Hazardous Area Classification

check this out

http://en.wikipedia.org/wiki/Electrical_equipment_in_hazardous_areas

You did not state what part of the globe you are from therefore, here is another link which is from US jurisdiction: http://www.engineeringtoolbox.com/hazardous-areas-classification-d_345.html

Good Luck!

Thanks for your replies. I am in India and we normally work on IEC standards.

If you would like to do the area classification drawing, use API RP 500 for NEC area classification (Division 1 and Division 2) and API RP 505 for IEC area classification (Zone 0, Zone 1 and Zone 2).

You can buy it from here: http://www.techstreet.com/cgi-bin/results

If you would like to know the definitions of the area classifications, use IEC 60079 (Zone 0, Zone 1 and Zone 2) or NEC article 500 (Division 1 and Division 2) and NEC article 505 (Zone 0, Zone 1 and Zone 2).

See this link for buying other standards: http://cr4.globalspec.com/thread/51102

- MS

In refineries & petrochemicals industry,according to IEC there are 3 classifications for the area containing the flammable substances(gas,vapour,volatile liquids) in the atmosphere.

1)Zone 2:The chances of presence of hazardous materials is <10 hrs per annum.(hazardous material not likely to appear in normal operations).

2)Zone 1:The chances of presence of hazardous materials is between 10 to 1000 hrs per annum.

3)Zone 0:The chances of presence of hazardous materials is >1000 hrs per annum.

Its clear than the ZONE 0 is the most dangerous zone.For dusts its classified as ZONE 22,zone 21,zone 20 respectively.

Giri, Thanks for the information. Based on which standard you have given the area classification based on the hours? I remember one Dutch practice guide line document NPR 7910-1 gives this type of classification of hazarous area. Are you referring to some thing similar?

Sorry....It was IEC 79.10..............you can get many information of them in internet.........