三相電加熱管

        380伏三相(xiang)四線電(dian)(dian)(dian)(dian)路中(zhong)，任(ren)意(yi)兩根(gen)火(huo)線之間(jian)的電(dian)(dian)(dian)(dian)壓(ya)都是380伏，任(ren)意(yi)一根(gen)火(huo)線與零線之間(jian)都可以(yi)組成220伏。這個系統可以(yi)形(xing)成三種(zhong)電(dian)(dian)(dian)(dian)源(yuan)：即單相(xiang)220伏電(dian)(dian)(dian)(dian)源(yuan)，單相(xiang)380伏電(dian)(dian)(dian)(dian)源(yuan)，三相(xiang)380伏電(dian)(dian)(dian)(dian)源(yuan)，第 I 種(zhong)家用(yong)比較多(duo)，第三種(zhong)工廠里(li)電(dian)(dian)(dian)(dian)機(ji)(ji)類用(yong)得(de)多(duo)，第二種(zhong)用(yong)得(de)少(shao)，只有交流電(dian)(dian)(dian)(dian)焊機(ji)(ji)經常(chang)用(yong)到單相(xiang)380伏電(dian)(dian)(dian)(dian)源(yuan)。