Zone Classifications
Equipment that is used in hazardous areas is classified into zones, depending on the potential of an explosion under normal operating conditions.
The table below is a guide to zone classification of hazardous areas. B&R Enclosures do not classify areas for customers, it is the responsibility of the installer or end user to know which zone their area falls within.
It is recommended a qualified person is engaged to complete a risk analysis and classify the area in accordance with standard IEC 60079-14.
The hazardous areas are classified in the table below according to IEC 60079-10-1 and IEC 61241-10-2. The IEC Standard is the international standard and local standard must be used where applicable.
Gases and Vapours
Zone 0 Ga
An area in which an explosive gas-air mixture is continuously present or present for long periods.
Zone 1 Gb
Area in which an explosive gas-air mixture is likely to occur for short periods in normal operation.
Zone 2 Gc
Area in which an explosive gas-air mixture is not likely to occur and if it occurs it will only exist for a very short time due to an abnormal condition.
Dust
Zone 20 Da
An area in which an explosive dust-air mixture is continuously present or present for long periods.
Zone 21 Db
Combustible or conductive dusts are present and is likely to occur for short periods in normal operation.
Zone 22 Dc
Area in which an explosive dust mixture is not likely to occur and if it occurs it will only exist for a very short time due to an abnormal condition.
