EMC, CE marking and all that jazz........

What’s EMC? What’s CE marking? What’s it all about? Aaargh!

This is a huge subject and one which we will attempt to clarify as simply as possible.
Read on............

EMC

The European EMC (Electro-magnetic Compatibility) directive has been around for some time now. It states (in its simplest form) that any electrical or electronic equipment on sale in the UK from 1st January 1996 must have been tested by an approved test house and must comply with its relevant testing standard.

This is now mandatory.

It is now illegal to sell any applicable equipment in the UK that has not passed these tests.
There is a slight (temporary) loophole that exists for traders to sell equipment that has not passed the tests provided that the goods in question were in the country before 1st January 1996. Proof of this may be required and it is advisable to contact your local trading standards officer to inform the TSO of your intention to sell the equipment and get their approval. This should be just a formality.

The CE Mark

For the Professional Sound Industry, CE marking is now a requirement too. Any product requiring EMC testing will require a CE mark. According to the regulations, products not requiring EMC certification will have to have a CE mark but this was not mandatory until 1st January 1997.
Basically, a product that has a CE mark attached is deemed to have passed all the relevant safety and emissions tests. Interestingly, the safety regulations include persons and domestic animals with the "risk" factor applied to "damage to property". When the manufacturer or its agent affixes the mark, the product is said to be fit for sale anywhere in the EU.

Before the mark is attached, a "Declaration of Conformity" must be drawn up and signed by the manufacturer stating the following :-

1. Identification of product
2. Name of manufacturer or responsible importer in the EU.
3. The Standards applied.
4. A declaration of when the CE marking was applied to the product.
5. A declaration that the relevant directive has been observed.
6. The signature of the manufacturer or his responsible representative in the EU.

If the product is manufactured outside the EU, it is also an advantage to have the foreign manufacturer sign the declaration. The documentation must be in English and in a legible form. For the purposes of inspection, legible reproductions are acceptable.

Failure of the manufacturer’s agent to retain such documentation is an offence. The documents (including technical documentation) must be retained for a period of ten years after manufacture of the product has ceased. This must be available at all times for inspection.

It is important to note that the CE mark encompasses all the tests necessary for the product to be sold in the EU. Just because a product has passed EMC tests does not imply that the CE mark can be affixed to the product. It has to pass all the relevant safety and approval tests as well. If the product is a radio transmitter product, it will also have to pass Radio Regulatory Approvals too.

The EMC testing standards vary from product to product and as a result it can be difficult to decide exactly which document or standard to actually test to. There are a number of so-called "Generic" standards that are deemed to apply to most products without actually being specific as to what they are.
At present, most professional audio type equipment is tested to a "Generic" standard. This standard is a little "loose" and is open to interpretation by manufacturers, test houses and trading standards officers.

In short, as long as the manufacturer is shown to have conformed to a reasonable interpretation of this document it is possible to pass the tests. There are other methods such as a "Technical Construction File" method whereby the manufacturer "builds" the unit to a pre-arranged standard and "self certifies" the unit without it even being tested. This is easier for the manufacturer but the manufacturer has to categorically state that it feels that the product will pass and has to submit all the necessary technical documentation for it to be accredited and approved by a competent body. In this case a "Presumption of conformity" will be deemed to be in force until the contrary is proved.

As an aside, note that for the Regulations contain the following, and I quote:

" A nuclear electromagnetic pulse shall not be regarded as electromagnetic disturbance "!

If this isn’t - what is? !!

Product Marking

At present, the CE mark must be on the product or its packaging, instruction sheet or guarantee certificate.

For identification purposes, it makes sense to mark the lot but with small products, the size of the product may render it impossible to label. The regulations state that the label must be visible, easily legible, indelible and at least 5mm vertical height but even this is too large for some items.

