三相電加熱管

        380伏三相(xiang)四線(xian)電(dian)(dian)(dian)路(lu)中，任意兩(liang)根(gen)火線(xian)之間(jian)的電(dian)(dian)(dian)壓都是(shi)380伏，任意一根(gen)火線(xian)與零線(xian)之間(jian)都可以(yi)組成(cheng)220伏。這(zhe)個系(xi)統可以(yi)形成(cheng)三種電(dian)(dian)(dian)源：即單相(xiang)220伏電(dian)(dian)(dian)源，單相(xiang)380伏電(dian)(dian)(dian)源，三相(xiang)380伏電(dian)(dian)(dian)源，第(di) I 種家用比較多，第(di)三種工廠里(li)電(dian)(dian)(dian)機類(lei)用得多，第(di)二種用得少，只有(you)交(jiao)流(liu)電(dian)(dian)(dian)焊(han)機經常(chang)用到單相(xiang)380伏電(dian)(dian)(dian)源。