A 220kV substation in Ningxia: the vibration of the outer shell of the I isolated switch of the substation is obvious. After several measurements of the detection system developed by the project group, the vibration signal is determined to contain high component, the internal contact fault features are obvious, and then the X ray detection is carried out specially for this place, and it is found that the A phase and the B apart from the close contact contact are not complete. In the contact of the plum blossom, the movable contact is inserted only to the lower edge of the first clasping spring on the static contact side, and the dynamic contact of the isolating switch is not fully contacted. Therefore, the mechanical fault is caused by the abnormal vibration signal of the shell.
