V1.0- 9.01.2015 Page 1 of 68 Preface, Our long experience enables us to offer our customers integrated high-tech devices, from in- house development, manufactured in recognised industrial conditions and reaching the top quality for installers and end users. With standalone and modular concepts we are able to offer maximum flexibility for field applications. These innovative products are developed and manufactured to the highest level achieving an excellent level of quality. The following guide lines which include real world examples as illustrations aim to benefit planners, installers and commissioning engineers, the theme is to provide an approach to diagnostics and troubleshooting of devices housed within and around a technical cabinet. Modern devices are based on advanced electronics technologies, with this the accuracy is higher and the measurement faster than in previous generations. This greater precision and accuracy requires an environment with the same attention to detail. In the field more often these devices are mounted together with Frequency Converters (FC), Power switched mode power supply elements, commonly used for better and more accurate pumps management and ventilation systems, however due to the way these devices function they can affect other devices by propagating Electromagnetic distortion waves or electromagnetic interference (EMI) which disturbs many electronic systems, irrespective of the colour of the box or the label or mark stamped on the bottom. This booklet is the fruit of the collected experience over recent years from many staff. It is the result of knowledge exchanged and transferred, applied and implemented, we hope it will bring support for field engineers, planners, programmers, project managers, technicians and all people getting in touch with this area. It is not the intention that this document will replace local laws, standards, product data sheet, product information, mounting instructions and any other official document issued by this or any other manufacturer. Special thanks to all NSO people who contributed and helped in the discourse, knowledge and experience transfer in order to give us the possibility to write this technical documentation Through this guide you will find practical help, grounding will be highlighted, EMC will be explained and you will be armed in how to identify and overcome grounding and EMI issues. SAUTER Technical Support V1.0- 9.01.2015 Page 2 of 68 V1.0- 9.01.2015 Page 3 of 68 Table of Contents 1. Grounding (Fundamentals) ......................................................................................................... 8 1.1. Grounding (equipotential relations) ................................................................................. 9 1.2. Grounding resistance ......................................................................................................... 9 1.3. Grounding and its position in electrical theory. ............................................................ 10 1.4. Grounding connections .................................................................................................... 10 1.5. Grounding in Buildings .................................................................................................... 11 1.6. Grounding and transformers or DC Power supply ...................................................... 11 1.7. Power supply ..................................................................................................................... 12 2. ESD - EMI – EMC- Transients .................................................................................................. 14 2.1. ESD .................................................................................................................................... 14 2.2. EMI ...................................................................................................................................... 16 2.3. EMC .................................................................................................................................... 18 2.4. Transients (or fast transients) ......................................................................................... 20 3. The electrical cabinet ................................................................................................................. 22 3.1. General purpose ............................................................................................................... 22 3.2. Cabinet structure .............................................................................................................. 25 3.3. Grounding in cabinets ...................................................................................................... 27 3.4. Cabinets and projects ...................................................................................................... 31 3.5. Cabinet setup (According section 3.2.2) ....................................................................... 32 4. Diagnostics .................................................................................................................................. 34 4.1. Step by step methodology .............................................................................................. 35 4.2. Technical diagnostic ........................................................................................................ 38 4.3. Commissioning ................................................................................................................. 39 5. Real world examples of grounding issues .............................................................................. 40 5.1. Freezing of a modular based PLC system. .................................................................. 40 5.2. Pending PLC inputs ......................................................................................................... 42 5.3. Conclusion ......................................................................................................................... 46 6. Grounding First Aid Guidance .................................................................................................. 48 6.1. EMC / EMI in the field ...................................................................................................... 48 6.2. Tips and tricks ................................................................................................................... 51 6.3. Cabling. .............................................................................................................................. 53 6.4. Main ground ...................................................................................................................... 53 6.5. Shielding issues ................................................................................................................ 54 7. Checklist for grounding .............................................................................................................. 56 7.1. Grounding (See chapter 1) ............................................................................................. 56 7.2. Shielding (see section 3.3) .............................................................................................. 56 7.3. Cabinet (see section 3) .................................................................................................... 56 7.4. Cabling (see section 3.2 end 3.3) .................................................................................. 56 7.5. Mandatory (see section 3.4) ........................................................................................... 56 8. With reference to SAUTER products ....................................................................................... 58 8.1. SAUTER technical standardisation ............................................................................... 58 8.2. Modulo 5 ............................................................................................................................ 58 8.3. Tips and tricks ................................................................................................................... 62 Personal notes ........................................................................................................................................ 64 Resume .................................................................................................................................................... 66 V1.0- 9.01.2015 Page 4 of 68 V1.0- 9.01.2015 Page 5 of 68 Symbols and definitions used in this document Danger Forbidden Recommended – Approved good practice Caution Abbreviations N Neutral L Live Ph Phase PE Protected Earth PEN Protected Neutral Earth (TNC mode) (-) Negative pole (+) Positive pole ESD Electrostatic discharge EMI Electromagnetic interference TT Earth/Neutral regime according TT schema TN Earth/Neutral regime according TN schema IT Earth/Neutral regime according IT schema AC Alternative Current DC Direct current NB: Nota Bene GFCI Ground Fault circuit interrupter FC Frequency converter PCB printed circuit board UPS Uninterruptible Power Supply HMI human–machine interface BMS Building management system PPE Personal protective equipment PDS Product data sheet FI Fitting instruction EMF Electromagnetic field PI Product information CCC China Compulsion Certification Note: Images and figures contained in this document are for illustration purposes only. V1.0- 9.01.2015 Page 6 of 68 V1.0- 9.01.2015 Page 7 of 68 1. Grounding