DWH Technical Topic: Electric motors in hazardous areas

By Clarence Klassen, P. Eng.

An article in IEEE Industry Applications, Vol. 19, No. 6, p.28, titled “Installation of Electrical Motors: Do Not Mix the Requirements of Hazardous Location Areas” by Mistry and Lawrence discusses installing motors in hazardous or explosive areas. It lists the standards applicable to these applications in the USA, Canada, and Europe. An explanation of these standards is provided.

The IEC Equipment Protection Level (EPL) applies worldwide and lists Ex n motor codes distinguished with a letter.

Standards are not as clear in the USA and Canada with limitations on temperature and sparking specified. The NEC refers to AE x n motor codes.

I have been privileged to contribute to the testing of some motors in the facilities mentioned and shown in the photos in the article.