Intrinsically Safe Approval Certification for Class I and Class II

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dkleeus

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I work in an industry where at common hazardous location rating is Cl I, Div 1, Grp C & D, and Cl II, Div 1, Grp E, F & G. A vendor's product was marked when used with appropriate I.S. barriers met only Class 1, Div.1; Group C & D requirements. I inquired about the Class II, Div 1, Grp E, F & G approval certification. The vendors response was, "Qualification for a rating automatically qualifies the equipment for a lower class and group. For example: Class I equipment can be used in Class II and Class III applications with no restrictions. "

I do not believe this is correct so I'm looking for a confirmation and/or explanation. I have always looked for explicit Class and Div ratings for all apparatus that was not a simple device. I know that Div 1 approved devices may be used for Div 2. But I do not believe Class I automatically qualifies as Class II.

According to NEC 70, 500.8 (B) (1) "Equipment shall be identified not only for the class of location but also for the explosive, combustible, or ignitible properties of the specific gas, vapor, dust, or fibers/flyings that will be present."

Also, under 500.8 (C)(1), "Class. The marking shall specify the class(es) for which the equipment is suitable."

Based on my understanding, the vendor is incorrect. Please provide your opinion based on the code.
 
You are correct. The basic "Approval" rules are in Section 500.8, with 500.8(B) & (C) being more specific with regard to Class, Division, Group and Temperature Class requirements.
 
You are correct. The basic "Approval" rules are in Section 500.8, with 500.8(B) & (C) being more specific with regard to Class, Division, Group and Temperature Class requirements.

You might also review 504.10(B) and ask how the equipment was identified for Class II. And 502.5 specifically states explosionproof (Class I, Division 1) is NOT acceptable in Class II.
 
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I find this misunderstanding occurs too often from vendors or resellers. Manufacturers tend to be more conservative.

I found this passage when investigating this further; in NFPA 499, Recommended Practice... Dust, specifically states in article 4.1.5.4, "Equipment and wiring suitable for Class I, Division 1 locations are not required [for Class II locations] and might not be acceptable in Class II locations."

Thanks for replies. I believe misunderstanding is somewhat common and would like to see future code update include clarification similiar to what you mentioned in Section 502.
 
dkleeus said:
I find this misunderstanding occurs too often from vendors or resellers. Manufacturers tend to be more conservative.

I found this passage when investigating this further; in NFPA 499, Recommended Practice... Dust, specifically states in article 4.1.5.4, "Equipment and wiring suitable for Class I, Division 1 locations are not required [for Class II locations] and might not be acceptable in Class II locations."

Thanks for replies. I believe misunderstanding is somewhat common and would like to see future code update include clarification similiar to what you mentioned in Section 502.
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The 'misunderstanding' stems from lack oif understanding. Whereas it is true that a Div. 1 approved equipment is always allowed in Div. 2, the same is not true for Class. Salespeople have seldom the technical background necessary to understand the technical aspects of the stuff they selling, yet their financial success gets them ahead, and gets them into places where they don't belong, such as customer service and marketing and wind up making statements like this.
 
dkleeus said:
... I believe misunderstanding is somewhat common and would like to see future code update include clarification similiar to what you mentioned in Section 502.
Click to expand...
You have until the first Friday of 2014, to provide public input. Code Making Panel 14 (CMP14) would probably be open to the clarification.
 
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