PURPOSE: To lighten the burden of an operator during inspection and testing and find out a ground trouble point quickly by outputting operation commands to a scope controlling section and displaying on a display necessary information and the results of alarm signal processing which are preliminarily stored in a scope information storing section.

CONSTITUTION: When a ground occurs in a feeder 32a of a distribution board 31, the name of the ground feeder of the distribution board 31 which is in an alarm state is taken in into a scope controlling section 15 of a display 17 through a data transmitting section 12 of a current leakage alarm 3. In the scope controlling section 15, a distribution one-line diagram including the ground feeder 32a is called from distribution board one-line diagrams of a scope information storing section 13 and a display color of the ground feeder 32a is replaced with that of sound feeders and the recolored feeder is displayed on the display 18. The recolored ground feeder 1a maintains the recolored condition until the ground is released and an reset operation is made from a scope operation inputting section 14. Flicker can be displayed instead of recoloring. By this method, the operator can easily find which feeder has a ground trouble.