Explosion Proof Motors

Often, but not always, class 1 listed items will also be listed for class 2 applications from my observations. Might depend on what testing and evaluations were done when listing the item I guess. Seems if you were going to make a hazardous location item though you would likely have it listed for every category it qualifies for.

Anything listed for class 1 locations should be suitable to keep grain dust out, so what may factor in is how much dust can accumulate on the surface before there is risk of being ignited should the surface temp rise because of the layer of insulating dust.

Motor overloading probably isn't as big of a potential ignition factor here as say a failing bearing might be.

Just my thoughts. I don't have extensive experience in hazardous locations.
 
Easy to point out electrical items as possible problems, hope whoever is requiring this also takes mechanical items into consideration. A bad bearing in the driven equipment can be just as much of a potential ignition risk as a bad bearing in a motor. Motors with no switching/arcing Like start capacitor switches on single phase motors components aren't really much of an ignition hazard, surface operating temperatures is the bigger risk. However they are usually low enough until something begins to fail.
 
richard.jackson said:
I I have a class 2 group g motor and I am being told to replace it with a class 1 group d motor, is this a safe or allowable action?
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The key application is Section 502.5. The next consideration is the Division and Section 502.125 (A) or (B) as applicable. If it is Division 2, in most cases, it isn’t even necessary to be specifically identified for Class II.

In any case, an explosionproof motor is not required or acceptable unless it is also identified (not necessarily listed or labeled) for Class II.
 
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