LumaSense Technologies M8100SM-EXP - Manual (Page 58)

E 2 T QUASAR Flare Monitors Operation Manual Appendix B: Area Classification/Protection
Concepts 58
Contains the explosion, prevents flame propagation
Class 1, Division 1, Groups C and D; T4A
Class 1, Division 2, Groups A,B,C&D; T4A
Enclosure Type 4x
Defined by Article 500 NEC; Class, Division and Gas Groups:
Location Classification I (Class 1): flammable gases or vapors
Hazard probability Division 1 (Div 1): Intermittent or High probability of explosive atmosphere
present during normal operation
Division 2 (Div2): abnormal conditions, low probability during operation
Gas/Vapor Groups: A through D
T4A:
Temperature code: maximum surface temperature will not exceed 2488 °F (1208 °C).
Enclosure Type 4X:
Indoor/Outdoor type; Protection from: corrosion, windblown dust and rain, splashing water,
hose directed water, external formation of ice.
Where a given location is classified as hazardous, it should not be difficult to determine in which
of the three classes it be-longs. Common sense and good judgment must prevail in classifying an
area that is likely to become hazardous and in determining those portions of the premises to be
classed Division 1 or Division 2.
Protection Concepts, Article 500
Sections 500-5, 500-6, and 500-7 recognize three classes of hazardous (classified) locations
having varying degrees of hazard, and each class is subdivided into two divisions. The
requirements for Division 1 of each class are more stringent than those for Division 2.
The hazards of the three classes are defined as follows:
Class I, flammable gases or vapors;
Class II, combustible dust;
Class III, combustible fibers or filings.
500-5. Class I Locations. Class I locations are those in which flammable gases or vapors are or
may be present in the air in quantities sufficient to produce explosive or ignitable mixtures.
Class I locations shall include those specified in (a) and (b) below.
(a) Class I, Division 1. A Class I, Division 1 location is a location: (1) in which ignitable
concentrations of flammable gases or vapors can exist under normal operating conditions; or (2)
in which ignitable concentrations of such gases or vapors may exist frequently because of repair
or maintenance operations or because of leakage; or (3) in which breakdown or faulty
operation of equipment or processes might release ignitable concentrations of flammable gases
or vapors, and might also cause simultaneous failure of electric equipment.
(FPN): This classification usually includes locations where volatile flammable liquids or liquefied
flammable gases are transferred from one container to another; interiors of spray booths and