Class I electrical equipment does not adhere to a specific grading system.
For Class II electrical equipment, classification is determined by the type of flammable gas encountered. This equipment is further categorized into three explosion-proof types: IIA, IIБ, и IIC.
In environments utilizing Class I electrical equipment, where combustible gases other than метан are present, compliance with both Class I and Class II explosion-proof standards is mandatory.
Based on the specific properties of the експлозивен dust environment, Class III electrical equipment is segmented into three categories: IIIA, IIIB, and IIIC.