Explosion-proof electrical equipment, explosion-proof principle is: live parts of electrical equipment placed in a special case, the shell has the electrical components within the shell of the spark and arc and shell explosive mixture isolated from the role and can withstand entry The explosive mixture inside the shell is sparked by the electrical equipment inside the shell and the explosion pressure generated when the arc is detonated without damaging the shell; at the same time, it prevents explosion of explosives from the shell to the explosive mixture outside the shell and does not cause explosiveness outside the shell The mixture burns and explodes. This special shell called "flameproof enclosure." Electrical equipment with flameproof enclosures is called "flameproof electrical equipment." Explosion-proof electrical equipment has a good explosion-proof and explosion-proof performance, are widely used in underground coal mine and other explosive environment workplace. Flameproof electrical equipment marked "d". Flameproof electrical equipment in addition to the electrical part, the main structure, including the flameproof enclosure and some attached to the shell of the parts, such as gaskets, transparent parts, cable (wire) into the junction box and so on. According to explosion-proof electrical equipment explosion-proof principle, we know that explosion-proof enclosure should have explosion-proof and explosion-proof performance. The so-called explosion-proof shell is able to withstand explosive explosion explosion pressure generated by the shell, but does not produce their own damage and dangerous deformation capacity. The so-called explosion-proof performance is the explosion of the explosive mixture within the shell when the flame is emitted, does not cause explosive combustible mixture outside the shell. for Explosion-proof enclosure explosion-proof and explosion-proof performance, the flameproof enclosure shape, material, volume, structure, etc. have special requirements.