De allereerste foto van licht als golf én als deeltje (bron: engineersonline.nl ) De foto van licht dat is ingesloten op een nanodraad toont

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2 De allereerste foto van licht als golf én als deeltje (bron: engineersonline.nl ) De foto van licht dat is ingesloten op een nanodraad toont tegelijkertijd ruimtelijke interferentie en energiekwantisering (foto: Fabrizio Carbone/EPFL). 2

3 Integrated Earth Systems THE basis for Critical Systems Presented at March 5, 2015 by Rob Kersten 2015 MIW Consultants - 3

4 Overview Introduction Safety First! Earthing (grounding) history: - Electrical power distribution systems - Earthing - Safety and EMC - Lightning protection, safety and EMC Conclusions Questions 2015 MIW Consultants - 4

5 Introduction My first job was with NCR as site engineer for the first computer systems at the DNB, RPS etc. The next challenge was found with Foxboro (today Schneider Electric) in Industrial Automation. Via service, hardware system and network design, I became their global consultant - Mr. Power & Grounding We ve established MIW Consultants in 2008 See for further details Board member Dutch EMC-ESD Society 2015 MIW Consultants - 5

6 Safety First! 50 Vac 110 Vdc Safe Voltage Area? This is NOT a Safe Voltage Area in a humid-, medical- or explosive- (ATEX) environment etc MIW Consultants - 6

7 Risk Management Safety & security of (electronic) systems, is essential for all organizations, Organizations can be put in a very vulnerable position when their processes are interrupted, Proper earthing is one of the elements, fundamental for the stability of critical (electronic) systems MIW Consultants - 7

8 Earthing (Grounding) Earth connections are required for: - Protective earth (PE) = Safety - Functional earth (FE) = Security & Reliability (EMC, shielding, electronic reference) - Lightning protection = Safety & Security & Reliability - ESD = Reliability thus also Safety & Security - Etc. Design-, installation- and maintenance- engineers must master ALL these disciplines (too often different companies with different engineers and different agenda s)! 2015 MIW Consultants - 8

9 Energy Distribution Networks The various earthing concepts of energy distribution networks are defined in IEC 60364: IT The power source is floating (not earthed). Metal enclosures and structures are locally earthed with a PE conductor. TN-S The neutral is earthed at the energy source. Metal enclosures and structures are earthed with a PE conductor between energy source and connected loads. TN-CS The neutral is earthed at the energy source. Metal enclosures and structures are earthed with a combined Neutral and PE conductor between energy source and connected loads. TT The neutral is earthed at the energy source. Metal enclosures and structures are locally earthed. NOTE 1: Each energy distribution network provides safety when correctly designed, installed and maintained Note 2: Other characteristics differ considerably (i.e. EMC) MIW Consultants - 9

10 TN-S Energy Distribution Networks The TN-S energy distribution network has the best EMC characteristics for industry. The intended current flows entirely through the line (L) en neutral (N) conductors. The primary function of the protective earth conductor (PE) is safety, but is also an efficient (low impedance) return path for interference currents from line filters and surge protective devices, without the disadvantages of the TN-CS network. L N PE NE 98 First price for EMC in INDUSTRY! E Re U = U 2 (Identical conductors) 4. Network types (TN and IT nets) TN and IT nets are usual today for three-phase systems in installations where low power supply is involved. Differing consequences are involved for recommended EMC measures, depending on the network type utilized. TN-S nets are more practical from an EMC perspective and therefore preferable MIW Consultants - 10

11 Typical classical Island System Protective Earth (PE) Utility Power Ultra Isolation Transformer HF Choke HF Choke 20 µh 1.5 mohm 25 mm² Ep Es Np Ns Lp Ls Ultra Isolation Transformer Safety Earth Dedicated Earth Dedicated Power Run Dedicated Earth- and Signal cables in close proximity Functional Earth Comm. Electronics Processor Electronics Isolated I/O Electronics Fenced Island Soil (Earth) Surface PE Earth Rod(s) Impedance < Dedicated Earth Isolated & Shielded below PE and at least 4 m below surface. Feeder n Feeder 2 Feeder 1 N L E N L E N L E Clean Earth Minimum distance equals length of longest rod Dedicated Earth Rod(s) Impedance < 2 Ohm OUTDATED! Not for new designs! 2015 MIW Consultants - 11

