Zone classification offers an alternative to classifying areas by division. The zone classification method includes 3 zones rather than 2 divisions, and also offers some alternative protection methods. Zone protection methods are different from protection methods used under division classification so some protection methods that are permitted in zone-classified areas are not permitted in areas classified by division. Overall, the wiring methods permitted in zone-classified areas are much the same as those permitted under division classification. Zone classification is recognized by the NEC only for Class I areas.

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