What does an EMC laboratory do?

Firstly, the Electromagnetic Compatibility of Equipment Act (EMC Act) actually requires testing by law. In principle, however, the electromagnetic compatibility (EMC) of equipment ensures a high level of interference immunity and limits interference emissions. Depending on the product and area of application, the requirements for electromagnetic compatibility can be more lenient or stricter. If a piece of equipment, such as a frequency inverter, is subject to electromagnetic interference, the machine will, in the simplest case, come to a standstill for a while. However, machine damage or even personal injury is also conceivable. To prevent this from happening, products are tested for their EMC. 

Good “product EMC” is powerless against poor “environmental EMC”. Current physics describes coupling mechanisms that are always present. They can only be specifically weakened or consciously utilised to ensure good EMC of the system. This requires a basic understanding of EMC on the part of the system designer. But even engineers who have been dealing with EMC for years still fall into one or two EMC traps. Precisely because the subject is very complex, KEB provides good instructions on how to achieve EMC-compliant installation in practice. 

We first define operating states that are representative of customer applications and of course cover the majority of the functions that our inverters provide. In terms of standards, we have to define cases that cause the greatest interference emission, for example, or where the inverters tend to be the most sensitive. On the one hand, we test the immunity and emission in an anechoic chamber and, on the other hand, conducted in a shielded cabin or at special pulse stations. If the inverter exhibits undesirable behaviour in the EMC test, the result is documented accordingly in a test report. Once all the tests for a product have been completed and documented, the weak points identified are analysed and corrected during development. In addition, the optimisations are incorporated into the product development process for the entire range of devices.

There are so-called product standards for all possible products. For frequency inverters, for example, we mainly apply DIN EN 61800-3 for EMC and also DIN EN 61800-5-2 for functional safety. In addition, we at KEB have defined our own factory requirements, which are stricter than the requirements from the product standards. In this way, we ensure that we do not develop “on the edge”.  We also get a feel for what our products are capable of. This makes our work in the development process a little more flexible. However, we also consciously sound out weaknesses in order to eliminate them in the product cycle where possible. 

We can advise our customers on site and carry out measurements during development. You also have to keep an eye on the environment, which is not always sufficiently emission-free. We can also carry out immunity tests to a limited extent. We also offer EMC training courses that include both theoretical and practical elements. This is an ideal opportunity for system designers to develop a feel for EMC. Our EMC guide is highly recommended for those who would like a theoretical introduction to the subject. Customers are welcome to contact our sales department at any time for measurements and training.