ELEMKO reserves the right to modify, add or remove any information included in this catalogue, if necessary. Every updated version of the catalogue

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2 ' EEMKO reserves the right to modify add or remove any information included in this catalogue if necessary Every updated version of the catalogue automatically cancels all the previous ones Photographs of the products are indicative This catalogue has been compiled only to provide information of our products and their applications and in any case does not form a contract The company assumes no liability for loss or damage which may be caused by incorrect implementation regarding the use of the products included in this catalogue EEMKO company assumes no responsibility for any misprints in this catalogue

3 197 ' бт & E ISO/ IEC ISO 9001 E ISO/IEC Meet EEMKO HISTORY Year of 197 was the start of a successful route for our company with main object the Global Solutions of ightning Protection Covering Protection of structures and buildings against direct lightning strike Surge Overvoltage Protection of electrical & electronic systems Earthing Systems Over the years EEMKO has acquired fundamental knowhow experience and specialisation in the protection of people structures and equipment with high specifications and demands against the catastrophic consequences of lightning ll the above strong arms are coupled with strong financial fundamental the sensitivity and insistence on quality the passion and love of the people who staffed the continuous update on all developments that concern our matters the constant training of personnel the transfer of knowledge and experiences to the world through technical seminars and technical books leading developments and creating lasting relationships of trust The company's share capital amounts to бТ making EEMKO among the most financially powerful companies in Europe in our field EEMKO's premises of 600 sqm in which houses all the services and activities are sqm private land Specifically the company is headquartered in Metamorphosis in ttica while in Thiva is the "Research Center for tests and Developments" which is the largest EEMKO's investment carried out exclusively by Elemko' s funds Research Center for tests and Developments of our company is one of the four in all Europe and has been accredited according to standards E ISO/ IEC 17025In Thessaloniki takes place a branch of the company to serve the needs of our customers in orthern Greece more directly GURTEE EEMKO's experience for more than 40 years The scientific and technical knowledge of EEMKO's staff that have been acquired through continuous training The results of the research we carry out at EEMKO's Testing and Certification Research Center EEMKO's long lasting cooperation with university and private research centers in Greece France Belgium Switzerland the US and the UK The adoption and strict implementation of European and International Standards on ightning Protection Components Surge Protection Devices Earthing The adherence to the procedures of the ISO 9001 The accreditation of EEMKO's laboratory according to Standard EISO/IEC DESIGS & STUDIES EEMKO designs and studies comply strictly with the current European and International Standards Frequently heralded as pioneering with a number of them having been presented at International scientific conferences they include Protection of common and special structures from lightning such as Wind Farms and Photovoltaic installations

4 std 80 std 81 ISO 9001 ( ) & Surge Overvoltage Protection of electrical and electronic systems Surge Overvoltage Protection of telecommunications and telemetry systems Earthing Systems of common and special structures such as Wind Farms and Photovoltaic installations Earthing Systems of Substations according to Standards IEEE std 80 and IEEEstd 81 Financial / technical studies of interrelated projects The drawing up of technical specification of offers TECHIC SUPPORT EEMKOА»s engineers are always available to help you choose the most appropriate technical and financial solution Behind every telephone call you make t your worksite t your facilities In your building Everybody is here to help you ISPECTIO pplied European and International Standards require the regular inspection of installed ightning Protection Systems (internal and external) and Surge Protection Systems depending on the required level of protection for the structure to guarantee their readiness and reliability The inspection involve checking That the system satisfies applied Standards That the system components are in good condition and adhere to existing Standards That any new parts of the building are covered by the existing system That surge overvoltage protection equipment is in good condition That new machinery which has been installed is protected against surge overvoltage Inspections are carried out by EEMKOА»s highly trained engineers and technicians who have a complete knowledge of the applied Standards for ightning Protection Systems and many years of experience in designing and installing them They use highly accurate measuring instruments and devices that are regularly calibrated at special laboratories PROJECT SUPERVISIO Project supervision by EEMKO means constantly checking that the design is properly followed and adhered to and that the appropriate materials and equipment are used as laid down in European and International Standards thus ensuring the reliability of the ightning Protection System the Surge Protection System and the Earthing Systems Project supervision by our company guarantees quality reliability and durability

