Is "Ex" rating acceptable in the US?

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alo1

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NEC Article 505 indicates that equipment must be marked with the "AEx" rating for installation in a hazardous location and makes no mention of the "Ex" rating. However the NEC handbook indicates, under 500.9, that the "Ex" rating is based on the IEC standards and that "Ex" meets Both the European "EEx" standards and the American "AEx" standards.

Is the "Ex" rating acceptable in the US?

Is there a better explanation of this somewhere else?
 

rbalex

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An ?Ex? marking alone is not acceptable in US domestic applications. ?AEx? is a specific marking requirement of Section 505.9(C)(2)(3). FPN Figure 505.9(C)(2) Zone Equipment Marking also notes ?AEx? is the ?Symbol for equipment built to American Standards.?

I believe your Handbook reference is actually to Section 505.9. It simply states the IEC standard is a common reference standard for both ?EEx? and ?AEx;? however, the IEC standard is incomplete for both US domestic equipment and the European Common Market standards (commonly known as CENELEC).
 

alo1

Member
Thanks for the clarification.

rbalex said:
I believe your Handbook reference is actually to Section 505.9. It simply states the IEC standard is a common reference standard for both ?EEx? and ?AEx;? however, the IEC standard is incomplete for both US domestic equipment and the European Common Market standards (commonly known as CENELEC).

You are correct reference should have been to 505.9.
 
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