 © Nutwood UK Ltd 2001 |
Eddystone Court - De Lank Lane St Breward - BODMIN - PL30 4NQ Tel: +44 (0)1208 851530 - Fax: +44 (0)1208 850871 nutwooduk@nutwood.eu.com |
|
|
|
Compliance with EMC Legislation for High Voltage Switchgear & Controlgear AssembliesBy Peter Ridley, C Eng. MIEE, Amec Process and Energy Ltd |
The EMC performance of the installation depends upon the electromagnetic environment at the installation, upon the EMC performance of the individual assemblies of electrical and electronic equipment that comprise the installation and upon the manner in which these assemblies are installed, maintained and modified. These factors are mainly in the hands of the equipment manufacturers and suppliers, however, the user must do all that is reasonably practicable to ensure that an installation is safe (Ref. 1) and economic to operate. To help in achieving this, appropriate EMC management procedures should be followed (Ref. 2), including the establishment of the intended electromagnetic environments (Ref. 3) and specification of appropriate EMC performance requirements (Ref. 4). These, along with suitable quality assurance and validation activities, should help to ensure that electrical or electronic assemblies incorporated into the installation achieve full and proper compliance with the requirements of the EMC Regulations and related legislation (Ref. 2 & 6).
In March 1996, the Co-ordinating Committee for Common Market Associations of Manufacturers of Industrial Electrical Switchgear and Controlgear (CAPIEL) issued a position paper on "Compliance With EU Directives Relevant To High Voltage Switchgear". This covered four directives - Machinery, Electromagnetic Compatibility, Low Voltage and Construction Products. This position paper was revised in June 1997, following the release of updated EC guidelines on the EMC Directive (Ref. 7).
The UK's BEAMA Transmission & Distribution Association (BTDA), a member of CAPIEL, issued virtually identical position papers. The first, issued on April 1996 (Appendix 1.1), used uncertainty within the EU over CE-marking requirements to justify non-compliance with The EMC Directive. According to the current position paper issued by BTDA in July 1997 (Appendix 1.2), high voltage switchgear or controlgear constitute components and are therefore outside the scope of the EMC Directive.
Individual TSS's expressed the opinion (Appendix 2.1) that HV switchgear assemblies are relevant apparatus which must comply with the EMC Regulations, including CE-marking and issue of a Declaration of Conformity by the manufacturer.
The LACOTS response (Appendix 2.2) included their opinion that whilst individual systems/pieces of apparatus within a power station may well need to comply with the Electromagnetic Compatibility Directive itself, as an excluded installation this would not need to be CE marked.
The DTI response (Appendix A3) included the opinion that apparatus and systems used in 'fixed installations' should individually comply with the EMC Directive if they are single commercial or functional units.
DTI subsequently re-emphasised that installations are a difficult and controversial area. The views expressed are only the DTI views, ultimately, only a court of law can make definitive decisions on interpretation of the law.
HSE's comments (Appendix A4) included the reminder that employers have duties under the Provision and Use of Work Equipment Regulations, 1992, to ensure that work equipment is so constructed or adapted as to be suitable for the purpose for which it is used or provided. Under these regulations (which are enforced by HSE inspectors), employers have a duty to ensure that any item of work equipment complies with legislation implementing any of the relevant Community Directives, the EMC Directive being relevant for an electrical distribution system employing HV switchgear.
NB: Other Directives may have different CE-marking requirements to those of the EMC Directive.
Trading standards services have co-operated from the outset in trying to resolve the differences in interpretation. Increasing involvement of the local authorities is essential in persuading all parties in industry to properly address EMC. One major difficulty for some local authorities appears to be their lack of expertise in the technical aspects of EMC and its relevance for the workplace. This is under consideration by members of a working group within the IEE's Professional Group E2 (Ref. 5 and 10).
EMC specialists recognise that, as a general rule, the later in the engineering cycle that EMC is addressed the more the cost of compliance escalates (Ref. 8).
