| 摘要 |
PURPOSE:To contrive safety by a method wherein a grounding truck can never be inserted by mistake under a condition that a main circuit is being charged. CONSTITUTION:A guide rail 11 for a grounding truck is provided on a floor surface 4b. An electromagnet 14, having a plunger 13 released from excitation under a charging condition but excited under the condition of service intrruption and returned to a non-exciting condition by a spring 12 under the condition of service interruption, is laid in the guide rail 11. A pair of lock rods 15, going in-and-out orthogonally to the guide rail 11, is attached to the plunger 13. A retaining body 17, retained under a condition that the lock rod 15 is led out and released from the retaining under a condition that the rod is led in, is projected to the lower surface of the earth truck. Under charging condition, the electromagnet 14 is moved by the spring 12 and the lock rod 15 is projected out of the guide rail 11 whereby the retaining body 17 is retained and the earth truck can not be inserted. |