FAQ’s (Frequently Asked Questions)

Q. So what is the EMC testing all about?
A. In its basic form, EMC (electromagnetic compatibility) concerns the ability of relevant apparatus to function satisfactorily in its electromagnetic environment without introducing intolerable electromagnetic disturbance to anything in that environment and have a level of intrinsic immunity which is adequate to enable it to operate as intended when used for its intended purpose and when it is properly used and maintained. Basically, it should not generate interference and should be reasonably immune to outside interference. Most professional audio products fall into this category anyway - even without the EMC regulations.

Q. What needs EMC approval ?
A. The regulations state all electrical apparatus such as the following :-
An electrical appliance
An electronic appliance
A system.

Q. Do the regulations apply to spare parts ?
A. No. Spare parts are specifically excluded.

Q. I’ve been told that all amplifiers must now have Speakon connectors fitted in order to pass the regulations. Is this true ?
A. No. The regulations state that there must be no exposed metal parts on output terminals if the output voltage of the device is likely to exceed 50V. The only exposed metal part on a banana (binding post) type terminal is the hole that you can push the plug into. Manufacturers can meet specification by inserting a plastic plug in the hole to shield the metal part of the terminal. Some manufacturers meet the spec by including a removable metal or plastic shroud which fits over the top of the whole connection post. Bear in mind that it simply would not happen that a government body would include a specific make and model of connector within a specification document. The document includes guidelines as to the type of shielding and safety requirements for the output terminals. It does not specify a connector.

Q. Does my amplifier have to have a 13A plug fitted ?
A. No. The laws on "Domestic" appliances now require plugs to be fitted, but as professional sound equipment is not considered to be "Domestic" this law does not apply. Most manufacturers do, in fact, fit plugs.

Q. I hire equipment out. Does it have to be CE marked ?
A. No. The directive excludes equipment for hire, but for you to have bought it in the first place within the EEC it would have had to be CE marked if purchased after 1st January 1996.

Q. I sell second hand equipment. Do I have to get it tested and marked in order to put it up for sale ?
A. No. The directive excludes second hand products.

Q. I’ve just bought some loudspeakers. They are not CE marked. Is this allowed ?
A. A tricky one this. The regulations state that they do not apply to apparatus which is electromagnetically benign (i.e. the inherent qualities of the apparatus are such that it is neither liable to cause, nor its performance liable to be degraded by electromagnetic disturbance). Loudspeakers as such, fall into this category but it could be argued that if the unit contains a crossover with large chokes then it may be liable to radiate. The possibility of the loudspeaker interfering with anything else is so small that it is not likely to be an issue. Bear in mind though that TV’s and computer/video monitors are of course affected by loudspeaker magnetic fields.

Reference Material.

There are a number of publications that clarify all of the necessary regulations. These are listed below :-

1. Statutory Instrument 1994. No.3260. Consumer Protection Electrical Equipment Safety Regulations 1994. - HMSO £2.40

2. EMC Statutory Instrument 1992. No.2372. Electromagnetic Compatibility/EMC regulations. - HMSO £7.35

3. Statutory Instrument 1994. No.3080. Electromagnetic Compatibility (Amended Regulations) 1994. - HMSO £1.95

4. DTI Guide To UK EMC Regulations. Product Standard Electromagnetic Compatibility Guidance Notes. May 1995. No.URN95/683. - DTI no charge.

5. Product Standards Electrical Equipment (Implementing the L.V. Directive). Guidance Notes On UK Regulations. July 1995. No.URN95/626. - DTI no charge.

6. EMC Europe. Understanding EMC regulations. Includes all relevant laws in EC countries and how they are applicable to the standards. Regular updates available. £144.00 members, £184.00 non-members.

*Note: All prices correct at time of being put live.

Contacts

HMSO
Enquiries : 020 7873 0011
Orders : 020 7873 9090

DTI
Enquiries : 020 7215 0376
Business Support unit : 01179 444888

BSI
Information Centre :020 8996 7111 (Voice)
:020 8996 7021 (Voice)
:020 8996 7048 (Fax)
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