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Install electrical equipment in Class I and Class II hazardous (classified) locations to prevent ignition of a flammable atmosphere. The 2017 edition of NFPA 496 helps you protect people, equipment, and facilities from potentially deadly hazards.

Work with the specialized knowledge you need to head off electrical equipment fires and explosions. Consistent with the 2017 edition of NFPA 70®: National Electrical Code® (NEC®), the 2017 edition of NFPA 496: Standard for Purged and Pressurized Enclosures for Electrical Equipment contains requirements for the design and operation of purged and pressurized electrical equipment enclosures.

This protection technique is used in Class I and Class II hazardous (classified) locations to reduce or prevent the presence of flammable materials within electrical equipment enclosures as specified by the NEC.

Electrical designers, installers, and AHJs reference NFPA 496 for vital requirements concerning:

• General Requirements for Pressurized Enclosures
• Pressurized Enclosures for Class I
• Pressurized Enclosures for Class II
• Pressurized Control Rooms
• Pressurized Enclosures Having Internal Source of Flammable Gas or Vapor
• Pressurized Analyzer Rooms Containing a Source of Flammable Gas, Vapor, or Liquid

To make the Standard more enforceable by states and jurisdictions, changes to the 2017 edition remove unenforceable language such as near, close to, and significant portion, because these terms cannot be quantified in the design or evaluation of an installation designed to NFPA 496 specifications.