Class 1 Division 1 Ex Cert Process


New member
I am trying to make sure I understand the process with an NRTL when we go to test/certify our system.

I am working on a product for a C1D1 environment with "Explosion Proof" as the protection method. The system will have a UL listed explosion proof enclosure (modified by the manufacturer for conduit entry) with the appropriate metal conduit and fittings running to a UL listed explosion proof motor. The contents of the enclosure will all be UL Listed for ordinary locations. I'll also have the proper conduit running out of the C1D1 area for power.

Will the NRTL (test lab) require explosion tests as a system? Or because I used an explosion proof motor, enclosure, and conduit, will they not require explosion testing?


Staff member
There are several other manufacturer/fabricators here that are better suited to answer this question. While I have certainly required vendors to obtain NRTL certification, I don't tell them or the NRTL how to do it.