5 еб еб SURGE PROTECTIVE DEVICES B C/DC (E) (IEC) () ( ) 6164 ( ) Introduction The target of the present catalogue is to become a useful tool for every designer installer and project supervisor in order to select install and use the appropriate product to provide maximum safety and protection against surge overvoltages The present catalogue is divided into four main parts in more detail each part contain Part Surge protective devices s connected to power systems Medium voltage surge arresters industrial type s low voltage s DC surge protectors Part B Surge protective devices s connected to information technology systems s for analogue and digital systems s for telecommunication systems s for RF applications s for combined protection Part C Equipotential bonding and Isolation Spark Gaps ISGs Direct equipotential bonding equipotential bonding through isolation spark gaps explosion proof isolation spark gaps s inspection instruments Part D Shielding techniques against electromagnetic fields Shielded cable trays shielded panels electromagnetic shielding against high C/DC currents ll the products which are described in the present catalogue fulfil the requirements of the latest editions of the valid European (E) International (IEC) and ational (EOT) standards The main reason of preparing this catalogue specifically for surge protection arrives from the issue of the new European and International series of standards E / IEC 6205 which describe the design requirements for a lightning protection system and in particular the standard E / IEC which outlines the design requirements for the internal lightning protection system including surge protection In conjunction with the new series of design standards there where made major amendments to the series of standards describing testing requirements for components and devices that are used in a lightning and surge protection system so that both design and testing standards are inline with each other In particular there are amendments to the European series of standards E (testing requirements for components used in external lightning protection and equipotential bonding) as well as in E 6164 series of standards (testing requirements of power and telecom surge protective devices) EEMKO S as always is 100% inline with the new requirements of the standards and we are ready to perform training and to update all our customers to the new standards dditionally EEMKO S has a complete range of products fit for every purpose that might be required according to the new needs t the technical introduction of the present catalogue the reader can find useful information regarding the application and selection principles of surge protection devices However for more detailed information the reader should refer to the European and International series of standards E / IEC 6205 dditionally EEMKO S has issued technical guides fully updated to the new standards which translate in a simpler manner the standard requirements by giving information on how the user can achieve the desired result as well as to how select the appropriate product by outlining numerous application examples fitting the needs of design engineers installers and project supervisors 4

6 еб еб SURGE PROTECTIVE DEVICES 1 (msадs) UPS (s) (kv) Introduction to surge protection Overvoltages may be generated out of various sources which will consequently have different characteristics and therefore they may require different protection measures Figure 1 describes the most common overvoltages The aim of most of the products that are included in the present catalogue is to reduce switching and lightning overvoltages The temporary overvoltages are generated by poor quality of the power supply and have long duration (msадs) They are generally controlled by voltage stabilizers UPS etc The switching and the lightning overvoltages are known as surge overvoltages and they are characterised by short duration (s) and high absolute values (kv) They can be limited by using surge protective devices Surge overvoltages caused by a lightning discharge are the most destructive and they are also the most difficult to be controlled ominal operating voltage TOV Temporary Overvoltages Switching overvoltages ightning overvoltages 1 Figure 1 Common overvoltages 2 200k 10/50s [ ] Damages caused by lightning discharges lightning strike may cause serious damage to an electrical installation which may lead up to a complete destruction of it as it can be seen in Figure 2 One of the main factors responsible for the size of the damage is the peak current and the waveshape of the lightning discharge ightning is a natural current source The flow of the lightning current generates mainly either by resistive or inductive coupling the surge overvoltages ightning strokes as a natural phenomenon can not be identical with each other since the energy and the shape of them may be different each time However after long investigation and field measurements it has been accepted to consider the peak lightning current to have a value of 200k and a waveshape of 10/50s [E / IEC ] 5

