|
Disturbance-Free Electrical Appliances
In addition to being safe, reliable and easy to maintain, electrical appliances must also be disturbance-free in various environments. Appliances that fulfill these requirements are electromagnetically compatible. Electromagnetic compatibility (EMC) means that the equipment does not introduce intolerable electromagnetic disturbances into its environment, and is not affected by such disturbances.
The Electromagnetic Environment
For the satisfactory functioning of electrical appliances, different disturbance levels have been determined for residential and industrial areas. All electrical equipment can be made compatible with its environment by attending to the following issues:
- No appliance may produce disturbances exceeding the agreed level.
- All appliances must be able to withstand disturbances up to the agreed level.
Electromagnetic Emissions
Any phenomenon by which electromagnetic energy emanates from the equipment (except as originally intended) is considered an electromagnetic emission. Interference on a TV screen, cracking noises on the radio and operational failure of information technology equipment are often caused by other appliances. Such disturbances can be transmitted from one device to another, either through wiring, or electromagnetic radiation.
Immunity
All electrical equipment must also be able to function properly in the presence of electromagnetic disturbance from the environment. For example, electromedical equipment in hospitals may be disturbed by mobile phones used nearby. The use of mobile phones is, therefore, usually not allowed in such environments.
Summary of the European Union’s EMC Requirements
The manufacturer of the product, the manufacturer’s representative or an authorized importer shall make sure that the product to be produced or assembled conforms to the requirements of the EMC directive and any other valid directives. These directives include, among others, the low-voltage machinery and gas appliance directives.
A manufacturer who applies harmonized standards may use a Competent Body, for example SGS Fimko, for product testing. Manufacturers, who do not apply harmonized standards, must submit their products for testing by a Competent Body. The most economical alternative is to use a Competent Body, for example SGS Fimko, in order to avoid having to test all products in a large product series according to a particular standard. The Competent Body can choose the appropriate tests, the extent and costs of which are smaller.
|
