The ignition temperature of an explosive gas mixture represents the maximum temperature at which it can be ignited.
Explosion-proof lighting equipment is categorized into groups T1 to T6, based on the maximum surface temperature of their outer casing. This classification ensures that the highest surface temperature of the explosion-proof lighting equipment in each group does not exceed the permissible temperature for that specific category. The relationship between temperature groups, the surface temperature of the equipment, and the ignition temperature of flammable gases or vapors is illustrated in the accompanying diagram.
| Temperature Class IEC/EN/GB3836 | Equipment Surface Temperature T [°C] | Yanıcı Maddelerin Tutuşma Sıcaklığı [°C] | Combustible Substances |
|---|---|---|---|
| T1 | 450 | T>450 | 46 types of hydrogen, acrylonitrile, etc |
| T2 | 300 | 450≥T>300 | 47 types of acetylene, ethylene, etc |
| T3 | 200 | 300≥T>200 | 36 types of gasoline, butyraldehyde, etc |
| T4 | 135 | 200≥T>135 | |
| T5 | 100 | 135≥T>100 | Karbon disülfür |
| T6 | 85 | 100≥T>85 | Etil nitrat |
It’s evident from this that the lower the surface temperature of the casing, the higher the safety requirements, making T6 the safest and T1 the riskiest in terms of potential ignition hazards.
