NFPA 496:2021
Superseded
A superseded Standard is one, which is fully replaced by another Standard, which is a new edition of the same Standard.
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Standard for Purged and Pressurized Enclosures for Electrical Equipment
Hardcopy
31-05-2023
English
14-08-2021
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Chapter 1 Administration 1.1 Scope. 1.2 Purpose. 1.3 Application. 1.4 Equivalency. 1.5 Units of Measurement. 1.6 Mandatory Rules, Permissive Rules, and Explanatory Material. Chapter 2 Referenced Publications 2.1 General. 2.2 NFPA Publications. 2.3 Other Publications. 2.4 References for Extracts in Mandatory Sections. Chapter 3 Definitions 3.1 General. 3.2 NFPA Official Definitions. 3.3 General Definitions. 3.4 NEC Extracted Definitions. Chapter 4 General Requirements for Pressurized Enclosures 4.1 Applicability. 4.2 Suitability of Identified Equipment. 4.3 Enclosure. 4.4 Pressurizing System. 4.5 Protective Gas System. 4.6 Determination of Temperature Marking. 4.7 Ventilated Equipment. 4.8 Power Switching Equipment. 4.9 Type Z Pressurizing. 4.10 Type Y Pressurizing. 4.11 Type X Pressurizing. 4.12 Markings. Chapter 5 Pressurized Enclosures for ClassI, or Zone 1, or Zone 2 5.1 Applicability. 5.2 General Requirements. 5.3 Markings. 5.4 Additional Requirements for Type Y or Type Z Pressurizing. 5.5 Additional Requirements for Type X Pressurizing. Chapter 6 Pressurized Enclosures for ClassII 6.1 Applicability. 6.2 General Requirements. 6.3 Markings. 6.4 Marking Information. 6.5 Additional Requirements for Type X Pressurizing. 6.6 Additional Requirements for Ventilated Equipment. Chapter 7 Pressurized Control Rooms 7.1 Applicability. 7.2 Protective Gas. 7.3 Considerations Relating to Positive Pressure Ventilation. 7.4 Requirements for Positive Pressure Air Systems. Chapter 8 Pressurized Enclosures Having an Internal Source of Flammable Gas or Vapor 8.1 Applicability. 8.2 General Requirements. 8.3 Specific Requirements. Chapter 9 Pressurized Analyzer Rooms Containing a Source of Flammable Gas, Vapor, or Liquid 9.1 Applicability. 9.2 General. 9.3 Specific Requirements. Annex A Explanatory Material Annex B Informational References
This standard applies to purging and pressurizing for the following: (1) Electrical equipment located in areas classified as hazardous by Article 500 or Article 505 of NFPA 70 (2) Electrical equipment containing sources of flammable vapors or gases and located in either classified or unclassified areas (3) Control rooms or buildings located in areas classified as hazardous by Article 500 or Article 505 of NFPA 70 (4) Analyzer rooms containing sources of flammable vapors or gases and located in areas classified as hazardous by Article 500 or Article 505 of NFPA 70 1.1.2* This standard does not apply to electrical equipment located in: (1) Areas classified as Class I, Zone 0 (2) Areas classified as Class III (3) Areas where flammable liquids may be splashed or spilled on the electrical equipment .
| DocumentType |
Standard
|
| Pages |
31
|
| PublisherName |
National Fire Protection Association
|
| Status |
Superseded
|
| SupersededBy | |
| Supersedes |
| NFPA 70B:2023 | Standard for Electrical Equipment Maintenance |
| NFPA 59A:2023 | Standard for the Production, Storage, and Handling of Liquefied Natural Gas (LNG) |
| NFPA 35:2021 | Standard for the Manufacture of Organic Coatings |
| NFPA 53 : 2021 | Recommended Practice on Materials, Equipment, and Systems Used in Oxygen-Enriched Atmospheres |
| NFPA 55:2023 | Compressed Gases and Cryogenic Fluids Code |
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