UK user associations should be taking a common stance to protect the interests of their members, however some appear not to be getting sufficiently involved. As an example, the DTI's survey report (Ref. 9) was presented to an invited audience. Only one of the 24 associations on the "list of representatives" is clearly a USER association, the majority being manufacturers' associations.
The Commission stated its willingness to co-ordinate activities with Member States to ensure that a uniform understanding could be achieved.
In view of this confusion and because it is unlawful to affix the CE Marking to equipment which is excluded from the EMC Directive, until the Member States have reached an agreed position BTDA members will not affix the CE marking to high voltage switchgear and controlgear in respect of the EMC Directive. (Note: Some ancillary low voltage equipment associated with H.V. switchgear may carry the CE Marking in respect of eg the Low Voltage Directive)".
As for the constituent parts of high-voltage electrical installations, such as high-voltage switchgear and controlgear, these can be considered to be components not performing a direct function (see Definition 3.8). There is, therefore, no need for CE-marking, an EC declaration of conformity, or to involve a competent body".
"On the basis of the information in our possession, we were of the opinion that the switchgear package fell within the definition of 'relevant apparatus' and was, therefore, subject to the supply requirements of regulation 30. Consequently the switchgear should satisfy the protection requirements in regulation 5, undergo the conformity assessment procedures and (the manufacturer) should CE-mark and issue an EC Declaration of Conformity".
" From an electromagnetic compatibility point of view it is possible that in theory high voltage switch gear, power stations, etc. could fall within the scope of the Electromagnetic Compatibility Directive, however the DTI consider these to be covered by the term 'excluded installation' under the Directive. What this means in practice is that whilst individual systems/pieces of apparatus within a power station may well need to comply with the Electromagnetic Compatibility Directive itself, as an excluded installation this would not need to be CE marked.
Whilst Trading Standards authorities would have responsibility for all electromagnetic compatibility matters under the EMC Directive and the UK Regulations, their primary concern would be with regard to electrical items sold, distributed or supplied to consumers and in particular those which would come within the scope of the Low Voltage Directive. I appreciate this gives a dichotomy, in that trading standards primary interest is usually in consumer goods rather than in things which are never intended or designed for consumers. It may well therefore be the case that trading standards authorities would not involve themselves directly in high voltage matters. Each local authority will target the resources it considers appropriate to particular circumstances in its own authority. As stated above primary interests may well be in connection with consumer safety matters and thus the focus would be on low voltage rather than high voltage matters.
With regard to the matters raised in the BTDA position paper, if the high voltage electrical installations are fixed installations within the meaning of the Electromagnetic Compatibility Directive, there would seem to be no reason in principle why these products should not be CE marked. However it would be difficult for me to judge in general what is obviously a specific question applicable to specific products. I am aware for example from the consumer sphere that certain products do not require CE marking because individual circumstances dictate that they do not come within the scope of the Directive. I therefore have no particular detail views to express in connection with the statement itself".
"As far as enforcement of the EMC Directive regarding HV switchgear, power generation stations etc. is concerned, HSE do not have a formal enforcement role and whilst the local Authority Trading Standards Departments are the responsible authority this is not their traditional area of operation. Any problems in this area (I believe that HSE have indicated that they are not aware of any evidence of any significant risk to safety relating to EMC and HV switchgear) will be looked into by either or both parties before a decision is taken on any action that may be required and who should undertake it.
Power stations and other installations which are site specific and do not cross national borders are likely to be viewed, in the new EMC Guidelines, as only being required to meet the protection requirements of the Directive, not requiring CE Marking, a Declaration of Conformity, or to have followed one of the routes to conformity. However, individual apparatus/systems within the installation will still need to comply with the Directive where relevant".
On your second point, the Regulation and sections of the EMC guidelines referred to above are again relevant. Apparatus and systems used in 'fixed installations' should individually comply with the EMC Directive if they are single commercial or functional units.
