Division vs Zone

[Henas]

I have a question regarding the use of Class 1 Zone 1 equipment.

Is increased safety "Ex e" allowed according to NEC? Or is the protection techniques allowed, the same as with Division?

 

[rbalex]

I have a question regarding the use of Class 1 Zone 1 equipment.

Is increased safety "Ex e" allowed according to NEC? Or is the protection techniques allowed, the same as with Division?

This is a bit difficult to explain to the uninitiated. If possible, you should get a copy of the NEC for reference. An online version is available here. It isn't too user friendly.

Technically, "Ex e" is not acceptable at all - even in NEC Zones. In fact, the "Ex" mark is not recognized in the NEC; it must be marked "AEx". This is part of the requirements for NEC Zones in Section 505.9(C)(2). It means it has been certified by a Nationally Recognized Testing Laboratory (NRTL) to a US recognized American National Safety Standard.

Once that hurdle is met, the "AEx e" protection technique only recognized in Class I, Division 2. See Section 501.5.