静電誘導による電撃評価

摘要

東電設計では，電気保安法人として自家用電気工作物（高rn圧の電気設備）の保安管理業務に参入して3年が経過した。rn点検現場では，高圧ケーブルのシールド（遮蔽層）が除去rnされた箇所（開閉機器などとの接続部近傍）には，十分なrn絶縁が施されているにも拘わらず，感電の恐れがあるのでrn触れないように教えられるが，その根拠は曖昧である。%Threshold level of electric shock perception caused by electrostatic induction generated by 50 Hz alternative current has been studied. The results are summarized below. When the surface of an insulator is wet with hydrophilic condition, the surface acts as a conductor under electrostatic induction, and one may perceive electric shock when he/she touches the surface. In conclusion, the minimum threshold perception voltage is about 1000 V (r.m.s) when one touches the surface, pinching a copper coin in order to lower the resistance. However, the threshold level of perception is not concerned with the voltage or the amount of the electric discharge but a peak value of the current flowing through a subject, furthermore, the length of electric discharge time is also infuluenced. And a peak value of the current is about 1500 mA.