I have an AEx d IIB motor that is being installed in a Class 1, Division 1 location governed by NEC standards. This motor is additionally tagged for Class 1, Zone 1 on the CSA type certificate. I am having some trouble justifying this installation to the client - they want the motor tagged to specifically state "Class 1, Division 1." By NEC 500 standards, "explosion-proof" protection type is suitable for Class 1, Division 1 (the motor meets all of the other suitability requirements for Class 1, Division 1 with its group and temperature ratings).

My question is, does the AEx d designation satisfy the NEC requirement for "Explosion-Proof?" My understanding is that, although the "Ex d" protection type is defined as "Flame-proof" in IEC terminology, this protection type meets the NEC/UL definition of "Explosion-Proof" and the "A" in the marking certifies that the motor meets NEC's definition of "Explosion-Proof." Is this correct and, if so, what can I use to support this assertion?

Thank you very much in advance for any feedback you are able to provide.

Regards,

Peter