)

Us: Step voltage (without control earther) φ: Earth surface potential

FE: Foundation earth electrode

SE: Control earth electrode (ring earth electrode)

1m B2 U

B1 FE SE

U FE E S U U

Electrical potential on the earth surface and voltages as current passes through the foundation earth electrode (FE) and control earther (SE) TBS Leitfaden Erdungssysteme / en / 2020/04/02 11:50:11 11:50:11 (LLExport_02640) / 2020/04/02 11:50:33 11:50:33

20 TBS Leitfaden Erdungssysteme / en / 2020/04/02 11:50:11 11:50:11 (LLExport_02640) / 2020/04/02 11:50:33 11:50:33 earthing system of 300 °C are used as a basis. the in used components the of temperature missible per- maximum the and second 1 of time) (switch-off tionstheinproject, theduration oftheresidual current specifica- particular no are there If short-circuit. earth double a of effects dangerous the controls that a way in constructed and planned be must associated components all and systems earthing of types These in Hz. 60 to frequencyratedup a and kV 1 overvoltage systems earthing for heavy-currentACratedinstallationsnetworksa within requirements special the considering for basis the is 50522) (EN 0101-2 VDE Hz) (50 components earthing of pacity ca- carrying current Short-circuit 3.8 Short-circuit current test on earth rod terminal materialsfor the duration of the residual current flow t earther for (G) density currentshort-circuit Hz 50 ible permiss- The purpose. this for tested been have componentsthat connection and rods earth offers OBO Short-circuit current test on earth rod pacity of earther materials". ca- carrying "Current diagram the from taken be can 21 F Current carrying capacity of earther materials 50522). ing earth- or earthersround cross-section requiredof The 150 additional detailed current G = short-circuit current density (A/mm²) strips °C divided Stainless steel V4A (1.4404/1.457 1) (1.4404/1.457 V4A steel Stainless steel Galvanised Copper or calculation, is max. 22 200 calculated by final °C, the is including temperatures, described short-circuit from the conversion potential in current such VDE as 0101-2 short-circuit factors density. 100 (EN for °C, A t F = duration of the residual current (s)

TBS Leitfaden Erdungssysteme / en / 2020/04/02 11:50:11 11:50:11 (LLExport_02640) / 2020/04/02 11:50:33 11:50:33 TBS Leitfaden Erdungssysteme / en / 2020/04/02 11:50:11 11:50:11 (LLExport_02640) / 2020/04/02 11:50:33 11:50:33 • • • • Connection with two vertical or slanted earth rods 3. e.g. with the foundation earth electrode Connectionwith the earthing system ofthe building, 1. one of the ways listed below: 60728-11),in IEC (EN/0855-1 VDE toaccording out carried be must system antenna the of earthing The 60728-11) (EN/IEC 0855-1 VDE to according earthing Antenna 3.9 at least 1 m away from the foundation at least 0.5 m deep in the ground with at least 3 m distance between them at least 1.5 m long each the earther: earther: the of depth installation Basic * depth) ≥ 0.5 m (frost m 0.5 Earthing of antenna systems • • • Connection with a vertical or slanted earth rod 2. at least 1 m away from foundation at least 0.5 m deep in the ground at least 2.5 m long Earth rod Earth electrode earth Foundation depth) earther: the of depth installation Basic * ≥ 0.5 m (frost m 0.5 23 * Basic installation depth of the earther: ≥0.5 m (frost depth)

4. Connection with at least two horizontal earth rods Natural component such as interconnected reinforced • at least 2.5 m long concrete (5) or metal constructions (6), such as cur- • laid in an angle larger than 60° tain walls of suitable dimensions and material, when • at least 0.5 m deep in the ground they are connected to the building foundation/earthing • at least 1 m away from the foundation system (7).

