In view of the potential failure at the first end line by using transferring-type arc-suppression device, which cannot accurately select the phase and act reliably, and may further cause the problem of inter-phase short circuit fault in the substation, the first end broken line fault test of the fault grounding transfer device has been carried out in a 10 kV distribution true test field, followed by an analysis of the fault characteristics of the first end of the distribution network. The test results show that the fault of the first end line is similar to the change of the busbar voltage of the single-phase grounding fault. The fault transfer arc suppression device only uses the change of neutral point displacement voltage and the change of phase voltage to judge whether a single-phase grounding fault occurs, which result is not reliable. The phase selection error will occur in this device, therefore, the criterion of the zero sequence current should be increased.