Nevýbušné elektrické zariadenia sú rozdelené do šiestich typov na základe ich maximálnych povrchových teplôt: T1, T2, T3, T4, T5, a T6. Tieto kategórie sú v súlade so skupinami teplôt vznietenia pre horľavé plyny.
Úroveň teploty IEC/EN/GB 3836 | Najvyššia povrchová teplota zariadenia T [℃] | Teplota vznietenia horľavých látok [℃] |
---|---|---|
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≥T>8 |
Termín ‚maximálna povrchová teplota‘ 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 teplota 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 výbušný materials with identical temperatures, it reflects the lower boundary of their ignition temperatures. A naopak, pre elektrické zariadenia odolné voči výbuchu, 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, a „Electrical Equipment Design Code for Explosive Hazard Environments“ no longer divides explosion-proof electrical equipment into temperature groups.