DTI are at: http://www.dti.gov.uk
Chris > -----Original Message----- > From: tinb...@aol.com [SMTP:tinb...@aol.com] > Sent: Wednesday, June 10, 1998 8:24 PM > To: emc-p...@ieee.org > Subject: Re: CE technical file format > > Gary, > > UK's DTI published a "Guidance Document on the Preparation of a > Technical > Construction File as Required by EC Directive 89/336" dated October > 1992, > which contains some helpful information on what a manufacturer should > include > within a Technical Construction File. > > The key parts of that Guidance Document were also captured within > Annex B > (Technical Construction File Route to Compliance" of the DTI's UK > Regulations > April 1993 "Product Standards, Electromagnetic compatibility". > > You should be able to obtain the above documents from DTI directly. > For your > convenience, I have included the relevant excerpts below: > > Annex B - Technical Construction File Route to Compliance > > BASIC REQUIREMENTS FOR A TCF > > Part I: Description of the apparatus: > i) identification of apparatus; > ii) a technical description. > > Part II: Procedures used to ensure conformity of the apparatus to the > protection requirements: > i) a technical rationale; > ii) details of significant design elements; > iii) test evidence where appropriate. > > Part Ill: A report or certificate from a 'Competent Body'. > > SPECIFIC REQUIREMENTS FOR A TCF > > The level of detail required in each of the above sections of the TCF > will > depend on individual circumstances, but might include the following: > > > Identification of the apparatus > (a) brand name; > (b) model number; > (c) name and address of manufacturer or agent; > (d) a description of the intended function of the apparatus; > > (e) for installations - physical location; > (f) external photographs; > (g) any limitation on the intended operating environment. > > > Technical description of the apparatus > (a) a block diagram showing the interrelationship between the > different > functional areas of the apparatus; > (b) relevant technical drawings, including circuit diagrams, assembly > diagrams, parts list, installation diagrams; > (c) description of intended interconnections with other products. > devices etc. > (d) descriptions of product variants. > > Technical rationale > (a) a brief exposition of the rationale underpinning the > inclusion and > balance of the evidence given. > Detail of significant design aspects > (a) design features adopted specifically to address EMC problems; > > (b) relevant component specifications (e.g. the use of cabling > products known > to minimise EMC problems); > (c) an exposition of the procedures used to control variants in the > design > together with an explanation of the procedures used to assess whether > a > particular change in the design will require the apparatus to be > retested; > (d) details and results of any theoretical modelling of performance > aspects of > the apparatus. > Test data > (a) a list of the EMC tests performed on the product. and test reports > relating to them, including details of test methods, etc. > > (b) an overview of the logical processes used to decide whether the > tests > performed on the apparatus were adequate to ensure compliance with the > directive; > (c) a list of tests performed on critical sub-assemblies, and test > reports or > certificates relating to them. > > Report or certificate from a competent body > (a) reference to the exact build state of the apparatus assessed, > cross > referencing with Part I of the basic requirements of a TCF; > > (b) comment on the technical rationale; > (c) statement of work done to verify the contents and authenticity of > the > design information in the TCF, cross-referencing with Part II (ii) of > the > basic requirements of a TCF; > (d) comment, where appropriate, on the procedures used to control > variants, > and on environmental, installation and maintenance factors which may > be > relevant; > (e) contain an analysis of the tests performed either by the > manufacturer, an > authorised third party, or the competent body itself, and the results > obtained, so as to assess whether those tests indicate that the > apparatus > should comply with the essential requirements of the Directive, cross- > referencing with Part II (iii) of the basic requirements of a TCF. > > > It is envisaged that Parts I and II of the TCF will be written by the > manufacturer in cooperation or consultation with the Competent Body. > The > report from the Competent Body should therefore not need to repeat > much of the > information contained in Parts I and II. > > At the end of the report a detachable certificate will be supplied. > This can > be used by the manufacturer as an indicator of compliance where it is > felt it > would be inappropriate to submit the entire report. It is possible > that where > Parts I and II of the report prepared by the manufacturer largely > 'speak for > themselves', the Competent Body might prepare a certificate only. > > It should be emphasised that the manufacturer is ultimately > responsible for > the declaration of conformity of products certified via the TCF route. > The > role of the Competent Body is to assert that the evidence contained > within the > TCF is consistent with conformity. It is the manufacturer's > responsibility to > ensure that the information is correct and that subsequent production > units > are consistent with it. > > > SUGGESTED TCF CONTENTS IN FIVE POSSIBLE CIRCUMSTANCES > > i) For apparatus where there is no applicable harmonised EMC > standard > (although the availability of generic standards theoretically means > that a > standard exists for every product, it is recognised that in practice > their use > may not be practicable for some products). > > There