三相電加熱管

        380伏(fu)(fu)(fu)(fu)(fu)三相四(si)線(xian)電(dian)(dian)(dian)路中，任意兩根(gen)火(huo)線(xian)之間的電(dian)(dian)(dian)壓(ya)都是380伏(fu)(fu)(fu)(fu)(fu)，任意一根(gen)火(huo)線(xian)與零線(xian)之間都可以組成(cheng)220伏(fu)(fu)(fu)(fu)(fu)。這(zhe)個系統可以形成(cheng)三種(zhong)(zhong)電(dian)(dian)(dian)源(yuan)(yuan)：即單(dan)相220伏(fu)(fu)(fu)(fu)(fu)電(dian)(dian)(dian)源(yuan)(yuan)，單(dan)相380伏(fu)(fu)(fu)(fu)(fu)電(dian)(dian)(dian)源(yuan)(yuan)，三相380伏(fu)(fu)(fu)(fu)(fu)電(dian)(dian)(dian)源(yuan)(yuan)，第 I 種(zhong)(zhong)家用(yong)比較多(duo)，第三種(zhong)(zhong)工(gong)廠里電(dian)(dian)(dian)機類用(yong)得(de)多(duo)，第二種(zhong)(zhong)用(yong)得(de)少(shao)，只有(you)交流(liu)電(dian)(dian)(dian)焊機經常用(yong)到(dao)單(dan)相380伏(fu)(fu)(fu)(fu)(fu)電(dian)(dian)(dian)源(yuan)(yuan)。