ASL-410 series digital line protection and monitoring device including ASL-411 (two component) and ASL-412 (three-element) model, a small current grounding system applicable to the voltage levels of 66kV and below, with current and voltage protection 110kV lines, the equipment of the line unit, the spacer layer. Main functions: a) three sections of the direction of low-voltage lockout overcurrent protection: each piece of low voltage lockout lockout or direction can be individually cast back; b) three-phase auto-reclose function; c) low-frequency load shedding features: Low-voltage lockout and current atresia may cast retire, selectable the UFLS exports trip or alarm; d) small current grounding line selection function; e) zero-sequence current protection function: export tripping or alarm selectable; f) event recording, fault recording. Note: In addition to these basic functions, ASL-412 increased than ASL-411 reclosing seized the same period / seized without pressure.