How to Choose the Explosion-Proof Level of Explosion-Proof Control Box

Explosion-proof control boxes are categorized into three levels: IIA, IIB, and IIC. The IIC level is marginally higher and more costly than IIB and IIA. Many customers are unsure about selecting the appropriate explosion-proof rating. Essentially, these ratings correspond to the presence of flammable and explosive gas mixtures in the environment. For instance, hydrogen is classified as IICT1, while carbon monoxide falls under IIAT1; therefore, its corresponding control box would be rated IIAT1, although it is typically categorized as IIB. For a comprehensive breakdown of ratings, please consult the “Introduction to Explosive Mixtures.”

Example:

A workshop needs to install five additional explosion-proof control boxes due to its ethanol production. The required rating for these boxes must meet or exceed IIAT2. Suitable ratings range from IIBT2-6 to IICT2-6, with IIBT4 being frequently utilized.