Intelligent (Self-Powered) Passive Protection Device
Intelligent (self -powered) protection device of ST260E is new developed equipment. This device adopted multiple patents, and its technology index improved greatly. It is suitable to operate in unattended power substation with bad ambient outside door.
• Device ST260E adopts high-integrated, internal bus wire of chip processor which deals with signal coming from CT and PT, and control relay-output via digital logic calculation. It adopts sealed case, maintenance–free design and anti-interference performance, which are suitable for ring-grid net cubicle with bad running ambient and compact mounting position.
• Device adopts extremely low-consumption technology to ensure reliable function rapidly starting up at any conditions 
• Device ST266F with design features as simple and small structure and flexible and convenient installation approach is suit for ring-grid net cubicle with compact installation conditions.
• Self-powered function (power-supply by CT) eliminate external burden brought by installing DC panel or USP. 
• Protective functions of ST260E provides three-stage phase to phase overcurrent protection, two stage earth grounding protection, multiple IEC standard inverse curves to be selected, and voltage protection.
• Inrush current blocking function is offered to avoid tripping for error caused by putting on operation transformer with no load.
• Instantaneous protection adopts short-data-window fast algorithm to real rapid tripping short-circuit fault and to avoid override tripping.
• Adopting Chinese word LCD interface, multiple-layer menus display, Chinese and English language exchanging selection, and window design with event-pop up, as well as extremely friendly HMI. 
• Flexible and completed protecting functions which could be switched freely via control words are added in device.
• 1A or 5A rated current CT could be sampled for design of measurement circuits with automatically dynamic increasing-revenue and extremely width measurement scope.
• Users could either select 50Hz or 60Hz system frequency or choose zero-sequence current obtaining mode as external sampling mode of internal calculation mode.
• Strength acquiring-energy circuit design, extremely absorbing peak voltage circuits ensure security and reliability of power supplying loop.
• Inputting Hybrid voltage to power circuit is allowed, either accessing power-windings of CT, or inputting DC48V or DC24V voltage. 
• Extremely width temperature range of running, waterproof design sure that it is possible to run in extremely ambient conditions. 
• Maximum number of History record stored is 255 . Record will not be lost for power off. It is convenient for fault trading. 
• Device provides RS-485 communication port and open communication protocol to realize SADAD function.