Solid State Relay for Class I Division 2

[not_a_EE]

I have a general purpose enclosure with all components rated as Class I Division 2 inside the enclosure. The enclosure is located in a Class I Division 2 location. The only part I'm struggling with is finding a solid state relay that is rated for Class I Division 2. Am I reading this correctly that I can use an SSR that isn't certified for Class I Division 2 if I can somehow show that the surface temperature doesn't exceed the autoignition temperature (which is super high in my application)?

501.115(B)(1)(4): The device is a solid state, switching control without contacts, where the surface temperature does not exceed 80 percent of the autoignition temperature in degrees Celsius of the gas or vapor involved.

 

[rbalex]

Yes, except that it can't exceed 80% of the autoignition temperature in degrees Celsius of the gas or vapor involved.

Also see Section 500.8(C)(6)(a) and be certain you can document the surface temperature.

 

[not_a_EE]

Maybe a related question. In the enclosure, with everything rated Class I Division 2, how is it possible to have a CID2 rated power supply (120VAC to 24VDC) with screw terminals and still comply with 501.25? I feel like I'm misunderstanding something in the code here. Is the fact that it's rated for the location preempt 501.25 per the reference to 500.7?

501.25 Uninsulated Exposed Parts, Class I, Divisions 1 and 2. There shall be no uninsulated exposed parts, such as electrical conductors, buses, terminals, or components, that operate at more than 30 volts (15 volts in wet locations). These parts shall additionally be protected by a protection technique according to 500.7(E), (F), or (G) that is suitable for the location.

 

[rbalex]

Exposed (as applied to wiring methods) is a defined term in Article 100. The terminals you have described aren’t exposed.