IEC standards for Explosive Atmospheres
Selection of Devices According to Zones
Selection of the device depending on the ignition temperature of the gas / vapour.
It is utmost important to select a device that will not heat up so that it's maximum surface temperature will not reach the ignition temperature of any gas or vapour present around it. In case the electrical device does not support temperature range of ambience, it is ideal to use an electrical device within surrounding temperature range of -20°C to +40°C.
Selection of device depending on grouping of devices.
The grouping of gases and vapors are arranged in the categories of Group 1 and Group 2. The 1st group is related to air containing firedamp (a combination of gases, most of them being methane which is regularly discovered underground in mines). The 2nd group is expected to be used in all other places with possibly explosive environments. Group 2 electrical devices with types of protection ‘d’ and ‘i’ are segregated into device group 2A, 2B or 2C. Electrical devices with type of protection ‘n’ may also likewise be sub-divided on the basis of certain devices or components that they contain.
Construction standards of the device..
- IEC/EN 60079-0 - General Requirements
- IEC/EN 60079-1 - Flameproof Enclosure ‘d’
- IEC/EN 60079-2 - Pressurization ‘p’
- IEC/EN 60079-5 - Powder Filling ‘q’
- IEC/EN 60079-6 - Oil Immersion ‘o’
- IEC/EN 60079-7 - Improved Safety ‘e’
- IEC/EN 60079-11 - Intrinsically Safe ‘I’
- IEC/EN 60079-15 - Electrical Device type ‘n’
- IEC/EN 60079-18 - Encapsulation ‘m’
- IEC/EN 60079-28 - Protection of devices and transmission systems using optical radiation
- IEC/EN 60079-31 – Protection from dust by enclosure ‘t’
Subdivision based on the characteristics of the existing gases