Converter-fed motors for use in potentially explosive atmospheres

Asynchronous motors in conjunction with converters are being used more and more for the speed regulation of electric drives, even in the field of explosion protection. The speed regulation provides a suitable method for the control or regulation of chemical and petrochemical processes. Beside the advantages of asynchronous motors, compared to mains operation there are, however, some disadvantages involving planning and testing that affect the explosion protection. This paper provides an introduction to the particular problems of converter-fed asynchronous motors for use in potentially explosive atmospheres.