Typical examples are water mains and gas pipes . equipotential bonding consists of main and supplementary equipotential bondings . it means the electrical connection linking various exposed conductive parts and extraneous conductive parts so as to achieve a substantially equal potential 至于等电位导体的作用,其实就是将各个外露非带电金属部分和非电气装置金属部分作电气性连接,使各部分的电位在颇大程度上相等。