What Are The Driving Forces In The Selection Of A Hazardous Location Electric Motor - Divisions Vs Zones?

Abstract

The National Electrical Code (NEC) [1] and Canadian Electrical (CE Code) [2] both discuss the installation requirements for an electric motor to be installed in “Division” or “Zone” hazardous locations. Also, both the NEC [1] and the CE Code [2] discuss the interchangeability provisions for “Division” and “Zone” area classifications, meaning that one can install a “Division” area suitable motor in a “Zone” area or vice-versa. Even though the interchangeability is permitted, the motor design, materials, and accessories may differ due to testing and marking requirements of the country-specific adaptations of UL, CSA, or I EC standards. These requirements impact the cost and delivery of the motor. Stock, or off-the-shelf products, may not be able to be utilized. This paper covers the design, construction, and testing differences between a motor that is “identified for use” in a Division 2 or a Zone 2 location, versus one that is not. Motor accessory devices and the end users’ perspectives are also included.