三相電加熱管

        380伏(fu)(fu)三(san)相(xiang)四線電(dian)(dian)路中(zhong)，任(ren)意(yi)兩根火線之間(jian)的電(dian)(dian)壓都(dou)是380伏(fu)(fu)，任(ren)意(yi)一根火線與零線之間(jian)都(dou)可以組成220伏(fu)(fu)。這個系統可以形成三(san)種(zhong)電(dian)(dian)源(yuan)：即單相(xiang)220伏(fu)(fu)電(dian)(dian)源(yuan)，單相(xiang)380伏(fu)(fu)電(dian)(dian)源(yuan)，三(san)相(xiang)380伏(fu)(fu)電(dian)(dian)源(yuan)，第(di) I 種(zhong)家用(yong)(yong)比較多，第(di)三(san)種(zhong)工廠里電(dian)(dian)機(ji)類用(yong)(yong)得(de)多，第(di)二種(zhong)用(yong)(yong)得(de)少(shao)，只有(you)交流電(dian)(dian)焊機(ji)經常用(yong)(yong)到單相(xiang)380伏(fu)(fu)電(dian)(dian)源(yuan)。