移動式起重機誤觸架空高壓電線感電事故之防止對策研究

A Study on Methods for Preventing Electric Shock Accidents about Mobile Cranes Touching High Voltage Power Lines

本文檢討移動式起重機誤觸架空高壓電線的感電事故發生原因，並提出感電發生時的處理方法，以及根本防止感電事故發生的對策。文中首先討論起重機誤觸高壓電線時，勞工所站立的地點與感電事故的關係，並由此說明安全的操作方式。文內藉試驗被覆電線的性能，以評估被覆電線是否可以減少起重機誤觸高壓電線的感電發生。當起重機誤觸架空線時，現今配電系統的保護方式在偵測故障電流的困難，以致未能使變電所自動切離電力。對於預防起重機誤觸架空高壓線的感電事故上，短期措施要求操作員應取得操作資格並加強電氣安全訓練及工作時能使用絕緣防護套管。中期措施建議架空配電裸線改為被覆電線。長期措施係研究偵測高阻抗接地故障的電驛。

This paper examines the causes of electric shock events when mobile cranes accidentally touch high-voltage power lines, the methods for handling the accidents, and the strategies for avoiding those shocks. During the accident, it is ensured that the people in the cranes could not be electricly shocked, and this is proved by the Faraday Cage experiment. By test results of the coated wires, it is concluded that these wires can reduce electric shock events. When cranes touch power lines, it is hard to detect the fault current by the protection system in the substation. So the substation could not switch off power lines automatically. In order to prevent the electric shock events about mobile cranes touching highvoltage power lines, in the short term, operators should have operation qualification and emphasized electric safety training, and insulation tubes should be used. In the intermediate term, coated wires are suggested to replace naked wires. In the long term, the relays that can detect high impedance line-ground faults are required.