Luminaires for explosive atmospheres: Evaluating new technologies from the IEC and NEC perspectives

Nationally Recognized Testing Laboratories (NRTLs) and Explosive Atmosphere Notified Bodies (ExNBs) test luminaire products to IEC, CENELEC and ANSI standards in order to rate products appropriately for use in potentially explosive atmospheres. The ultimate goal of this testing is to ensure safety for end-users-a goal that is shared by design engineers, manufacturers, testing bodies and end-users alike. Despite the shared goal of safety, however, the specifics of luminaire design, construction, testing, installation and maintenance can vary widely, raising questions about how standards should be interpreted and applied. IEC and ANSI provide similar standards, and we endorse the ongoing convergence toward a global set of harmonized standards. But as new technologies emerge, standards must continue to evolve, while manufacturers and testing bodies must continue to evaluate and fine-tune their interpretation of standards in real-world conditions. Safety, as always, should be the number-one concern. This paper discusses existing and emerging luminaire technologies in the light of current standards and testing methodologies, and proposes best practices that go beyond the standards to ensure the safety of luminaire products installed in potentially explosive atmospheres. Far more important than simply meeting a standard, product manufacturing, testing, installation and maintenance must be performed with the goal of ensuring unquestioned product safety.