Class I Divison 2 Enclosure Allowance

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STucker

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I have a compression skid that's to be outfitted with an enclosure that will contain only terminal blocks for the control wiring(not required to be explosion proof). The area will be CID2. I see in the NEC where it addresses whether or not an explosion proof box is required, but I don't see anywhere that specifies what type of enclosure should otherwise be used. This leads me to believe that the enclosure only needs to be suitable for its environment based on NEMA rating.

I'm seeing that there are enclosures on the market that are specifically listed for Class I Division 2, which makes me think that there may be a listing requirement that I'm not seeing.

Is there a requirement for the enclosure to be CID2 listed in my situation? If so, where can I find the reference for it?
 
rbalex

rbalex

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I am assuming you found Section 501.10(B)(4). It references the Sections that may require specific listing for Division 2, if the equipment is not already listed for Division 1.

You should also become familiar with Section 500.8. It is rather long, but, if you are going to do much Hazardous Location work, you need to know it too.

I'm curious as to whether the equipment you mentioned was specifically listed for Class I, Division 2 or if it was simply sales literature that said it was suitable (or some similar term) for Division 2. For the most part, with the exception of luminaires, if general purpose equipment is acceptable in Division 2, it doesn't need specific listing (or marking) for it. See Sections 500.8(B)(3) and 500.8(C)(6)(a). [But read all of Section 500.8 as well]
 
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petersonra

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rbalex said:
I am assuming you found Section 501.10(B)(4). It references the Sections that may require specific listing for Division 2, if the equipment is not already listed for Division 1.

You should also become familiar with Section 500.8. It is rather long, but, if you are going to do much Hazardous Location work, you need to know it too.

I'm curious as to whether the equipment you mentioned was specifically listed for Class I, Division 2 or if it was simply sales literature that said it was suitable (or some similar term) for Division 2. For the most part, with the exception of luminaires, if general purpose equipment is acceptable in Division 2, it doesn't need specific listing (or marking) for it. See Sections 500.8(B)(3) and 500.8(C)(6)(a). [But read all of Section 500.8 as well]
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I have seen the C1D2 thing with enclosure literature. never noticed whether it actually said it was listed that way or not.
 
rbalex

rbalex

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petersonra said:
I have seen the C1D2 thing with enclosure literature. never noticed whether it actually said it was listed that way or not.
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I don't know of any enclosure that is specifically listed for Division 2; there are plenty that are suitable though.
 
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STucker

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Ohio, US
rbalex said:
:thumbsup: also follow the Rittal "Approvals" link near the bottom of the second page
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I did see that beforehand. Is the UL certification all that's required for use in a Class I Div 2 location? That's kind of where the line is getting blurred for me here.

petersonra said:
look carefully at what it actually says.
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Ah yes, I didn't think much of this note since it's pretty much just pointing out this requirement from the NEC.

rbalex said:
It would appear Crouse-Hinds is up to their old tricks. Read the "certifications" notes; especially the dagger at the bottom of the page. These are simply Type 3S, 4 and 4X enclosures that need no special "certification" for Class I, Division 2.
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So they've "self certified" the product, I suppose.

The real question is where to draw the line on what's acceptable. Is ANY NEMA 4/4X enclosure acceptable for Class I Div 2 when you don't need to go explosion proof? It seems that 500.8(A) requires some kind of listing or labeling and Rittal makes no claims of HazLoc compliance for any of their enclosures(I contacted them to confirm). So when the AHJ comes to inspect, could I expect them to approve the Rittal enclosure, or is this a "play it safe" situation where it's not worth saving a buck for the risk?
 
rbalex

rbalex

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STucker said:
I did see that beforehand. Is the UL certification all that's required for use in a Class I Div 2 location? That's kind of where the line is getting blurred for me here.



Ah yes, I didn't think much of this note since it's pretty much just pointing out this requirement from the NEC.



So they've "self certified" the product, I suppose.

The real question is where to draw the line on what's acceptable. Is ANY NEMA 4/4X enclosure acceptable for Class I Div 2 when you don't need to go explosion proof? It seems that 500.8(A) requires some kind of listing or labeling and Rittal makes no claims of HazLoc compliance for any of their enclosures(I contacted them to confirm). So when the AHJ comes to inspect, could I expect them to approve the Rittal enclosure, or is this a "play it safe" situation where it's not worth saving a buck for the risk?
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There is no enclosure that needs specific listing for Class I, Division 2. Think of it this way: What unique feature would an enclosure need to be suitable for Class I, Division 2, that isn't already required for a general purpose enclosure that is suitable for the "nonhazardous" conditions of the environment? Some of the equipment it encloses may need specific Division 2 listing, they are mentioned in Sections 501.10(B)(4). [501.105(B)(1), 501.115(B)(1), and 501.150(B)(1)].

BTW, I was a major author for what became Section 500.8(A). Listing or labeling is only one means of establishing suitability. I often used Subsection 500.8(A)(3).
 
S

STucker

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Location
Ohio, US
rbalex said:
There is no enclosure that needs specific listing for Class I, Division 2. Think of it this way: What unique feature would an enclosure need to be suitable for Class I, Division 2, that isn't already required for a general purpose enclosure that is suitable for the "nonhazardous" conditions of the environment? Some of the equipment it encloses may need specific Division 2 listing, they are mentioned in Sections 501.10(B)(4). [501.105(B)(1), 501.115(B)(1), and 501.150(B)(1)].

BTW, I was a major author for what became Section 500.8(A). Listing or labeling is only one means of establishing suitability. I often used Subsection 500.8(A)(3).
Click to expand...

That does make practical sense. Thanks for the knowledgeable responses, gentlemen! :thumbsup:
 
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