Ring earther Materials and dimensions Suitable materials have a minimum cross-section of Earthing fixed point 50 mm² for copper or 90 mm² for stainless steel V4A. Reinforcement/steel construction 90 mm² hot-galvanised steel may also be used, if the corrosion conditions in the ground permit. Steel skeleton/steel structures

Building foundation

Earthing of antenna systems TBS Leitfaden Erdungssysteme / en / 2020/04/02 11:50:11 11:50:11 (LLExport_02640) / 2020/04/02 11:50:33 11:50:33

24 TBS Leitfaden Erdungssysteme / en / 2020/04/02 11:50:11 11:50:11 (LLExport_02640) / 2020/04/02 11:50:33 11:50:33 Foundation and ring earthers of a wind power plant be should voltages taken into short-circuit account. possible the then tower, the of vicinity immediate or foot the in station transformera isthere detail.Ifpowerwind plantsinof protection lightning the describes61400-24) (IEC 24 0127- VDE impedance. low at earth the plant into thecurrents power distribute must wind system earthing the the in then (WPP), strike lightning a is there If protection. surge and lightning the the of and components resources electrical the the from to system connection earthing the creates rail earthing main The system. protection lightning systemthe of basis electrical the and the of operation fault-free people, of protection the for basis the is system earthing The plants power wind for systems Earthing 3.10 Ring earther Ring electrode earth Foundation system earthing of the other towers, the as is standard. to connected is this if even system, ing Inwind parks, each tower must possess itsown earth- Note! be guaranteed. switch-offelectricalandconditionsthesystemmust of rods are required. In addition, the protection measures Ω 10 of value a exceed not may stationtransformer the andtowerinterconnectedthe The earthingsystems of . If this is exceeded,isadditional thisearthearthers Ifring or . 25 Earthing system of a wind power plant Working on an earthing system of a wind power plant

Earthing system of a wind power plant with additional buildings

Tower

Reinforced concrete foundation

Meshed earthing in concrete foundation

Earth rod and ring earther

Cable duct

Outbuilding TBS Leitfaden Erdungssysteme / en / 2020/04/02 11:50:11 11:50:11 (LLExport_02640) / 2020/04/02 11:50:33 11:50:33

26 TBS Leitfaden Erdungssysteme / en / 2020/04/02 11:50:11 11:50:11 (LLExport_02640) / 2020/04/02 11:50:33 11:50:33 step voltages"). trance area(seethechapter"Potentialcontrolagainst en- the in earther)(ring control potentialadditional be To protect people and reduce step voltage, there must Note! wide area, minimises potential differences. a over connected system, earthing This network. ing earth- meshed a by connected be must building tion opera- existing the and tower the the of system addition, earthing In WPP. the of tower the be to connected must system earthing The electrode. earth ation ring the a found- of a assystemearthing for an or earth consists the inearther used This WPP. be the must of system arrangement earther B type the I), Appendix 61400-24 (IEC 0127-24 VDE to According Earther, type B: ted to at least two down-conductors on the building. connec- are which earthers, vertical and/or horizontal of consists system earthing A type The example. for technology, measuring or additional offices for housing only buildings, but WPP the the for of used system be earthing cannot arrangement A type the I), Appendix 61400-24 (IEC 0127-24 VDE to According Earther, type A: scribed as follows: (IEC 0185-305-3 powerwindplants(WPP),thesearrangements de-are VDE For B. type and standard A type 62305-3)ofspecifiesearthers protection ning light- The 62305). (EN 0185-305 VDE with cordance ac- in conductors lightning suitable using or directly either bonding equipotential protection lightning the with connected be must WPP the of installations and structuresmetallic616400-24), all (IEC0127-24 VDE to and the lightning According protection standard for wind 60479).power plants this (IEC 0140-479 on VDE to informationrefers provides 61400-24) (IEC 0127-24 VDE 1.4571/316Ti). or (1.4404/316L V4A Earthing quality potential.steelstainless in be must earth the controls in systems which earther ring a by preventedbe voltagescantouch and Hazardous step .Conclusion 5. value resistance continuity a be must There Note! • • • (IEC • 0100-600 VDE must contain the following elements: DIN 60364 systems low-voltage 18014andalso the safety standard fortheerection of DIN standard electrode earth foundation current The Documentation 4. can minimise damage and failures. devices, protection surge and lightning with together system, earthing installed correctly A with. complied be must companygenerating power local the of ives ensured direct- the standards, named be the and art the of must state system earthing the Besidestesting. maintenanceand regular through the of action be protective continued must The correctly. documented. installation and checked implemented the planning, is correct system Besides protection the their when reach aims only can systems switch-off differences Voltage encepotentialgenerated.is safetyTheconditions and created. is refer- a andshorted are earth connectedparts thebetween local the to connection low-resistance and bonding conductive equipotential a system, the with Together system. al Theearthing systembasistheentire theisfor electric- be measured for the first time before concreting. should resistance The parts. connection the between ances Results of the measurements of the earthing resist- Results of the continuity measurements photographs Photos of the installed earthing system with detailed Plans and versions of the connection lugs ‑ ) eur dcmnain Te documentation The documentation. require 6) 27 ≤ 0.2 Ω 6. OBO selection aid for foundation and ring earthers according to DIN 18014 and IEC/EN 62305-3 (VDE 0185-305-3)

