A.過載小于5% B.過載小于15% C.過載小于20% D.過載小于10%
A.過載10%~20% B.過載10%~50% C.過載20%~50% D.過載30%~50%
A.過電流大于50% B.過電流大于60% C.過電流大于70% D.過電流大于80%