煤炭、石(shi)油、化學、紡織等工業在國(guo)民經濟中(zhong)(zhong)占很重要的(de)(de)地(di)位，這(zhe)些行業在生產過(guo)程(cheng)中(zhong)(zhong)會產生爆炸(zha)性(xing)氣(qi)體(ti)(ti)．蒸汽或爆炸(zha)性(xing)粉塵，這(zhe)種場所均(jun)稱為(wei)(wei)爆炸(zha)性(xing)危險(xian)場所。按國(guo)際IEC標準(zhun)和我國(guo)防(fang)爆標志(zhi)GB3836.1的(de)(de)規定，防(fang)爆電(dian)氣(qi)設(she)備分(fen)(fen)為(wei)(wei)二(er)類(lei)，即I類(lei)：煤礦用(yong)(yong)電(dian)氣(qi)設(she)備；II類(lei)：除煤礦外(wai)的(de)(de)其他(ta)爆炸(zha)性(xing)氣(qi)體(ti)(ti)環境用(yong)(yong)電(dian)氣(qi)設(she)備。除I類(lei)場所之外(wai)，II類(lei)場所按爆炸(zha)性(xing)物質出(chu)現的(de)(de)頻敏(min)程(cheng)度、持續時間又劃(hua)分(fen)(fen)為(wei)(wei)“0區(qu)”．“1區(qu)”、“2區(qu)”三(san)個等級，其中(zhong)(zhong)0區(qu)危險(xian)程(cheng)度最大。

防爆(bao)型(xing)(xing)(xing)(xing)(xing)式是為(wei)防止點(dian)燃周圍爆(bao)炸性混合物而對電氣設(she)備結構所采取特(te)定(ding)(ding)的安全措施，就我(wo)國(guo)現有(you)制定(ding)(ding)的強制性國(guo)家標準及近幾(ji)年來的技術狀況來說，其防爆(bao)型(xing)(xing)(xing)(xing)(xing)式有(you)：隔爆(bao)型(xing)(xing)(xing)(xing)(xing)“d”、增安型(xing)(xing)(xing)(xing)(xing)“e”、本質安全型(xing)(xing)(xing)(xing)(xing)“i”、正壓外殼(ke)型(xing)(xing)(xing)(xing)(xing)“p”、油浸(jin)型(xing)(xing)(xing)(xing)(xing)“o”、充(chong)砂型(xing)(xing)(xing)(xing)(xing)“q”、“n”型(xing)(xing)(xing)(xing)(xing)、澆封型(xing)(xing)(xing)(xing)(xing)“m”、特(te)殊型(xing)(xing)(xing)(xing)(xing)“s”、混合型(xing)(xing)(xing)(xing)(xing)（上(shang)述(shu)類型(xing)(xing)(xing)(xing)(xing)的復合，例d[ib]I）。