三相電加熱管

        380伏(fu)三相(xiang)四線電(dian)(dian)(dian)路中，任意兩根(gen)(gen)火(huo)線之間(jian)的電(dian)(dian)(dian)壓都(dou)是380伏(fu)，任意一(yi)根(gen)(gen)火(huo)線與零線之間(jian)都(dou)可以組(zu)成220伏(fu)。這個系統可以形成三種(zhong)電(dian)(dian)(dian)源：即單(dan)(dan)相(xiang)220伏(fu)電(dian)(dian)(dian)源，單(dan)(dan)相(xiang)380伏(fu)電(dian)(dian)(dian)源，三相(xiang)380伏(fu)電(dian)(dian)(dian)源，第 I 種(zhong)家用比較多，第三種(zhong)工廠(chang)里電(dian)(dian)(dian)機類用得(de)多，第二種(zhong)用得(de)少，只有交流電(dian)(dian)(dian)焊機經常用到(dao)單(dan)(dan)相(xiang)380伏(fu)電(dian)(dian)(dian)源。