IEEE 1349-2021: Electric Machines in Hazardous Locations: Worldwide Applications

IEEE Standard 1349-2021,
IEEE Guide for the Application of Electric Machines in Zone 2 and Class I, Division 2 Hazardous (Classified) Locations
, primarily focuses on techniques and tools to limit motor overtemperature and sparking that could ignite flammables. The emphasis is on the use of open or nonexplosionproof enclosed or nonflameproof enclosed machines including precautions against excessive surface temperatures and sparking of rotor bars and enclosure joints. To mitigate hot surface temperatures and sparking, this document provides guidance for selecting, operating, and maintaining electric machines where flammable gases and vapors may occasionally be present. The third edition has been updated for the 2020 National Electrical Code (
NEC
), and guidance has been added for the 2021 Canadian Electrical Code (CE Code). The guide has been expanded to harmonize internationally and has been updated for IEEE Standard 841 for totally enclosed fan cooled (TEFC) motors and IEEE P303 for auxiliary devices. Some elements from the International Electrotechnical Commission (IEC) Increased Safety standard are included. This article provides an overview with highlights of key elements, discusses worldwide applications, includes new space heater tests and applications, and describes a new test method to determine the permanent magnet (PM) motor rotor temperature. Machine temperature test information has been summarized along with adjustable speed drive (ASD) test configurations. An overview and uniform resource locator link are provided for the inaugural IEEE 1349 Discharge Energy Calculator used to prevent incendive sparking due to common-mode voltage (CMV) for ASD applications.