Equipment Protection Levels (Documenting risk assessment when classifying zone areas)

Abstract

The IEC-based term “Equipment Protection Levels (EPLs)“ refers to a disciplined process for identifying and selecting equipment for installation in hazardous (classified) locations. This disciplined process involves special equipment markings, an optional comprehensive risk assessment after area classification, and a selection criteria to identify the equipment that can be installed in hazardous (classified) locations. The optional comprehensive risk assessment involved with this process is subsequent to the classification of the area, and may allow for the selection of equipment that would not normally be associated with the involved area classification designation. And while the term EPLs may be relatively new and all aspects of the concept not fully implemented in the US, the concept of assessing the risks and consequences associated with a classified area, and the utilization of mitigation methodologies to address the selection of equipment for a given classified area, is not new. For example, the use of combustible gas detection systems and pressurized enclosures are common mitigation methodologies in US classified areas. A broad-based perspective on adoption and implementation of all aspects of these EPL concepts in the US will be provided by representatives from US codes & standards, product certification, area classification and installation communities.