Electrical explosion protection 1. Conductor Material Copper core insulated conductors or cables should be selected for wiring works in explosive dangerous environment. 2. Permissible carrying capacity of conductors The allowable current carrying capacity of insulated wires and cables shall not be less than 1.25 times of the rated current of fuse melt and 1.25 times of the setting current of automatic switch long delay overcurrent release. 3. Ways of laying lines 1) When the density of gas and vapor in the explosive environment is heavier than that of air, the electrical circuit should be laid at high altitude or buried underground.Cable bridge should be used for overhead laying; sand should be filled in the trench and effective drainage measures should be set up for cable trench laying. 2) When the density of gas and vapor in the explosion environment is lighter than that of air, the electric circuit is laid at a lower place or in a cable trench.When passing through holes in walls or floor slabs between different areas, the ducts, steel pipes or cables laying electrical lines should be clogged with non-combustible materials to prevent the flow of explosive mixtures or vapors along the ducts and cable pipes. 4. Connection of lines Connections of conductors or cables shall be fixed by bolts with loosening preventive measures, or by pressing, brazing and fusion welding, but shall not be wound.The connection between aluminium core and electrical equipment adopts reliable copper- aluminium transition joint and other measures. 5. Selection of Electrical Equipment The level and composition of explosion-proof electrical equipment shall not be lower than that of explosive gas mixture in the explosive gas environment.When mixture formed there by two is or an explosive more gas flammable substances, explosion-proof electrical equipment should be selected according to the higher dangerous level and group. 6. Grounding of live components Many electrical equipment can not be grounded in general, but in order to prevent live components from grounding sparks or dangerous temperatures and form a source of detonation, it is still necessary to be grounded in explosive dangerous places. It should also be noted that the main grounding lines should be located in different directions of the explosion dangerous area, and not less than two places should grounding body. be connected with the