Selection principles for explosion-proof electrical equipment in explosive locations
Before selecting electrical equipment for use in explosive hazardous areas, the following should be clarified:
1. The category of the hazardous environment for explosion is whether it is an explosive gas environment or an explosive dust environment. The electrical equipment of different explosive mediaExplosion proof structural requirementsIt's different.
2. Explosion levels of explosive gas mixtures in the environment, namely IIA, IIB, and IIC. This is the polarization corresponding to the maximum test safety gap and minimum ignition current ratio of the equipment. Its level depends on the generation of explosive gasesZhongnuo TestingThe medium varies, such as propane belonging to IIA, ethylene belonging to IIB, acetylene and hydrogen belonging to IIC. As the maximum test safety clearance and minimum ignition current ratio of explosion-proof electrical equipment decrease step by step from IIA to IIC, the explosion-proof requirements gradually increase
3. The group or ignition temperature of explosive gas mixtures in the environment. This is flammableZhongnuo TestingThe minimum temperature at which a mixture of gas or vapor of a substance and air is ignited by a hot surface under specified conditions. As the ignition temperature decreases from group T1 to T6, the explosion-proof requirements for their electrical equipment gradually increase
4. Requirements for the selection of explosion-proof electrical equipment in the surrounding environment. When selecting explosion-proof electrical equipment, different environmental conditions such as chemical, mechanical, thermal, and fungal factors in the surrounding environment should be considered simultaneously.
After considering the above basic requirements, explosion-proof electrical products that meet the requirements can be selected. When some electrical equipment that must be arranged in explosive hazardous areas cannot meet the explosion-proof requirements of the site, positive pressure ventilation measures can be adopted to achieve itexplosion-proofThe requirements.
