Class Compatibility - NEC 500.8.B.1

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FAIR RIVER

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Location
USA
Occupation
GC
Can someone please verify my statements here.

According to 2023 edition of NFPA 70 NEC 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"

This text clearly shows that a piece of electrical equipment (like a DC power supply) rated and marked solely for C1D2 is not compatible in a C2D2 environment. Even though the equipment in this scenario is explosion proof in a vapor environment, since it does not contain separate markings for C2D2 and related groups, it is not rated for a C2 environment.
 
This is completely separate from 500.8.B.2, which details division compatibility. Given the same class/group/temp, a D1 device can be used in a D2 environment. However, there is no similar interpretation for class coverage.
 
FAIR RIVER said:
Can someone please verify my statements here.

According to 2023 edition of NFPA 70 NEC 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"

This text clearly shows that a piece of electrical equipment (like a DC power supply) rated and marked solely for C1D2 is not compatible in a C2D2 environment. Even though the equipment in this scenario is explosion proof in a vapor environment, since it does not contain separate markings for C2D2 and related groups, it is not rated for a C2 environment.
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Yes, it must be marked for the Class, Division and group that it has been approved for. Equipment that does not contain any heat producing devices are typically marked for Class I and Class II. However such equipment it typically not cost effective in a Class II location.
One of the issues is that Class I equipment is permitted to have a higher external temperature than Class II equipment. The Class II temperature is also tested with a covering of the Class II material.
 
Thank you for the reply. I had a very, very frustrating conversation with a rep from an online retailer after being told equipment I purchased is rated for a C2 area. The HZ tablet is only marked for C1, and I have this sales guy on the phone telling me it is acceptable to use in a C2 area.

Its been a couple years since my last explosion proof industrial installation, but I'm not that big of a moron.
 
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