7 еб еб SURGE PROTECTIVE DEVICES ( ) 2 Figure 2 Total damage of an electrical installation due to lightning strike Causes of lightning surge overvoltages Whether there is a direct or indirect lightning discharge on a structure it may cause immediate or gradual damage to the electrical and electronic circuitry that the structure is equipped with Figure illustrates the main causes of generating surge overvoltages either due to direct or indirect lightning strikes Direct lightning strike is considered to be the one which strikes on the structure or on an incoming conductive supply network (ie Electricity Telecom) and indirect are considered the nearby lightning strikes either near to the structure or near to incoming conductive supply network and also cloud to cloud lightning Considering them with respect to the damage that they can cause first is the direct lightning strikes followed by the nearby stroke and the cloud to cloud lightning Cloud to Cloud lightning Direct lightning strike ightning on incoming services Direct lightning strike earby lightning Figure Damage to electrical and electronic circuits due to direct and indirect lightning strikes 6

8 еб еб SURGE PROTECTIVE DEVICES IEC () 50% 50% ( ) s (I ) i I i= I s/n n (n = ) ( ) 50% 166% I = I / => I = 166% ( 4) i s i ( 4 ) 1 2 ( ) v (I ) i (m) v= I i / m (n = 1) (m = 4) ( ) % 50% 125% I = I / 1 (n = 1) => I = 50% i s i = I / 4 (m = 4) => = 125% ( 5) v i v Distribution of lightning current ccording to IEC if a structure receives a direct lightning strike () 50% of the lightning current will discharge through the local earthing system where as the remaining 50% ( ) will discharge s through the other incoming conductive services such as metallic water and gas pipes electric power supply etc The percentage of the current that will flow through each incoming conductive service (I ) can be i calculated I i = I s / n where n is the total number of the incoming conductive services s an example if a structure has three (n = ) conductive incoming services (one metallic water pipe one metallic gas pipe and one power cable) then in the event of a direct lightning strike on the structure the local earthing system will discharge the 50% of the lightning current and the remaining current will be subdivided to the three conductive incoming services I = I / => I = 166% (see Figure 4) i s i In case that one incoming conductive service has more that one conductive lines (ie an incoming phase power cable may have four conductors and ) than the calculation of the distribution of 1 2 the lightning current that will flow through each of the conductive lines ( ) is given by the division of the percentage of the lightning current v that will flow through conductive service (I ) with respect to the i number of the conductive lines of the cable (m) v= I i/ m For example if a structure has only one incoming conductive power cable (n = 1) which is composed out of four (m = 4) conductors ( 1 2 and ) then in the event of a direct lightning strike on the structure the local earthing system will discharge the 50% of the lightning current and the reaming 50% will flow through the power cable Then each conductor of the power cable will discharge the 125% of the total lightning current I = I / 1 (n = 1) => I = 50% and = I / 4 (m = 4) => i s i v i = 125% (see Figure 5) v Direct lightning strike 100% Electrical power network 100% of the lightning current will flow through the down conductors 166% 166% of the current will flow through the electrical power network Metallic buried pipe Gas 166% 50% 50% of current to local earthing 166% of the current will flow through each pipe network Metallic buried pipe Water 4 Figure 4 ightning current distribution to the incoming conductive lines of a structure 7

9 U p = <19kV I imp = 25k (10/50 s) I max = 200k (8/20 s) U p = <19kV I imp = 25k (10/50 s) I max = 200k (8/20 s) U p = <19kV I imp = 25k (10/50 s) I max = 200k (8/20 s) U C = 255Vac U p = <4kV I imp = 100k (10/50 s) Imax = 200k (8/20 s) T a = <100ns T1 + T2 CE еб еб SURGE PROTECTIVE DEVICES 4 X 25k (10/50 ) 1 / Substation earthing 2 PE 200k (10/50 s) 100k (10/50 s) PE 100k (10/50 s) ocal earthing k (10/50s) Figure 5 ightning current distribution to the electric power conductors maximum lightning current as per E is considered 200k (10/50s) / (ightning Protection Zones PZ) PZ PZ 0 PZ 0B PZ 1 PZ 2Ад Internal ightning Protection System PS The aim of the internal PS is to protect human life and electrical / electronic installations against surge overvoltages which are caused either by direct or indirect lightning strike s described in the European and International standard E / IEC the volume of the structure that is to be protected against lightning shall be divided into zones (ightning Protection Zones PZ) with respect to reduction of the electromagnetic effect of the lightning current and on the dielectric strength of the under protection equipment The basic PZ are the following PZ 0 Equipment installed in this zone will be subjected to full direct lightning current and electromagnetic effects without any reduction measure PZ 0B Equipment installed in this zone will not be subjected to direct lightning current but they will be subjected to full electromagnetic effects without any reduction measure PZ 1 Equipment installed in this zone will be subjected to partial lightning current and high electromagnetic effects at a reduced level than upstream zones PZ 2Адn Equipment in this zone will be subjected to surge currents and low electromagnetic effects depending on the protection measures that have been taken in upstream zones ll equipments that are installed in the same zone should be at the same potential This can be succeeded by applying equipotential bonding to all conductive parts including the reinforcement of the structure where this is possible to be achieved with respect to earth either by a direct bonding or through a surge protective device 8

