Source: European Union EMC Directive

Critical European Immunity Standards

• IEC 61000-4-2 ESD         
• IEC 61000-4-4 EFT         
• IEC 61000-4-5 Surge         
• IEC 61000-4-8 Power Frequency Magnetic Field         
• IEC 61000-4-11 Dips and Interrupts
  

Critical European Emissions Standards

• IEC 61000-3-2   
• EIC 61000-3-3    
   

The enactment of the EMC Directive in January of 1996 precipitated a global initiative to harmonize compliance regulations.
For manufacturers of electronic and electrical products, these directives and regulations have had and will continue to have an enormous impact upon how business is conducted worldwide. Acceptable routes for bringing products affected by the Directive to the marketplace are well defined. Manufacturers who do not adhere to EMC test protocols face the prospect of at a minimum a financial fine and at the extreme losing entire markets

The EMI (Electromagnetic Interference) Phenomena

There are five basic types of EMI-related phenomena that the majority of electrical and electronic products must be
tested to:

• Electrostatic Discharge (ESD) charged people or objects that disrupt the operation of or cause damage to electrical or electronic equipment by either making direct contact or within close proximity to cause damage.

• Electrical Fast Transient (EFT) switching transients coupled into power or I/O lines that may disrupt the operation of or cause damage to electrical or electronic equipment usually as a result of mains power switches from the power stations or within the building.

• Surge nearby lightning strikes that couple relatively high energy transients into power lines that may disrupt the operation of or cause damage to electrical or electronic equipment.

• RF Fields (Radio Frequency) resulting from either intentional radiators, such as TV/broadcast stations or mobile radios, or unintentional radiators, such as other electronic equipment that may disrupt the operation of or cause damage to electrical or electronic equipment.

• Power Quality dips and interrupts of the mains which are the result of faults in the power distribution system such as a low mains voltage condition caused by an overload at the power station or an open circuit breaker that may cause damage to electrical or electronic equipment.

Products that display a reasonable degree of immunity to these events will generally prove reliable in the field.

• Harmonic  currents are generated by many of the power supplies used in
  modern electronic equipment.  The European Union believes that these
  harmonics could be additive, causing significant problems in the power
  distribution grid.
  
  
• Flicker  is a measure of annoyance to humans caused by lighting "flicker"
  resulting from voltage fluctuations caused by electrical and electronic
  products.

Products that display a reasonable degree of immunity to these events will generally prove reliable in the field.

Testing and Equipment Requirements

In general, compliance to international immunity regulations can be achieved at lower test levels than required by industry or customer-driven standards. In all cases, test methods must be accurate and repeatable.

For the majority of products, manufacturers can perform in-house testing using an inexpensive immunity tester to conduct the necessary compliance tests for EMC immunity standards.

Compliance is not a static process: continued legislation and technological changes ensure that test protocols and standards will continue to evolve. Companies with a well-defined EMC test plan which anticipates future regulations,
will be in the best position to successfully compete in the global marketplace.

The Routes to Compliance

There are three basic routes to compliance.

1. Declaration of Conformity (also called Manufacturer's Declaration)

   This is the route preferred by the EMC Directive, as well as most manufacturers because it allows them complete control over the testing process. Tests are either performed in-house or at an outside test facility in accordance with the relevant standards. Upon successful completion of testing and documentation of the results, the manufacturer issues a Declaration of Conformity and affixes the CE Mark to the product. The Declaration of Conformity is filed at the manufacturer's agent/representative in the European Union (EU).

2. Technical Construction File (TCF)

   The Technical Construction file is used when tests can not be performed in accordance with relevant standards. This approach is used when standard test procedures are not possible or when alternative test standards and/or methods are used because of the product's constraints. The TCF describes the apparatus in detail, sets of procedures used to insure conformity to the intent of the EMC Directive and includes a technical report or certificate from a Competent Body (currently only European test facilities or subsidiaries designated by member states to have authority). The declaration and marketing process is identical to that for a Declaration of Conformity.

3. Type Acceptance

This compliance process is for products designed for the transmission of radio communications as defined by the ITU (International Telecommunications Union). The manufacturer, or its authorized representative in the EU, must obtain an EU type examination certificate from a Notified Body (a Notified Body is designated by the government - typically one or two per country). The declaration and marking process is identical to that for a Declaration of Conformity.