| 摘要 |
<p>PROBLEM TO BE SOLVED: To prevent generation of arc between the terminals to be separated when the power supply is cut off at maintenance. SOLUTION: This is a protection device in which a protection plug is fitted detachably to a fixed member and power is supplied to the load side by connecting a movable circuit in the protection plug and a fixed circuit of the fixed member, and generation of arc at the input and the output terminals at the time of power supply cut-off by removing the above protection plug is prevented. An input contact part, a temporary circuit contact part, and an output contact part are provided between the movable circuit of the protection plug and the fixed circuit. In the normal condition wherein the protection plug is inserted in the fixed member, the temporary circuit contact part is opened (non-electric flow state), and at the first stage of removal of the protection plug, while the input contact part and the output contact part are closed, the temporary circuit contact part is closed and connected to the load side, and at the second stage, the output contact part is opened, and at the third stage the temporary contact part is opened, and at the fourth stage the input contact part is opened.</p> |