may well be cases where a specific standard for a given product > does not > exist, and the generic standard is not considered appropriate, but > nevertheless it will be in the manufacturer's best interests to > assemble test > data of some sort as the best method of demonstrating compliance with > the > protection requirements. > > The emphasis will therefore be on drawing up, in collaboration with > the > Competent Body, a test programme suitable for the type of product > being > assessed, and on demonstrating the validity of this programme, rather > than on > a detailed analysis of the EMC protection methods used in the > apparatus Part > II of the TCF (procedures used to ensure conformity) will reflect > this, but > Part I will still have to contain sufficient detail to identify the > product. > > ii) For apparatus where harmonised standards exist but the > manufacturer > applied these standards in part only (e.g. where a manufacturer can > justify > that a particular type of apparatus complies with the protection > requirements > of the Directive without performing tests to any or all of the > phenomena > described in the relevant harmonised specifications). > > Under the circumstances where harmonised standards have been applied > in part > only, it is envisaged that the TCF will seek to demonstrate why tests > for > certain phenomena were not felt to be necessary. > > It is likely that the emphasis of the TCF will be on the construction > of the > apparatus; in particular to demonstrate what special properties the > apparatus > demonstrates which render as unnecessary some or all of the tests > described in > the relevant harmonised standards. > > The technical description of the apparatus is therefore likely to be > extensive, making easier the theoretical justification for not > performing > tests in the technical rationale. > > iii) For installations where testing to harmonised standards is not > practicable due to the physical properties (e.g. size, location) of > the > installations. > > It is envisaged that there may be occasions where, because of the > physical > properties of an installation, it is not practicable to perform tests > according to harmonised standards. For instance, the installation > might be too > large, or it might operate in such a way that the tests could not be > conducted > using established procedures. > > Under these circumstances, the role of the TCF is to define a > framework within > which the creator of the installation can operate and remain confident > that > the apparatus which makes up the installation complies with the > essential > requirements of the Directive. > > The description of the apparatus should therefore include details of > the > physical location of the installation and also any relevant > characteristics of > the physical location, e.g. the composition of the building in which > the > installation is housed, and any significant local environmental > factors such > as close proximity to a recognised source of electromagnetic > disturbance. > Given the difficulty of performing tests on the installation as a > whole, Part > II will concentrate on tests performed on the apparatus comprising the > installation, design steps taken to deal with EMC and adherence to > installation and maintenance codes of practice. > > iv) For products where the testing of each individual product to > harmonised > standards is not practicable due to the large number of similar > product > variants. > > It is envisaged that certain kinds of products and installations will > be made > available as large numbers of broadly similar product variants, > perhaps to > meet particular customer specifications. Examples of this might be > local area > networks in offices or custom variants of commercial vehicles. > > The TCF in these cases must concentrate on the design principles which > are > consistent throughout the whole family of product variants, the steps > taken to > ensure that variants are consistent with these principles and the > specifications of, and tests performed on, critical components and > sub- > assemblies. > > Part I might therefore need to include identification of variants (or > broad > families of variants where listing every individual variant would be > excessive), block diagrams showing typical interrelationship between > functional areas and a description of the principal components and > sub- > assemblies used in the product. > > Part II would include design features generally employed to reduce EMC > problems (including the use of components of a particular > specification) and > tests carried out, where appropriate, on sub-assemblies and on typical > installations > > In the case of system variants such as local area networks, details > might also > be included of any instructions to installers or users indicating > appropriate > installation and maintenance codes of practice. > > v) For products having existing certification to EMC standards not > recognised > by the EC, but which are nevertheless regarded as indicating > compliance with > the protection requirements of the Directive. > > It is recognised that compliance with some EMC standards not as yet > officially > recognised by the European Directive will indicate compliance with the > essential requirements of the Directive. Such standards might include > military > standards, national civil EMC standards, or standards generated by > industry. > > In such cases, the TCF could concentrate on the coverage of the > standard (ie > whether additional verification was needed in regard to phenomena not > covered > by the standard in question, but addressed in the Directive), the > performance > levels required by the standard and the test methods employed. > > > Hope this helps. > > Tin