10 еб еб SURGE PROTECTIVE DEVICES 0 10/50s Zone 0 Subjected to direct lightning strike 10/50s /50s Zone 1 ightning currents 10/50s 2 8/20s Zone 2 Surge currents 8/20s Zone 0 Zone 0 Zone 0 Protected from direct lightning strike MX Immunity of equipment to the electromagnetic field inside the structure due to lightning MI 6 (PZ) Figure 6 ightning protection zones (PZ) according to E / IEC IEC / 400V C 8 20 / 400V C V Overvoltage categories ccording to the international standard IEC all electrical equipment are divided into overvoltage categories which depend on the nominal operating voltage of the equipment and on the installation point of the equipment Figure 7 shows the four basic overvoltage categories of equipment that are installed in a 20/400V C system The selection of the surge protective device shall be based on the fact that its voltage protection level must be lower than the dielectric strength of the under protection equipment In Figure 8 is presented the equivalent surge protective device for the protection of each of the previous four categories dditionally for the final selection of the surge protective device it must also be considered the lightning or surge current discharge capability of it Category V equipment Devices used in electrical installation such as switchboard equipment fuses cables meters etc Category II equipment Devices permanently connected to an electric installation such as motors generators water pumps and generally industrial type equipment Category I equipment Devices and electrical appliances connected to the electrical installation mainly used for domestic applications which do not contain electronic circuits Category equipment Devices connected to the electrical installation contain sensitive electronic circuits 9

11 U =275Vac U =275Vac U =275Vac C C C? n =15?? (8/ 20s)? n =15?? (8/20s)? n = 15?? (8/20 s)?max=40?? (8/ 20s)?max= 40?? (8/20s)?max= 40?? (8/20s) U p = <19kV U p = <19kV U p = <19kV T = <25ns T = <25ns T = <25ns a a a UC=255Vac? =20?? (8/20 s) n?max=40?? (8/20 s) U p = <12kV T = <100ns a еб еб SURGE PROTECTIVE DEVICES 6kV IV Category IV 4kV III Category III 25kV 15kV II Category II I Category I 7 20/400V C IEC Figure 7 Overvoltage categories of electrical equipment installed in a 20/400V C system according to IEC kV 6kV 25kV 15kV CT III CT I MV CT IV CT II PE U C = 255Vac U p = <19kV U p = <19kV U p = <19kV U p = <4kV I imp = 25k (10/50s) I imp = 25k (10/50 s) I imp = 25k (10/50s) I imp = 100k (10/50s) Imax= 200k (8/20s) Imax = 200k (8/20s) Imax = 200k (8/20s) Imax = 200k (8/20 s) T a = <100ns T1 + T2 CE T2 CE T2 CE T2 CE T2 CE 40T2 40T2 40T2 40GT2 PE MV rrester T1 s T2 s T s 8 IV Figure 8 Categories of surge protective devices used to protect equipment of overvoltage category IV up to I 10

