Safety-related maintenance of explosionproof enclosures for Class I, hazardous locations

An overview of the National Electric Code requirements for enclosures for arcing devices in Class I locations is presented, along with the theory of explosionproof protection and the standards applicable to enclosures constructed with that type of protection. Three factors which bear on the satisfactory field performance of such equipment are summarized: installation, environment, and maintenance. Proper maintenance procedures applicable to explosionproof enclosures are suggested, and the results of improper maintenance are demonstrated through highlights of actual laboratory tests