Explosion-proof electrical equipment is categorized into six types based on their maximum surface temperatures: T1, T2, T3, T4, T5, thiab T6. These categories align with the ignition temperature groups for combustible gases.
Qhov kub thiab txias IEC / EN / GB 3836 | Qhov siab tshaj qhov kub ntawm cov khoom siv T [℃] | Lgnition kub ntawm cov khoom combustible [℃] |
---|---|---|
T1 | 450 | T 450 |
T2 | 300 | 450≥ T 300 |
T3 | 200 | 300≥ T 200 |
T4 | 135 | 200≥T > 135 |
T5 | 100 | 135≥T 100 |
T6 | 85 | 100≥T8 |
The term ‘maximum surface temperature’ denotes the highest temperature that can be reached on the surface or parts of the explosion-proof electrical equipment under both normal and the most adverse conditions deemed acceptable, with the potential to ignite surrounding explosive gas mixtures.
The guiding principle for temperature classification in explosion-proof electrical devices is as follows:
The peak surface kub generated by the device must not be capable of igniting adjacent combustible gases, and it should not exceed the ignition temperature of these gases. For safety ratings, T6 devices rank the highest, while T1 devices are at the lower end.
This demonstrates that for tawg materials with identical temperatures, it reflects the lower boundary of their ignition temperatures. Hloov pauv, rau Cov khoom siv hluav taws xob tawg, it denotes the upper limit of their maximum surface temperatures, showcasing a clear distinction in characteristics.
Given that explosion-proof electrical equipment utilized in explosive dust environments clearly states the device’s maximum surface temperature, tus “Electrical Equipment Design Code for Explosive Hazard Environments” no longer divides explosion-proof electrical equipment into temperature groups.