12 / Current (k) еб еб SURGE PROTECTIVE DEVICES Type 1 (T1) Class I I (10/50s) imp 2 ype 2 (T2) Class II I max (8/20s) ype (T) Class II I (8/20s) U (12/50s) oc 1 ( ) PZ 0 PZ 1 PZ 0 PZ 1 (10/50s) (U ) p 4kV III IV ( 8) 2 ( ) PZ 1 PZ 2 (8/20s) (U p) 25kV II ( 8) ( PC ) (8/20s) (U p) 15kV I 2 ( 8) /50s 2 8/20s H 9 sc Categories of power surge protective devices ccording to the standard E the surge protective devices which are connected to a low voltage system are separated into three categories st 1 Type 1 (T1) Class I primary protection against lightning current I (10/50s) imp nd 2 ype 2 (T2) Class II secondary protection against surge current I max (8/20s) rd ype (T) Class II fine protection against surge currents I (8/20s) and surge overvoltages U (12/50s) oc T1 surge protective devices are mainly installed at the entry point of the electrical installation into a structure (ie main switchboard) at the borders between PZ 0 PZ 1 or PZ 0 PZ 1 providing protection against lightning currents (10/50s) having a voltage protection level (U ) lower than 4kV protecting equipment of p overvoltage category III and IV (see Figure 8) T2 surge protective devices are installed at main node points of the electrical installation (ie secondary switchboards) at the borders between PZ 1 PZ 2 providing protection against surge currents (8/20s) having a voltage protection (U p) level lower than 25kV protecting equipment of overvoltage category II (see Figure 8) T surge protective devices are installed independently of the zone boundaries Their installation point is as near as possible to the under protection equipment which contains electronic circuits (ie PC PC etc) providing fine protection against both surge currents (8/20s) and surge voltages having a voltage protection level (U p) lower than 15kV protecting equipment of overvoltage category I T surge protective devices should always be installed at least after at least T2 surge protector (see Figure 8) The basic difference between the T1 T2 and T s is that T1 s are capable to discharge lightning currents of a waveshape 10/50s instead T2 and T are only able to discharge surge currents of a waveshape of 8/20s The main difference between the two waveshapes is illustrated in Figure 9 sc k 10/50s 25k 8/20s 10/50s T1 25k (10/50s) times more powerful T2 40k (8/20s) /20s 0 250s 500s 750s 1000s 1250s 1500s / Time (s) 9 10/50s 8/20s Figure 9 Differences between lightning current waveshape 10/50s and surge current waveshape 8/20s 11

13 еб еб SURGE PROTECTIVE DEVICES ( 10) ( ) ( 10) ( 10C) Selection of power surge protective devices The selection and the necessity of installing surge protective devices arrives after performing the risk management according to the standard E / IEC Due to the careful and detailed study that it is required the following examples just give an indication of the necessary surge protective devices as well as their installation point Case Structure having an external lightning protection system installed st nd Requires 1 installation of T1 s at the main distribution board 2 rd installation of T2 s at secondary distribution boards and installation of s at the entrance of equipment containing electronic circuits (see Figure 10) Case B Structure not having an external lightning protection system installed but having incoming conductive services (ie overhead electric or telecom lines) exposed to direct lightning strike st nd Requires 1 installation of T1 s at the main distribution board 2 rd installation of T2 s at secondary distribution boards and installation of s at the entrance of equipment containing electronic circuits (see Figure 10B) Case C Structure neither having an external lightning protection system installed or incoming conductive services (ie overhead electric or telecom lines) exposed to direct lightning strike st nd Requires 1 installation of T2 s at the main distribution board 2 installation of s at the entrance of equipment containing electronic circuits (see Figure10C) In all the above case studies coordination between the surge protective devices should be considered 1 2 Structure with external PS If fine protection is required Structure withut external PS but with overhead supply If fine protection is required 1 T1 s are not required Structure with underground supply or without external PS If fine protection is required 10 Figure 10 Selection and installation of power surge protective devices 12

