Explosion-proof classification
Explosion-proof grades are divided into three categories
Category I: Electrical equipment underground in coal mines;
Class II: All other electrical equipment for explosive gas environments except coal mines and underground mines.
Class Ⅱ can be divided into ⅡA, ⅡB, and ⅡC. Equipment marked with ⅡB can be applied to the use conditions of ⅡA equipment; ⅡC can be applied to the use conditions of ⅡA and ⅡB.
Class III: Electrical equipment in explosive dust environment other than coal mines.
Class ⅢA: flammable fly floc; Class ⅢB: non-conductive dust; Class ⅢC: conductive dust.
Maximum surface temperature: The maximum temperature reached by any part of the electrical equipment that may cause the surrounding explosive environment to ignite when the electrical equipment is working under the most unfavorable operating conditions within the specified range. The maximum surface temperature should be lower than the combustible temperature.