On your third point, I suggest that it is likely that the Technical Construction File (TCF) route to compliance would be widely used. However, I am sure that some apparatus/systems used in 'fixed installations' will be able to comply by means of either generic or product specific standards.
Generally I would suggest that installations are a controversial area. Each installation should be taken on a case by case basis, agreement must be reached at an early stage between designers, manufacturers, installers and operators of the installation as to the nature of the installation's electromagnetic environment. This will enable all involved to clearly understand their responsibilities under the EMC Directive. Ultimately, the installation must meet the protection requirements of the Directive when it is taken into service.
I should point out that the EMC Guidelines are just that guidelines, in cases of conflict the implementing regulations and ultimately the Directive take precedence.
Finally, the views expressed above have been discussed and agreed with LACOTS, however, these are just the views of DTI and LACOTS, ultimately only a court of law can make a definitive decision on such matters".
"From a safety viewpoint, Section 6 of the Health & Safety at Work etc. Act (HSW) places duties on those who design, manufacture, import or supply any article for use at work. Essentially, the duties under Section 6 are designed to ensure that risks to health & safety which might result from the use of articles (and substances) at work are reduced to a level which is as low as reasonably practicable.
When the article being supplied comes within the scope of the legislation resulting from the EC 100A 'product' Directives then that legislation will normally take precedence over domestic legislation (that is, a 'CE' marked item will normally be deemed to comply with Section 6).
However, when the article being supplied is outside the scope of the European driven product legislation, then the HSW Section 6 duties come into force.
Therefore, in the event that HV switchgear is considered, for whatever reason, to be outside the scope of European product legislation, then the designers, manufacturers, etc. of the switchgear have duties to ensure that the switchgear is designed and constructed so that it will be safe and without risks to health at all times when it is being set, used cleaned or maintained by a person at work. They have also to carry out or arrange for the carrying out of such testing and examination as may be necessary to achieve this end and to take steps to secure that persons supplied with the switchgear are provided with adequate information (including any revisions) about the use for which the switchgear is designed or has been tested and about any conditions necessary to ensure that it will be safe etc.
I would expect these duties to encompass any actions which may be necessary to allow the HV switchgear to be installed and used so that any electromagnetic disturbances emitted by the switchgear do not unduly hinder the operation of other equipment (which might reasonably be expected to be used in the intended environment) in a way which might lead to danger. In the event that any aspect of the operation of the HV switchgear could lead to danger in any reasonably foreseeable circumstances resulting from the exposure of the switchgear to electromagnetic disturbances at levels likely to exist in the intended environment, then I would also expect the switchgear to possess an adequate level of immunity to electromagnetic disturbances to avoid such danger.
You may also wish to note that employers have duties under the Provision and Use of Work Equipment Regulations, 1992, to ensure that work equipment is so constructed or adapted as to be suitable for the purpose for which it is used or provided. Under these Regulations (which are enforced by HSE inspectors), employers have a duty to ensure that any item of work equipment complies with legislation implementing any of the relevant Community Directives. I would regard the EMC Directive as being relevant for an electrical distribution system employing HV switchgear.
In the event that inadequate electromagnetic compatibility is the cause of an unacceptable risk to peoples health and safety I am confident that HE inspectors, if necessary in liaison with other enforcement bodies, would take action as appropriate to reduce the risks considering all the circumstances at that time."
Mr Ridley thanks LACOTS, the DTI and the HSE for permission to quote from their helpful and constructive comments, however, other opinions are expressed as those of the author alone.
Peter can be contacted at Amec Process and Energy Ltd, 5th Floor, 1 Golden Lane, London, EC1Y 0RR, phone: 0171 574 3457, fax: 0171 574 3900.
|
© Nutwood UK Ltd 2001 |
Eddystone Court - De Lank Lane St Breward - BODMIN - PL30 4NQ Tel: +44 (0)1208 851530 - Fax: +44 (0)1208 850871 nutwooduk@nutwood.eu.com |
|
|
|