14 еб еб SURGE PROTECTIVE DEVICES 10m m m (H/Y & /) 20m 10m Installation points of power surge protective devices The installation of surge protective devices depends on the electrical installation of the structure as well as on the under protection equipment Due to the careful and detailed study that it is required the following examples just give an indication of the necessary surge protective devices as well as their installation point Case structure that contains an electrical installation which the total cabling length does not exceed 10m Then by installing all the three types of s T1 + T2 + T in the main distribution panel considering an appropriate coordination between them then no additional protection is needed Case B structure that contains an electrical installation which the total cabling length does not exceed 20m Then by installing T1 + T2 s in the main distribution panel and additional T s in the secondary distribution panel assuming that the cabling distances between the secondary panel and the electronic equipment does not exceed 10m in length then no additional protection is needed Case C structure that contains an electrical installation which the total cabling length does exceed 20m assuming that the cabling distances between the secondary panel and the electronic equipment does not exceed 10m in length then by installing T1 + T2 s in the main distribution panel and additional T2 + T s in the secondary distribution panel no additional protection is needed Case D structure that contains an electrical installation which the total cabling length does exceed 20m assuming that the cabling distances between the secondary panel and the electronic equipment in B 1

15 еб еб SURGE PROTECTIVE DEVICES 20m 10m m some cases does exceed 10m in length then by installing T1 + T2 s in the main distribution panel T2 + T s in the secondary distribution panel and additional T s in selective electronic equipment for which the cable length up to the secondary panel does exceed the 10m Case E Ideal protection scheme independent of the cabling distances in the main distribution panel T1 + T2 s in the secondary distribution panel T2 s and T s next to each electronic equipment C D E 14

16 еб еб SURGE PROTECTIVE DEVICES o (PST ISD DS) (Hz) (V) () (Hz) (W) ( BC ) (50 75 ) Selection of data surge protective devices The selection of data surge protective devices depends on the signal that the is connected through In brief the selection criteria are Telecom signals Type of telecom line (PST ISD DS) nalogue and digital signals Frequency of the signal (Hz) voltage (V) and current () of the signal High frequency RF signals Frequency of the signal (Hz) power of the signal (W) connector type ( BC etc) surge impedance of the cable (50 75 etc) / Output (EQUIP) / Input (IE) PC Short Distance E2 E E1 EQUIP DT SURGE PROTECTOR GD IE 1 2 Cable Shield PE U C =275Vac U C =255Vac I n =5k (8/20s) I n =10k (8/20s) I max =10k (8/20s) I max =20k (8/20s) U p = <15kV U p = <1kV T a = <100ns Surge protection of information technology systems T CE T CE 10T 20GT PC Fine surge protection of PC 11 Figure 11 Selection and installation of data surge protective devices Selection of connection conductor diameter of low voltage power surge protective devices according to E / type 1 2 () mm 6 mm 15 mm Minimum cross section of conductor (copper) 1 () mm 5 mm 5mm Maximum cross section of conductor1 (copper) 1 DI 1 For EEMKO s to be installed on DI Rail HD 84 The selection of the fuse shall satisfy the requirements for the as well as for the connection conductor according to installation rules of the country that the will be installed 15

17 U p = <19kV I imp = 25k (10/50s) I max = 200k (8/20s) U p = <19kV I imp = 25k (10/50s) I max = 200k (8/20s) U p = <19kV I imp = 25k (10/50s) I max = 200k (8/20s) U p = <19kV I imp = 25k (10/50s) I max = 200k (8/20s) U p = <19kV I imp = 25k (10/50 s) I max = 200k (8/20s) U p = <19kV I imp = 25k (10/50 s) I max = 200k (8/20s) U C = 255Vac U p = <4kV I imp = 100k (10/50s) Imax = 200k (8/20s) = <100ns T1 + T2 CE U C = 255Vac U p = <4kV I imp = 100k (10/50s) Imax = 200k (8/20s) = <100ns T1 + T2 CE BSIC ISTTIO ISTRUCTIO OF S ength and path of s earthing conductor The installation of the power s in the distribution panel shall be performed with short connection wires ccording to E the appropriate connection wires shall not exceed the 05m in length arge loops especially by the PE conductor shall be avoided dditionally the impression that the earthing conductor of the s shall be completely independent from the PE conductor or the equipotential bonding bar of the panel is completely wrong To oads RCD 8899kWhr PE T a 12 Figure 12 Installation of power s in the distribution panel by using the minimum required connection wire and having common bonding bar between the PE conductor and the earthing conductor of the s CORRECT To oads RCD 8899kWhr PE T a 1 Figure 1 Installation of power s in the distribution panel by using long connection wire and independent from the PE conductor WROG 16

