A.TN-S B.TN-C C.IN-C-S D.TT
A.系統(tǒng)電源中性點(diǎn)直接接地B.系統(tǒng)電源中性點(diǎn)不接地C.系統(tǒng)電源中性點(diǎn)經(jīng)阻抗接地D.系統(tǒng)電源中性點(diǎn)經(jīng)滅弧圈接地