Equipment Assemblies for Explosive Atmospheres

This article will discuss the requirements for evaluating an equipment assembly for evidence of compliance to applicable standards, for the purpose of obtaining certification or a listing from a certification body. This would allow the equipment to be marked as suitable for use in explosive atmospheres. Historically there was little guidance for evaluating ex equipment assemblies and as such evaluations could be complicated and costly. In 2017, a technical specification, IEC TS 60079-46, was published for the evaluation of equipment assemblies for explosive environments. In 2018, Canada adopted the IEC TS 60079-46 with Canadian deviations, as CAN/CSA C22.2 No. 60079-46. The USA is in the process of adopting a version of IEC TS 60079-46 with national deviations. This is a step forward in being able to approve assemblies so that any additional investigation in the field is minimized or eliminated.