A.20μL/L B.15μL/L C.10μL/L D.8μL/L
A.40kV/2.5mm B.50kV/2.5mm C.60kV/2.5mm D.70kV/2.5mm
(A)工頻電壓升高 (B)電弧接地過電壓 (C)變電所侵入波過電壓 (D)鐵磁諧振過電壓