Description: A short-circuit detection principle shown in Figure when the line short-circuit fault, the fault indicator sensitive to fault current, the indicator will turn red white display window (or by not emit light into light). According to two-phase indicator line B # 3 # 2,5,8 and 3,6,9-line C-phase indicator flop (or light) and 11, 12 indicator does not flop (or no light), you can quickly determine the fault for the D point. Second, the ground fault detection principle sampling ground instantaneous capacitor current first half-wave and ground instantaneous voltage first half-wave, comparing the phase, when the sampling ground instantaneous capacitor current mutation and is greater than a certain value, and with the ground instantaneous voltage of the first half-wave of the same phase while the wire-to-ground voltage is reduced, it is determined a ground line, otherwise the circuit grounding occurred. As shown by the two-phase line C # 3,6,9 indicator display and 12 indicator flop action yet, you can determine the D point of a ground fault occurs. Third, the action criterion (1) It≥160A It mutant amount current starting value (2) △ ??I≥0.5I0 △ I I0 is the current rate of change for the front line short-circuit current (3) I = 0 I was after a line fault current (4) 0.06S≤ △ T≤3S △ T mutation in time for the current four, the technical parameters apply voltage 6 ~ 35kV, different voltage levels may be different load currents 0-1200A parameters applicable outside diameter wire fault 25mm2-400mm2 factory default reset time value 12h, 24h Ambient temperature -35 ℃ ~ 75 ℃ to action times ≥5000 times the weight ≤500g battery life> 3-5 year plant life> 3-5 years of wind capacity wind 150km / h for non-releasable determine the short-circuit fault indication diagram: the two-phase 2,5,8 line B # 2 # line indicator and the indicator turned red C with 3,6,9 and 11 show still white indicator and 12 indicators, namely to determine the point of a short circuit fault D