三相電加熱管

        380伏(fu)三相(xiang)四線(xian)電(dian)(dian)路中，任意兩(liang)根火線(xian)之(zhi)間的電(dian)(dian)壓都是380伏(fu)，任意一根火線(xian)與零線(xian)之(zhi)間都可以組成220伏(fu)。這個系統(tong)可以形成三種(zhong)電(dian)(dian)源(yuan)：即單(dan)相(xiang)220伏(fu)電(dian)(dian)源(yuan)，單(dan)相(xiang)380伏(fu)電(dian)(dian)源(yuan)，三相(xiang)380伏(fu)電(dian)(dian)源(yuan)，第(di)(di) I 種(zhong)家用(yong)(yong)比(bi)較多，第(di)(di)三種(zhong)工(gong)廠里電(dian)(dian)機(ji)類用(yong)(yong)得(de)多，第(di)(di)二種(zhong)用(yong)(yong)得(de)少，只有(you)交(jiao)流電(dian)(dian)焊(han)機(ji)經常用(yong)(yong)到單(dan)相(xiang)380伏(fu)電(dian)(dian)源(yuan)。