該變壓器在SG變壓器上面安裝一個外殼，起到的保護變壓器，美觀的同時也了變壓器的檔次，外殼的安裝方式有很多種，可以是就罩在變壓器上面的，也可以是整個變壓器放在殼子里面的，四周都是與外殼緣的，在外殼邊上開孔，方便接線的引入，并在外殼表面開一扇可以打開的門，方便接線，在外殼上安裝散熱風扇等等。

       SG（ZSG）系列三相干式變壓器廣泛應用于工礦企業、數控機床、加工中心、自動化控制設備，各類機械、發電廠、機場、高層建筑、地鐵等火要求較高的場所。作變換電壓，供照明電器設施，數控系統，動力電源、整流電源之用。該產品是戶內裝置，空氣自冷或風冷式。
 
         SG(ZSG) series three-phase dry-te transformers are widely used for industrial and mining enterprises，NC machine tools，processing centers，automatic controlling equipments，various kinds of machineries and places with stricter requirements for security and fireproofing，such as power plants，airports，high-rise buildings and subways etc.，serving as voltage transformer，power supply for lighting apparatus and facilities，numerical control systems，dynamical powers and rectifier powers.The products are indoor equipments，which are self-cooling by air or wind cooling.