Foundation earth electrode ‒ without lightning pro- Earthing material, for use in concrete tection • Surrounded by min. 5 cm of concrete on all sides; ≤ 2 m connect to reinforcement • Grid width max. 20 x 20 m; with EMC protection to VDE 0185-305-4: 5 x 5 m • Unreinforced foundation: Material no. 1.4571/1.4404, V4A

Type PU Item no. Description

5052 60 m 5019347 Strip steel 30 x 3.5 mm FT

1811 l 25 units 5014026 Spacer 400 mm FT

250 A-FT 25 units 5313015 Connector, strip steel with reinforcement FT 1814 FT 25 units 5014468 Terminal on reinforcement to Ø 14 mm

Functional equipotential bonding conductor and 1814 FT D37 25 units 5014469 For reinforcements Ø 16–37 mm ring earther Without lightning protection → Insulating foundation 205 B-M10 VA 25 units 5420008 Earthing fixed point M10

DW RD 10 10 units 2360041 Sealing sleeve for round conductors 10 mm 5011 VA M10 50 units 5334934 End piece for earthing fixed point M10

ProtectionBall 25 units 5018014 Protective cap for connection straps

Earthing and connection material, for use in the earth or cleanli- ness layer • Material no. 1.4571/ 1.4404, V4A; clamps in earth with corrosion protection strip • Min. 0.8 m deep, routing outside drainage shaft, frost apron (moist area) • Grid: Without lightning protection: 20 x 20 m, connection between earth and concrete: Every 20 m, with lightning protection: 10 x 10 m, connection between earth and concrete: Every conductor

Functional equipotential bonding conductor and ring earther Type PU Item no. Description With lightning protection → Insulating foundation RD 10 V4A 60 m 5021642 Round conductor Ø10 mm V4A

5052 V4A 30x3.5 25 m 5018730 Strip steel 30 x 3.5 mm V4A

250 V4A 25 units 5312925 Terminal for round conductor and strip steel 356 10 m 2360101 Corrosion protection strip, width: 100 mm

Material for equipotential bonding

Type PU Item no. Description

1801 VDE 1 unit 5015650 Equipotential busbar, industrial

1809 1 unit 5015073 Equipotential busbar, residential

Foundation earth electrode: Ring earther:

Insulation foundation when: • WU concrete (white trough) for WZ<0.6, from C30/B35, (from C25/B30) → Already possible) • Black/brown trough • Completely enclosed foundation with perimeter insulation or dimpled mem- branes • Additionally attached, capillary-breaking, poorly electrically conductive earth strata, e.g. made of recycling TBS Leitfaden Erdungssysteme / en / 2020/04/02 11:50:11 11:50:11 (LLExport_02640) / 2020/04/02 11:50:33 11:50:33

28 TBS Leitfaden Erdungssysteme / en / 2020/04/02 11:50:11 11:50:11 (LLExport_02640) / 2020/04/02 11:50:33 11:50:33 plate, grid width side the floor plate/insula- Ring earth electrodes out- One connection between the ring earther and functional equipotential bonding cable in lightning protection sys- Functional equipotential bonding cable within the floor tems at least every 20 m; at least one connection per (1.4404/316L or ≤ 1.4571/316Ti) Material V4A, 10 m x 10 m Grid width tion yes resistance exists, e.g. through reinforcement every 2 m trough", "white trough", fully ≤ Increased earth transition 20 m x 20 m and a connection to the measures required? surrounding perimeter Lightning protection Start of planning conductor insulation? "black side the floor plate/insula- Ring earth electrodes out- yes (1.4404/316L or ≤ 1.4571/316Ti) Material V4A, 20 m x 20 m Grid width tion no no Equip each foundation with fore their entrance into the appropriate room. Connection Connection parts for connection to the main earthing rail, nection straps should have a length of at least 1.5 m be- Material with at least 5 cm Individual foundations e.g. A connection of the foundation earth electrodes with the foundations into a closed down-conductors of a lightning protection system, con- a foundation earth electrode of Foundation earth elec- for structural supports trodes of all individual (1.4404/316L or ≤ concrete cover 1.4571/316Ti) ≤ Material V4A, 20 m x 20 m 20 m x 20 m Grid width present? ≤ Measurement and documentation 2.5 m length ring straps must be marked clearly. reinforcement every 2 m yes yes no Material with min. 5 cm concrete cover routed Foundation earth elec- ≤ 20 m x 20 m Grid width of trodes Reinforced foundations yes present? Unreinforced foundations/ concrete cover routed or fibrated concrete/ rolled Material with min. 5 cm made of stainless steel 316, (1.4404/ 316L or Foundation earth elec- foundations made of 1.4571/ 316Ti) ≤ 20 m x 20 m Grid width of concrete trodes 29 no 7. Literature notes

