Using Ex nA Motors Safely: Myths About Prestart Purging, Ventilation, and Pressurization in Zone 2 Motors

The authors discuss the importance of such features in Ex nA motors with respect to the present and most up-todate International Electrotechnical Commission (IEC) 60079-15 [9] standard of Ex nA motors. At the same time, various applications, associated risks, and the proper selection of this expensive large motor feature are discussed.The different aspects of design and application are considered, comparing the North American and IEC standards in terms of safety to identify a clear selection of such features. Ultimately, this article provides guidance for those who are considering implementing this expensive design when they could seemingly select and apply the right Ex nA motors for the right application and location without such features.