三相電加熱管

        380伏三(san)相四線(xian)電(dian)(dian)(dian)(dian)路中，任意(yi)兩根(gen)火線(xian)之間的電(dian)(dian)(dian)(dian)壓(ya)都是380伏，任意(yi)一根(gen)火線(xian)與零線(xian)之間都可以組(zu)成220伏。這個系統(tong)可以形成三(san)種(zhong)電(dian)(dian)(dian)(dian)源：即單(dan)相220伏電(dian)(dian)(dian)(dian)源，單(dan)相380伏電(dian)(dian)(dian)(dian)源，三(san)相380伏電(dian)(dian)(dian)(dian)源，第(di) I 種(zhong)家用(yong)比較(jiao)多，第(di)三(san)種(zhong)工廠里電(dian)(dian)(dian)(dian)機類用(yong)得(de)多，第(di)二種(zhong)用(yong)得(de)少，只有(you)交流電(dian)(dian)(dian)(dian)焊機經常(chang)用(yong)到單(dan)相380伏電(dian)(dian)(dian)(dian)源。