Epoxy embedded poles, or called vacuum interrupters with epoxy resin, is made by casting vacuum interrupters, main circuit conduct and mounting parts with epoxy into an integral part. The vacuum interrupters, however, should be enveloped well with a slight fold of silicon rubber jacket before that process.

From the development of insulations on breakers, it can be divided into three generations: air, composite and solid insulation and so-called solid insulation means epoxy embedded poles, which might represent the great advancement of insulation on vacuum breakers. Since the epoxy can be used to replace the insulating and mechanical supports, the breakers therefore become compact and simple and are able to service under humid and dusty conditions. The embedded poles of Shuguang are all made by Automatic Pressure Gelation process(APG process) and have many features such as integrated mold production, free maintenance, compact, stable and reliable dielectric strength and etc.. When the external insulations of miniature chambers in air condition fail to fulfill the requests of specifications, embedded poles are therefore introduced and now become one of the most applicable ways in the field of medium voltage breakers either at home or abroad.