三相電加熱管

        380伏三相(xiang)四(si)線電(dian)(dian)路中，任意兩根火(huo)線之間(jian)的電(dian)(dian)壓都是380伏，任意一(yi)根火(huo)線與零線之間(jian)都可(ke)以組成220伏。這個系統可(ke)以形成三種電(dian)(dian)源(yuan)(yuan)：即單(dan)相(xiang)220伏電(dian)(dian)源(yuan)(yuan)，單(dan)相(xiang)380伏電(dian)(dian)源(yuan)(yuan)，三相(xiang)380伏電(dian)(dian)源(yuan)(yuan)，第(di)(di) I 種家用比較多，第(di)(di)三種工(gong)廠里電(dian)(dian)機類用得(de)多，第(di)(di)二種用得(de)少，只(zhi)有交流電(dian)(dian)焊機經常用到單(dan)相(xiang)380伏電(dian)(dian)源(yuan)(yuan)。