| 摘要 |
PURPOSE:To cut off the insulating current transformer to be excluded from pilot wire, by switching pilot wire with a switch through the insulating current transformer without danger of high voltage invasion. CONSTITUTION:A switching device which is composed of contact points 53,54 for switcing to switch on and off pilot wire 20, relay 5 for switching to operate contact points for switching, and an insulating transformers 6, 7 for giving switching instruction to switching relay is provided, and selecting terminal to be stopped and terminal to be used, stopped condition or used condition is switched. Pilot wire with danger of high voltage invasion can be switched by pilot wire switching device through an insulating transformer without danger of high voltage invasion, and also, the insulating current transformer T to be excluded can be cut off from pilot wire. Still, switching condition can be maintained even at stoppage of electric source for switching. |
