The background to electromagnetic compatibility (EMC)
Within the framework of the harmonisation of national regulations, EMC guidelines were drawn up and, on November 9, 1992, incorporated in the Electromagnetic Compatibility Act.
One result of this is the need to test not only radio-operated equipment but also all electrical and electronic devices, equipment and systems in respect of electromagnetic compatibility. The aim of these checks is to issue the CE mark, which is required for the operation of all electrical devices and equipment since January 1, 1996.
If EMC compliance cannot be achieved by a circuit design which conforms to electromagnetic compatibility and/or by means of a metal internal encapsulation, the appropriate measures can be taken on the enclosure side.
A study of the EMC cost factor produced the following results
| Taking EMC into consideration | Cost factor |
| during development | 1 |
| at series readiness | 100 |
| in use | 1000 |
From these figures, it can be deduced that when it comes to selecting an enclosure, in 90% of all cases, electronics which conform to EMC can be incorporated in every required enclosure without any additional work or expense.
This means that there is no need to do without the main advantages of plastic enclosures because screening is being used. These advantages include:
- attractive desi
- considerable price advantage
- much lighter, more variable
Our offer – screening in conjunction with plastic enclosures
BOPLA can give you competent advice and assistance when you need to protect your electronics against external influences. We offer three methods to give you the required level of protection.
In all those cases in which the above-mentioned processes do not provide adequate screening, the fitting of contacting seals can provide additional screening protection. If necessary because of customer-specific requirements and the type of enclosure, we can recommend or specify, and supply, such special seals.
If components, modules or the complete electronics are at risk of being affected by any kind of interference, an additional and effective method of screening involves equipping such parts with an internal metal encapsulation. An increase in the level of screening protection can also be achieved with such a metal enclosure by means of the methods described above.
To complete the EMC protection measures, the cable inlets can be supplied with suitable plastic or metal cable glands with the possibility of attaching the cable screening to the enclosure earthing connection.
Our offer – screening for aluminium enclosures
Because of their material, aluminium enclosures offer a certain level of EMC protection. However, for optimal EMC applications, it is necessary to fit the joints (groove-spring) with suitable conductive seals. However, in this case, note that the coats of lacquer need to be bridged. This can be done by means of suitable conducting seals and by removing the layers of lacquer. The extent of the work involved must be determined when the requirements are clarified.
