三相電加熱管

        380伏(fu)(fu)三相(xiang)四(si)線電(dian)(dian)(dian)路(lu)中，任意(yi)兩(liang)根火(huo)線之(zhi)間(jian)的(de)電(dian)(dian)(dian)壓都是380伏(fu)(fu)，任意(yi)一(yi)根火(huo)線與(yu)零線之(zhi)間(jian)都可以組(zu)成220伏(fu)(fu)。這(zhe)個系統可以形成三種電(dian)(dian)(dian)源：即單(dan)(dan)相(xiang)220伏(fu)(fu)電(dian)(dian)(dian)源，單(dan)(dan)相(xiang)380伏(fu)(fu)電(dian)(dian)(dian)源，三相(xiang)380伏(fu)(fu)電(dian)(dian)(dian)源，第(di) I 種家用比較多，第(di)三種工廠里電(dian)(dian)(dian)機類用得(de)多，第(di)二種用得(de)少，只(zhi)有(you)交流電(dian)(dian)(dian)焊機經常用到(dao)單(dan)(dan)相(xiang)380伏(fu)(fu)電(dian)(dian)(dian)源。