ASB-411 digital transformer backup protection device is suitable for 35kV and below voltage substation transformer backup protection, differential protection device with AST-411 with the completion of the main transformer secondary function of the spacer layer. Main function of a) three-step (or two sections of two time limits, optional) composite voltage startup overcurrent protection; b) two-stage zero sequence voltage lockout zero sequence overcurrent; c) zero-sequence current lockout zero sequence overvoltage protection ; d) The overload protection function; e) low-voltage protection function; f) low-frequency protection function; g) of current unbalance protection function; h) PT disconnection and insulation monitoring function. i) event logging, the fault recorder ASB-4101 digital factory transformer protection and monitoring devices applicable to auxiliary transformer protection, complete protection, monitoring and control, and other functions. Main functions: a) three-stage complex voltage startup overcurrent protection; b) zero-sequence voltage latch the high-pressure side of the zero-sequence two-stage over-current and high-voltage side of the zero-sequence current lockout zero sequence overvoltage protection; c) low-voltage side of the zero-sequence segment overcurrent protection; d) The overload protection function; e) low-voltage protection function; f) body protection function: the heavy gas action, over-temperature trip, light gas alarms and over-temperature alarm; g) of the PT disconnection and insulation monitor function ; h) event logging, fault recording current position: Products --- ASD-411 digital motor protection and monitoring of integrated substation automation system device ASD-411 digital motor protection and monitoring device suitable for high voltage motor 3kV to 10kV small current grounding system for spacer layer device complete protection, monitoring and control, communications, and other functions. Main functions: a) definite time overcurrent protection and negative-sequence current protection; b) stall protection; c) start-up time is too long protection; d) inverse-time overcurrent protection and inverse time negative sequence current protection; e) overheating protection; f) protection of low-voltage and voltage phase sequence protection; g) the overload alarm; h) PT disconnection and CT of small current grounding line selection function; i) zero-sequence current protection function; j) break monitoring function. k) event logging, fault recorder ASR-411 digital the main transformer integrated monitoring and control device as a complement of the transformer primary protection and backup protection functions, the main achievement of telemetry, remote, remote control and remote adjustment feature. The main functions: a) device with a measuring current