Standard for Purged and Pressurized Enclosures for Electrical Equipment
What is NFPA 496?
This standard provides information on the methods for purging and pressurizing electrical equipment enclosures to prevent ignition of a flammable atmosphere, whether introduced into the enclosure by a surrounding external atmosphere or by an internal source.
Official document scope
What does NFPA 496 address?
In addition to general requirements for pressurized enclosures, specific criteria are presented for Class I and Class II hazardous (classified) locations as specified by NFPA 70: National Electrical Code. NFPA 496 also includes chapters on pressurized control rooms; enclosures having an internal source of flammable gas or vapor; and analyzer rooms containing a source of flammable gas, vapor, or liquid.
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