18 SURGE PROTECTIO rrester is operational when green light is on SURGE PROTECTIO rrester is operational when green light is on SURGE PROTECTIO rrester is operational when green light is on SURGE PROTECTIO rrester is operational when green light is on BSIC ISTTIO ISTRUCTIO OF S 6205 / Common earthing system ccording to the E 6205 from the lightning and surge protection point of view a common and single integrated earthing system is preferable and is suitable for all purposes (ie safety earthing lightning protection earthing telecommunication earthing)??? 8899kWhr OTE 14 Figure 14 Common earthing system CORRECT??? 8899kWhr OTE 15 Figure 15 Independent earthing systems WROG 17

19 SURGE PROTECTIO rrester is operational when green light is on SURGE PROTECTIO rrester is operational when green light is on BSIC ISTTIO ISTRUCTIO OF S ( ) (05m ) Distance between and under protection equipment ccording to E the efficiency of a surge protective device is also relevant to the distance between the and the under protection equipment s a maximum distance the standard defines the 10m For a distance longer than 10m then an additional shall be installed The ideal distance is up to 05m 05m 16 <10m (05m ) Figure 16 Distance between and under protection equipment < 10m (05m ideal) CORRECT >10m 17 > 10m Figure 17 Distance between and under protection equipment > 10m WROG 18

20 U p = <19kV I imp = 25k (10/50s) I max = 200k (8/20s) U p = <19kV I imp = 25k (10/50s) I max = 200k (8/20s) U p = <19kV I imp = 25k (10/50 s) I max = 200k (8/20s) U C = 255Vac U p = <4kV I imp = 100k (10/50s) Imax = 200k (8/20s) T a = <100ns T1 + T2 CE U p = <19kV I imp = 25k (10/50s) I max = 200k (8/20s) U p = <19kV I imp = 25k (10/50s) I max = 200k (8/20s) U p = <19kV I imp = 25k (10/50 s) I max = 200k (8/20s) U C = 255Vac U p = <4kV I imp = 100k (10/50s) Imax = 200k (8/20s) T a = <100ns T1 + T2 CE U p = <19kV I imp = 25k (10/50s) I max = 200k (8/20s) U p = <19kV I imp = 25k (10/50s) I max = 200k (8/20s) U p = <19kV I imp = 25k (10/50 s) I max = 200k (8/20s) U C = 255Vac U p = <4kV I imp = 100k (10/50s) Imax = 200k (8/20s) T a = <100ns T1 + T2 CE BSIC ISTTIO ISTRUCTIO OF S HD 84 ( ) ( ) Selection of overcurrent protection of s The use of an overcurrent protection device for the protection of the end of life of the as well as for the connection wire is a requirement even by the installation rules However the overcurrent protection device may limit the efficiency of the since it should behave in an appropriate manner when discharging surge currents The best overcurrent device with respect to surge current discharge capability is the cartridge type fuse since it is constructed by a single wide wire element of rather short length In contrast the MCBs and the RCDs contain internal coils with rather long and thin wires and therefore the surge discharge current capability is limited Especially the RCD which is used for protection against electric shock the internal circuitry is of vital importance and it should not be damaged Therefore in countries where the use of s (at least for the primary protection in the main distribution panel) before the RCD is allowed by the installation rules may be a good practice Of course the use of MCBs or RCDs as overcurrent protection can not be claimed to be wrong however where this is allowed by the national electrical installation rules s are advised to be installed before any MCB or RCD To oads RCD PE 18 Figure 18 Use of cartridge type fuses as an overcurrent protection of the s in the main panel CORRECT To oads To oads RCD PE PE RCD 19 Figure 19 Use of MCB or RCD as an overcurrent protection of the s in the main panel OT DVISED 19