12 The Result : Chaos on EARTH! Earth Mother Earth Clean Earth Dirty Earth Computer Earth Plant Earth Instrument Earth Separate Earth Structural Earth Power Earth Analog Earth Digital Earth Safety Earth Ground 2015 MIW Consultants - 12

13 THE Solution: Regulations & Directives CISPR 1933 Radio Frequency Interference (RFI) USA - FCC since 1979 Radiation only EU - EMC Directive since 1989 Radiation & susceptibility EU - CE mandatory for EMC since EMC Reliability Safety Security! 2015 MIW Consultants - 13

14 Eenvoudig veldsterkte proefje > 6,5 V/m 1 meter 2015 MIW Consultants - 14

15 THE Solution: Think EMC!!! DC 400 GHz +++ EMC = Electro-Magnetic Compatibility (don t disturb / be disturbed) EMI = Electro-Magnetic Interference EMS = Electro-Magenetic Sensitivity ESD = Electro-Static Discharges Today you need: SAFETY NEN 1010 Lightning protection NEN Explosion Protection ATEX Electro Magnetic Fields ICNIRP Power Quality EN Medical Equipment NEN MIW Consultants - 15

16 CE wordt slecht begrepen in buitenland, (helaas ook vaak slecht in Europa!) 2015 MIW Consultants - 16

17 Solution: Safety and EMC IEC/TR (1997) Clear guideline for installations : How (not) to earth How to obtain optimal EMC behavior WRONG WRONG GOOD!!! 2015 MIW Consultants - 17

18 Solution: Safety and EMC IEC/TR (1997) 2015 MIW Consultants - 18

19 Solution: Safety and EMC IEC/TR Why are all these interconnections so important? They provide Safety (reduced step and touch voltages) They reduce the impact of lighting hits = Security They reduce EMC problems caused by normal and common mode interference = Reliability See also White Paper ECI Publication No Cu MIW Consultants - 19

20 Solution: Lightning Protection, Safety & EMC conform IEC (2006) IEC (LEMP) introduced an even further integrated approach for earthing of an entire complex! Lightning earth grids: Inside building: 5 x 5 m Around building: 20 x 20 m Open area: 40 x 40 m 20

21 Question: Is it still important to prevent earth loops? That differs from case to case! Rarely within a PE network Sometimes for a cable shield (i.e. when shield = return conductor) Often within the FE network (signal path) Almost always in medical environments! There is NO black & white answer! Earth Systems Must Be Designed By Engineers! 2015 MIW Consultants - 21

22 Earth Demo Earth Loop via Coax Shield Conductor Intended Signal + 50 Hz Earth Loop Intended Signal 1000 Hz 2015 MIW Consultants - 22

23 Conclusions Dedicated earth systems operated reasonably well until the 1980 s. EMC understanding was still improving & system clock speed is ever increasing Today we generally need the Integrated Earth System for safety earth, functional earth and lightning protection! The Integrated Earth System is a robust and field proven technology for Safety and Security Remaining dedicated earth systems must be exclusively maintained / upgraded by specialists, medical system too! 2015 MIW Consultants - 23

24 Questions? Integrated Earth Systems? Safety? Security? Availability? Electronic Systems? Critical Systems? 2015 MIW Consultants - 24

25 Thank you, for your attention! 2015 MIW Consultants - 25

26 Disclaimer The author disclaims liability for any direct, indirect, consequential or incidental damages that may result from the use of the information, or from the inability to use the information or data contained within this presentation. Any terms mentioned in this document that are also registered trademark have not been clearly marked. Therefore, it cannot be concluded from an absent or marking that a term is an unregistered trademark. Equally, it cannot be determined from the text if patens or protection of utility patents apply. Copy Rights The author expresses his thanks to the International Electrotechnical Commission (IEC) for permission to reproduce Information from its International Publication IEC (1997) and IEC (2006). All such extracts are copyright of IEC, Geneva, Switzerland. All rights reserved. Further information on the IEC is available from IEC has no responsibility for the placement and context in which the extracts and contents are reproduced by the author, nor is IEC in any way responsible for the other content or accuracy therein. Citations from other origins are included under the applicable citation rights (i.e. the USA fair uses policy ). They underline the importance of the discussed Integrated Earth System. The author expresses his sincere thanks to their owners MIW Consultants - 26