Definition of explosion-proof level
The classification of explosion-proof electrical equipment is based on the type of equipment used, the temperature group of the explosive gas mixture, and the type of explosion-proof electrical equipment.
Explosion-proof electrical equipment is divided into two categories: Category I is electrical equipment for underground coal mines; II is electrical equipment used in places other than mines, and is distinguished according to the large test safety clearance (MESG) or small ignition current (MICR). The equipment is divided into three categories: IIA, IIB and IIC.
The above four categories are mainly based on the small spark energy that may be detonated under different working conditions. China and Europe and most countries and regions in the world will divide explosive gases into these four hazard levels. The specific differences are as follows:
Group comparison
Secondly, according to the difference in ignition temperature of explosive gas mixtures, the groups are divided into T1, T2, T3, T4, T5, and T6. The ignition temperature is represented by t (℃), and the ignition temperature of each group is :
T1 is: 450 ℃
T2 is: 300 ℃
T3 is: 200 ℃
T4 is: 135 ℃
T5 is: 100 ℃
T6: 85 ℃
Again, for different uses, the explosion-proof types of explosion-proof electrical appliances are different. The types include: 1. Explosion-proof type, marked d;
2. Increased safety type, marked e;
3. Positive pressure type, the mark is P;
4. Intrinsically safe type, the symbol is i,
5. Oil-filled type, the mark is o;
6. Sand filling type, the symbol is q;
7. No spark type, the mark is n;
8. Pouring seal type, the mark is m;
9. Airtight type, the symbol is h.
Examples
The explosion-proof mark is dIIBT4, which represents: the type of explosion-proof electrical products is flameproof. It is a class IIB (category) used in a class II place, and the ignition temperature of explosive gases is T4.
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