??? PIR-DY shift change with low voltage protection box Intelligent integrated protection devices for mine mobile substation low voltage protection box covers 380V, 660V, 1140V, 3.3kV voltage, 50 ~ 1000A rated current, all-digital tuning and calibration . With undervoltage | overvoltage | overload | short circuit | equilibrium | leakage lockout | leakage protection | protection insulation monitoring, etc.; with four RS485 remote communication functions; with calendar clock; with fault memory and search functions; experiment with menu function. Functional, targeted, long-term stable and reliable. Certified by EMC testing and proof testing center. Measurement parameters 1 ,? Rated current: 50 ~ 1000A 2 ,? Rated voltage: 10VAC 3 ,? Rated frequency: 50Hz 4 ,? measurement content: U, I, R 5 ,? Accuracy: ± 5% 6 ,? switch Input mode: (at + 25 ℃) 1 optically isolated environment, altitude does not exceed 2000m, pressure is 80kPa ~ 110kPa 2, ambient temperature of -5 ℃ ~ + 55 ℃ 3, ambient air relative humidity less than 95% 4 In no significant damage to the insulation of gas environment 5, local standards to prevent dripping configure host a current transformer 6 Power 1