Lightning protection standard • VDE 0185-305 (IEC 62305) Protection against lightning – Part 3: Protection of structural facilities and persons

Lightning protection components standard: • VDE 0185-561-2 (IEC 62561-2 ed. 2) Lightning Protection System Components (LPSC) – Part 2: Requirements for conductors and earth electrodes

Low-voltage electrical installations • VDE 0100 (IEC 60634) Low-voltage electrical installations • VDE 0100-410 (IEC 60634-4-41) Low-voltage electrical installations − Part 4-41: Protection for safety − Protection against electric shock • VDE 0100-534 (IEC 60634-5-534) Selection and erection of electrical equipment − Isolation, switch- ing and control − Clause 534: Devices for protection against transient overvoltages (SPDs) • VDE 0100-540 (IEC 60634-5-54) Selection and erection of electrical resources • VDE 0800-2-310 (EN 50310) Earthing and equipotential bonding in buildings with information technology equipment • DIN VDE 0100-600 (IEC 60364-6) Low-voltage electrical installations – Part 6: Verification

Earthing systems and protective conductors • DIN 18014 Foundation earth electrode • DIN 18015-1 Electrical installations in residential buildings

Antenna systems • VDE 0855-1 (EN/IEC 60728-11) Cable networks for television signals, sound signals and interactive services − Part 11: Safety

Heavy-current installations • VDE 0101-2 (EN 50522) Earthing of power installations exceeding 1 kV a.c.

Wind power plants • VDE 0127-24 (IEC 61400-24) Lightning protection for wind power plants

Lightning protection guide • OBO Bettermann ordering no. 9131970 TBS Leitfaden Erdungssysteme / en / 2020/04/02 11:50:11 11:50:11 (LLExport_02640) / 2020/04/02 11:50:33 11:50:33

30 TBS Leitfaden Erdungssysteme / en / 2020/04/02 11:50:11 11:50:11 (LLExport_02640) / 2020/04/02 11:50:33 11:50:33 • • • • • • • • edition 2nd the in New more easily. and faster protection surge and lightning of field the have protection lightninginstallations planin innovationsto brochure youallowsThe guide. new company's technical the into andflowed standards latest the and course, of lightning and, experience ofThis protection. surge field the in experience of years 90 than more on back look can weBettermann, OBO At installation electrical engineers and technical planners for aid planning and work Reference routed. Safely guide. protection Lightning 534 Explanations of DIN VDE 0100-443 and - according to EN 13501-1 Definition of construction material classes side connection compartment Combination arrestor type 1+2 in mains- Formation of equipotential areas rating recommendation Protection angle calculation and protection ive areas Lightning protection in potentially explos- isCon® conductors and selection aid New high-voltage-resistant, insulation fire protection Lightning and surge protection as part of for download on the OBO website. available also is and 1700 - 89 2373 +49 calling by requested be can guide protectionlightning new The selection and planning aids for the protection as of buildings and systems. well as knowledge, pert ex- and basic both of mixture balanced a contains It 31 OBO Bettermann Holding GmbH & Co. KG P.O. Box 1120 58694 Menden GERMANY

Customer Service Tel.: +49 (0)23 73 89 - 17 00 Fax: +49 (0)23 73 89 - 12 38 [email protected] www.obo-bettermann.com © OBO Bettermann 04/2020 EN 04/2020 Bettermann OBO ©

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