总功率8KW、每相电热管额定电压380V时,电热管每相电阻:R=U*U/(P/3)=380*380/(8000/3)=54欧,角接电流:I=P/1.732/U=8/1.732/0.38=12A,星接电流:I==380/1.732/54=4A