Hermetically sealed - who decides??

[twoplates]

I routinely build enclosures for class i, div 2 environments using components with rating agency approvals (marks) indicating they are suitable for Class i, div 2 areas. I also use terminal blocks for low voltage wiring I/O (12 vdc, 24 vdc, etc). I have a current project which requires a dc/dc step down conversion. I am contemplating using what appears to be a fully encapuslated (therefore hermetically sealed based on my understanding of the term) in this panel build. Only the I/O terminals are exposed, otherwise no possible air ingress as best i can tell. I have sourced several of these converters but none carry any mark indicating they are suitable for a hazardous area. Can I make the determination for myself that this is an acceptable device for this application giving the definition in the code but absent the marking?

 

[don_resqcapt19]

Hermetically sealed only applies to devices with arc producing components such as contacts. I would expect the dc/dc converter is 100% electronic with no arc producing devices.

 

[rbalex]

The "Code" definition is:

Sealed, Hermetically. (Hermetically Sealed):

Sealed against the entrance of an external atmosphere, such that the seal is made by fusion of metal to metal, ceramic to metal, or glass to metal. (CMP-14)

Informational Note: See ANSI/UL 121201, Nonincendive Electrical Equipment for Use in Class I and II, Division 2 and Class III, Divisions 1 and 2 Hazardous (Classified) Locations, for additional information.​

It says nothing about arc producing components. (So why are we sealing it?) I'll be the first to admit it's confusing. The next question is as the OP asks: Who Decides. I agree with Don it's reasonable to assume the converter is probably safe, but I'd expect and AHJ would still like to see the whole "assembly" identified.

 

[twoplates]

Thanks gentlemen, very helpful insight and information....