EMC on AC motors-advice, tips and hints

Trends indicate that variable speed AC drives are already well established in the cement industry. However, as the use of these low maintenance drives, becomes more widespread, so do the associated problems. One such problem is that of electromagnetic interference (EI). EI can lead to de-rating when dimensioning the motor and modification of installation practices. In fact the need to take EI into consideration is no longer just recommended, it is rapidly becoming imperative. This paper deals with the background to these problems. Advice is also given on what is important for AC variable speed drive installation, plus recommendations are given to potential purchasers of AC drive systems.