EMC of systems and installations

Goals

The objectives of the training EMC of systems and installations :

Take into account all key EMC parameters when wiring and implementing an industrial system.

The aim of this training course is to:

• Learn how to identify EMC risks for a system or installation


• Be able to identify the main sources of interference


• Know how to recognise and understand the coupling mechanisms involved


• Master the appropriate protection methods and their industrial implementation


• Know how to adopt an approach to solving EMC problems

Program

1 - Introduction
• EMC of an industrial system
• Definitions/units
• Developments in electronics
• Envelope detection
• Time/frequency reciprocity


2 - Conducted disturbances
• Differential mode disturbances
• Common mode disturbances
• Conductor impedance
• Common impedance
• Equipotentiality of masses
• Mesh impedance
• Board-to-chassis coupling
• Crosstalk


3 - Radiated disturbances
• What is an EM field?
• Electric/magnetic field
• Field propagation and reflection
• Effect of EM fields on electrical conductors
• Critical frequencies, orders of magnitude


4- Human risks
• Risk of electrocution
• Recommendation 1999/519/EC
• Directive 2013/35/EU
• Exposure levels


5 - Sources of interference
• Field radiated by a radio transmitter
• High-frequency industrial equipment
• Electrostatic discharges
• Characteristics of lightning strikes
• Causes and effects of lightning
• Overvoltages when coils open
• Sources of 50 Hz magnetic fields
• Rectifier bridges
• Switching power supplies
• Variable speed drives


6 - Power supply
• Power supply network quality
• Impact of neutral systems on EMC
• TT system
• TN-C and TN-S systems
• IT system


7 - Earth
• Roles of earth, neutral and PE
• Are multiple earths required?
• Earth resistance measurements
• Setting up an earth network
• Protecting a building against lightning
• Connecting a lightning conductor to earth


8 - Earth networks
• Regulations and earthing
• Star earths and earth loops
• Effect of earth loops
• Mesh earth network
• Earthing of equipment
• Island cabling: cabinets, technical rooms
• Grounding connections


9 - Interconnection cables
• Principle of the reducing effect
• Cable shielding
• Where to connect the shields?
• New best practices
• Implementation of connectors
• Symmetrical connections
• Low-level connections
• Digital connections
• Galvanic isolation
• Isolation transformers
• Cable trays and conductive structures
• Implementation of cable trays
• Cable classification, cabling rules
• Specific cases


10 - Protection and filtering
• Surge arresters
• Spark gaps / surge arresters / limiters
• Installation of surge arresters
• Choice and installation of a mains filter
• Isolation transformer
• Role of ferrites
• Choice and implementation of ferrites


11 - Screens and shielding
• Role and operation of shielding
• Shielding leaks
• Treatment of openings
• Conductive joints, contacts, continuity
• Examples of magnetic screens
• Practical solutions


12 - Installation
• Choosing EMC solutions
• Structure meshing
• Conductor penetrations
• Protection coordination
• Copper or fibre optic connections?


13 - Validation
• How to assess a system's immunity?
• Checking ground connections
• On-site immunity testing
• Choosing a test generator
• Immunity to fast transient bursts
• Immunity to walkie-talkies


14 - Remedies<
• EMC faults: what to do?
• On-site diagnostics and analysis
• Correction method
• Specific instrumentation
• Use of HF current clamp
• Use of Moebius probe
• Orders of magnitude, examples of remedies
• Practical case