Contents

• Understanding the EN5022 Tangle
• Significance of the date of cessation of conformity for amendments to CENELEC harmonised EMC standards
• EN 55022 and presumption of conformity

Understanding the EN 55022 Tangle

EN 55022, based on CISPR 22, is used in the EU and worldwide for measuring radiated and line conducted emissions from ITE (Information Technology Equipment). This standard gets a lot of attention, and is now updated fairly often. A number of issues are under consideration by CISPR that will most likely result in a new 5th edition of CISPR 22 in 2005. Following that will be a new harmonized EN 55022, which may or may not adopt all of the new issues under consideration. 

These include:

• Use of decoupling ferrites for all cables exiting the test area
• Decisions on the manner in which telecom cable conducted emissions should be measured 
• Measurements above 1 GHz. At present, these are not addressed.
• Statistical requirements for data qualification

The EU’s current position on which version of EN 55022 to use is somewhat confusing, and is likely to change soon after a new edition is introduced. At present, manufacturers and laboratories have the choice of applying EN 55022:1994 and all of its amendments, or of applying EN 55022:1998 and its amendments until August 8, 2007. Practically, this means that, for the time being, the use of ferrite isolation on exiting cables and the telecom cable common mode measurement are optional. 

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R. De Vré
EMC-consultant to the European Community 11/04/05

Significance of the date of cessation of conformity for amendments to CENELEC harmonised EMC standards

The following principles apply:

• An amendment has always to be used with the dated edition of a given standard for which it is intended and to which it is attached. This given standard is listed in the OJ EU just above the concerned amendments. An amendment is never used alone or with an older edition of the standard.
• The date of cessation of conformity of the superseded standards related to an amendment (doc/am), which is given in the column next to this amendment, indicates that from this date onwards, the amendment must always be used together with the corresponding main standard in order to obtain presumption of conformity to the EMC directive.
  Before this date doc/am the amendment may or may not be used with the main standard to which it is attached.

Examples:

-1) As amendments are developed some time after the main standard to improve it, in the large majority of cases the doc/am of one or of several amendments is a later date than the doc of the main corresponding standard.

Example

• Main standard edition 1996 doc expired
• Main standard edition 2004 doc/ 01/01/2007
• Amendment A1 to edit 2004 doc/am 01/02/2008
• Amendment A2 to edit 2004 doc/am 01/03/2009

For presumption of conformity:

• Before 01/01/2007: edition 1996 alone or edition 2004 either with or without the two published amendments A1 and A2 may be used
• After 01/01/2007 and before 01/02/2008: edition 2004 shall be used (use of version 1996 is no more allowed for presumption of conformity) either with or without one or the two published amendments
• After 01/02/2008 and before 01/03/2009 edition 2004 shall always be used together with A1. Use of A2 is possible but not compulsory.
• After 01/03/2009 edition 2004 shall always be used together with A1 and A2 to get presumption of conformity

2) In some exceptional cases the date of cessation of the main standard is sometimes postponed and this may result in a situation where the date of cessation of the main standard is a later date than the dates of cessation of one or of several amendments (doc/am)

The same principles apply however in this case:

Example

• Main standard edition 1996 doc expired
• Main standard edition 2004 doc/ 01/01/2010
• Amendment A1 to edit 2004 doc/am 01/02/2008
• Amendment A2 to edit 2004 doc/am 01/03/2009

For presumption of conformity:

• Before 01/02/2008: edition 1996 alone or edition 2004 either with or without the two published amendments A1 and A2 may be used.
• After 01/02/2008 and before 01/03/2009: edition 1996 alone or edition 2004 with A1 shall be used. There is no obligation to use edition 2004 but if one chooses to use it, it shall be used with by A1. Use of A2 is possible but not compulsory.
• After 01/03/2009 and before 01/01/2010: edition 1996 alone or edition 2004 with A1 and A2 shall be used to get presumption of conformity. . There is no obligation to use edition 2004 but if one chooses to use it, it shall be used with A1 and with A2.
• After 01/01/2010: edition 2004 has to be used with A1 and A2. Use of edition 1996 is no more allowed for presumption of conformity

R. De Vré

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EN 55022 and presumption of conformity

At the end of the consolidated list of harmonised standards there is an example which explains the relation between a harmonised standard and on the one hand its previous edition and on the other hand its amendments i.e. the meaning of "Note 3" which reads:

Note 3: In case of amendments, the referenced standard is EN CCCCC:YYYY, its previous amendments, if any, and the new, quoted amendment. The superseded standard (column 4) therefore consists of EN CCCCC:YYYY and its previous amendments, if any, but without the new quoted amendment. On the date stated, the superseded standard ceases to give presumption of conformity with the essential requirements of the directive.

For EN 55022:1998 this means:

It means that:

• Before 01.08.2005 you may use EN 55022:1998 alone or with its A1 or with its A1 and A2.
• After 01.08.2005 you may not use EN 55022:1998 alone but you must use it together with A1. You are not forced to use EN 55022:1998, you can also use the 1994 edition together with its amendments.
• After 01.12.2005 you may not use EN 55022:1998 alone but you must use it together with A1 and A2. You are not forced to use EN 55022:1998, you can also use the 1994 edition together with its amendments.
• After 01.08.2007 you are forced to use EN 55022:1998 together with its A1 and A2 to get presumption of conformity on the basis of harmonised standards. You can no longer use the 1994 edition.

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