Dust explosion-proof electric hoists are classified into three explosion-proof grades: IIA, IIB, and IIC. They are suitable for environments where combustible gases or vapors mix with air, categorized into temperature groups T1 to T4.
Condition Category | Gas Classification | Representative gases | Minimum Ignition Spark Energy |
---|---|---|---|
Under The Mine | I | Methane | 0.280mJ |
Factories Outside The Mine | IIA | Propane | 0.180mJ |
IIB | Ethylene | 0.060mJ | |
IIC | Hydrogen | 0.019mJ |
These electric hoists are further divided into Class B and Class C types, typically utilized in Zones 1 and 2. The applicable temperature range for these hoists spans from T1 to T6, with T6 being the safest in terms of explosion-proof safety.