- 著者
-
池田 武弘
- 出版者
- 一般社団法人 資源・素材学会
- 雑誌
- 日本鉱業会誌 (ISSN:03694194)
- 巻号頁・発行日
- vol.98, no.1138, pp.1225-1229, 1982-12-25 (Released:2011-07-13)
- 参考文献数
- 7
It has been already proved that intrinsically safe circuit voltages can be used from 2 V to 800 V for explosive gas atmosphere, but these values have no relation to electric shock accidents.On account of the reason intrinsically safe circuit voltages in coal mines have been controlled less than about 25 V to prevent electric shock accidents customarily.In case of a fault voltage occured at a part of circuit, however, if the product of the touch voltage and its touch time exists within a certain range, the incidence of electric shock accident will be very low.In this paper the author describes an experimental study of the allowable voltage in intrinsically safe circuit which is based on a small touch time which don't lead to the impediment in a human body under usual circumstances.Synthesizing the experimental results of each paragraph of this paper, the conclusion is as follows;(1) In case of a circuit containing the bare electrode is stalled at a soaked point, usable voltage is under AC 25 V or DC 60 V.(2) In case of a circuit containing the bare electrode is stalled at a point usual dried or a circuit not containing the bare electrode, usable voltage is under AC 100 V or DC 200 V.As for over voltages above mentioned, if the intrinsically safe construction is kept in drip-proof increased safety construction, it will be usable to AC and DC 800 V.