In the field of explosion-proof equipment, the safety is significantly determined by the temperature classification of the device. The T6 classification, indicating the “maximum surface temperature,” represents the safest category within this range. This classification ensures that the surface temperature of the equipment is low enough to prevent igniting flammable gases, even those with a low ignition point. Conversely, T1, with the highest allowed surface temperature, poses the greatest risk in explosive environments.
| Temperature Classification for Electrical Equipment | Maximum Permissible Surface Temperature of Electrical Equipment (°C) | Gas/Vapor Ignition Temperature (°C) | Applicable Equipment Temperature Class |
|---|---|---|---|
| T1 | 450 | ＞450 | T1~T6 |
| T2 | 300 | ＞300 | T2~T6 |
| T3 | 200 | ＞200 | T3~T6 |
| T4 | 135 | ＞135 | T4~T6 |
| T5 | 100 | ＞100 | T5~T6 |
| T6 | 85 | ＞85 | T6 |
In explosion-proof equipment, the primary concern isn’t an internal component explosion, but rather the restriction of energy released from damaged internal components to prevent igniting gases in explosive atmospheres. As per the “Design Specifications for Electrical Installations in Explosive and Fire Hazardous Environments”, the T6 level stands as the safest classification. Devices with T6 classification are effective in preventing explosions, especially in environments with low ignition point combustible gases, not to mention those with higher ignition points.
