What is the classification of hazardous area?

Zone 1: An area in which an explosive gas atmosphere is likely to occur in normal operation; Zone 2: An area in which an explosive gas atmosphere is not likely to occur in normal operation and, if it occurs, will only exist for a short time.

Does IIC cover IIB?

Gases in Gas Group IIA require a higher ignition energy than gas groups IIB. Gases in Gas Group IIC require the lowest ignition energy to ignite. As the table below shows, there are only 5 gases in group IIC. Certifying your product for gasgroup IIA & IIB is usually sufficient to cover 98% of the market.

What’s the difference between Group II and group IIB?

Group II is subdivided into IIC, IIB, and IIA, according to the nature of the gas or vapor: Group IIC is equivalent to a combination of Class I, Group A and Class I, Group B in the NEC system. Group IIB is equivalent to Class I, Group C in the NEC system.

Are there any gases in Group IIB or IIC?

Gas The are no listed gases in Group IIB and Group IIC includes only a small number of (the most easily ignited) gases 2 Most petrochemical applications are designated IIB or occasionally IIB + Hydrogen. Certification for IIB + Hydrogen is can be easier to achieve than a full IIC particularly for Ex d flammable protected equipement.

How to determine hazardous area classification for electrical systems?

Identify the specific “group” for the hazardous substance (Group A through Group G). Determine the degree of the classification (Division 1 or Division 2). Determine the extent of the classified locations.

How is Group II classified in the NEC system?

Group II covers all other flammable gases. Group II is subdivided into IIC, IIB, and IIA, according to the nature of the gas or vapor: Group IIC is equivalent to a combination of Class I, Group A and Class I, Group B in the NEC system. Group IIB is equivalent to Class I, Group C in the NEC system.