Although competent bodies may be used as independent expert advisors whose word may be more readily believed by a customer and a court than a supplier who is an interested party in a transaction, this is not their official function.
The only official function under the EMC directive is to issue a report or certificate on technical construction files from those chosing to use the TCF route to demonstrate compliance with the general protection requirements. The essential points about the TCF route is that it is not inherently tied to the harmonised standards and that via it a single DoC may be made to cover a wide range of variants on a basic product. If you do not wish to avail yourself of this flexibility and can show that equipment fully complies with the harmonised standards there is no need to use a competent body. As has been pointed out with all four generic listed in the OJ the no applicable standard clause in the directive is now of no significance. From the legal point of view Company A's view on this is irrelevant. Since however Company A is, in principle, liable for taking into service equipment should it fail its general protection requirements it may wish to have more assurance than your word that the equipment does meet these requirements. It may impose a contractual requirement that a report be obtained from a competent body or an accredited test house in the same way that it can impose a requirement that it be painted green with pink spots. However in the case of a large item like a flight simulator it is difficult show compliance with the harmonised standards. Getting an item that big onto an open area test site and rotating it to check radiated emissions from all directions is difficult and expensive. There are few anechoic chambers big enough to take such items for the radiated RF immunity measurements and they are expensive to hire. Such items are also prone to be customised for each sale. It therefore looks a good candidate for where a TCF and competent body report is the cheaper option. Competent bodies will usually accept extension to higher frequencies, say 230MHz, of the current injection measurements used for the conducted immunity measurements. These tests do not need an anechoic chamber. At a penalty of a few extra dB on the limits to allow for uncertainty a competent body will usually accept measurements made on a non-regulation test site such as the factory floor. With a few tests on optional extras and technical arguments as to why these represent worst case you may be able to get a TCF approved that covers a whole range of equipment. As has been pointed out before, the classification of the generics between domestic, commercial & light industrial and industrial is independent of the Class A and Class B classification of EN55022. If you are applying EN55022 directly as the applicable listed harmonised standard then you are not applying the generic emission standard and its classifications are irrelevant. You apply the criteria for Class A or Class B. If however you conclude that EN55022 does not directly apply to your equipment and in the absence of any other applicable standard you fall back on the generics you use the classification of those standards. If you conclude that the equipment is for a domestic, commercial light industrial environment you will be directed to apply EN55022 Class B and EN 55014 as basic standards. This means that you use them for the test methods and test set-up only. Any stipulations about scope and classification in those standards is non- applicable because these are given by the generic standard. In any event it is not up to the customer to decide which environment to apply. It is up to the manufacturer or his agent to decide which environments the equipment will need to operate in, show compliance in those environments and specify those environments in the equipment literature when it is supplied. The customer should only take equipment into service in environments for which it is specified. Victor Boersma states that such a flight simulator should be subject at least to the EMC, Low Voltage and Machinery Directives. The LVD and the Machinery directives are generally considered mutually exclusive. If the major safety hazard is electrical apply the LVD else apply the Machinery directive. This view has been given in various guidelines and in the UK implementation of the machinery directive 'The Supply of Machinery (Safety) Regulations 1992@ Statutory Instrument 1992 No. 3073 if spells this out explicitly In the section on exclusion of machinery covered by other directives, regulation 10 (1)(b) it says 'These regulations do not apply to- (b) machinery which is electrical equipment in so far as the risks as to the safety of such equipment are mainly of an electrical origin.' In the section on consequential disapplication of United Kingdom Law it states in regulation 34: '(1) the low voltage Electrical Equipment (Safety) regulations 1989 are hereby disapplied in respect of relevant machinery which is electrical equipment in so far as the risks to the safety of such equipment are not mainly of electrical origin. (2) In this regulation, 'electrical equipment' has the meaning given by article 1 of Council Directive 73/23 EEC on the harmonisation of the laws of member States relating to electrical equipment designed for use within certain voltage limits' Nick Rouse
