increased security against the possibility of excessive temperatures and of the occurrence of arcs and sparks.
FPN: See ANSI/ISA-60079-7 (12.16.01)-2002, Electrical Apparatus for Use in Class I, Zone 1 Hazardous (Classi- fied) Locations, Type of Protection — Increased Safety "e"; and ANSI/UL 60079-7, Electrical Apparatus for Explosive Gas Atmospheres — Part 7: Increased Safety "e."
Intrinsic Safety "i." Type of protection where any spark or thermal effect is incapable of causing ignition of a mixture of flammable or combustible material in air under prescribed test conditions.
FPN No. 1: See ANSI/UL 913-1997, Intrinsically Safe Ap- paratus and Associated Apparatus for Use in Class I, II, and III, Hazardous Locations; ANSI/IS A-60079-11 (12.02.01)-2002, Electrical Apparatus for Use in Class I, Zones 0, 1 and 2 Hazardous (Classified) Locations — In- trinsic Safety "i"; and ANSI/UL 60079-11, Electrical Ap- paratus for Explosive Gas Atmospheres — Part II: Intrinsic Safety "/'."
FPN No. 2: Intrinsic safety is designated type of protection "ia" for use in Zone 0 locations. Intrinsic safety is designated
type of protection "ib" for use in Zone 1 locations.
FPN No. 3: Intrinsically safe associated apparatus, designated by [ia] or [ib], is connected to intrinsically safe apparatus ("ia" or "ib," respectively) but is located outside the hazardous (classified) location unless also protected by an- other type of protection (such as flameproof).
Oil Immersion "o." Type of protection where electrical equipment is immersed in a protective liquid in such a
way that an explosive atmosphere that may be above the liquid or outside the enclosure cannot be ignited.
FPN: See ANSWSA-60079-6 (12.26.01)-1998, Electrical Apparatus for Use in Class I, Zone I Hazardous (Classified) Locations, Type of Protection — Oil-Immersion "o"; and ANSI/UL
60079-6, Electrical Apparatus for Explosive Gas
Atmospheres — Part 6: Oil-Immersion "o."
Powder Filling "q." Type of protection where electrical parts capable of igniting an explosive atmosphere are fixed in position and completely surrounded by filling material (glass or quartz powder) to prevent the ignition of an external explosive atmosphere.
FPN: See ANSI/ISA-60079-5 (12.25.01)-1998, Electrical Apparatus for Use in Class I, Zone I Hazardous (Classified) Locations Type of Protection
— Powder Filling "q"; and ANSI/UL 60079-5,
Electrical Apparatus for Explosive Gas Atmospheres
— Part 5: Powder Filling "q. "
Pressurization "p." Type of protection for electrical equipment that uses the technique of guarding against the ingress of the external atmosphere, which may be explosive, into an enclosure by maintaining a protective gas therein at a pressure above that of the external atmosphere.
FPN: See ANSI/ISA-60079-2 (12.04.01)-2004,
Electrical Apparatus for Explosive Gas Atmospheres
— Part 2: Pressurized Enclosures "p"; and IEC
60079-13-1982, Electrical apparatus for explosive
gas atmospheres — Part 13: Construction and use of rooms or buildings protected by pressurization.
Type of Protection "n." Type of protection where electrical equipment, in normal operation, is not capable of igniting a surrounding explosive gas atmosphere and a fault capable of causing ignition is not likely to occur.
FPN: See ANSI/UL 60079-15-2002, Electrical
Apparatus for Explosive Gas Atmospheres — Part
15: Type of Protection "n"; and ANSI/ISA-60079-15
(12.12.02)-2003, Electrical Apparatus for Use in Class