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SDTKKBS-12 Series
Ring Main Unit

SDTKKBS-12 Series Ring Main Unit Cover


SDTKKBS-12 Series Ring Main Unit is a complete set of electrical equipment that integrates advanced technologies such as electromagnetic voltage/current transformer, electric energy metering module, high-speed fault transient filtering and so on. The SDTKKBS-12 series is composed of load switch unit, circuit breaker unit, bus equipment unit (PT) , centralized DTU, loop-in loop-out unit and etc., and those units are connected by military-grade circular connector. The SDTKKBS-12 series can collect active power, reactive power, power factor, frequency, zero sequence current and zero sequence voltage. The SDTKKBS-12 series also has the functions of line loss measurement, electric energy measurement, circuit voltage identification, voltage/load over limit alarm, short-circuit fault detection and processing, and single-phase grounding fault detection and processing. In addition, the SDTKKBS-12 series ring main unit unit also supports uploading of short circuit/ground fault events to meet the automation needs of the distribution network. The SDTKKBS-12 series can be customized according to your needs.


On the basis of the traditional DTU function, we have added a distribution line loss collection function, optimized the judgment and location function of small current ground faults, and increased the sampling frequency so that the waveform of the fault recording is closer to the real waveform.

● Line loss collection function

The distribution line loss collection module is used to realize the interval electric energy collection function, and the electric energy data on the line is measured in real time, including: forward and reverse active power and four quadrant limited reactive power, so as to realize the two-way metering function and support the positioning function;

● Small current ground fault judgment and location function

Through the data analysis and collection of phase current transformer and zero sequence current transformer, the control unit judges these characteristic quantities through a variety of algorithms, so as to accurately locate the area where the fault occurs;

● Disturbance recorder function

Through 128-point sampling per cycle and complete recording of the remote signal information such as the channel waveforms and open positions of the 4 cycles before the failure and 8 cycles after the failure. The remote signal information will be sent to the help station for analysis of the cause of the failure, and 64 fault oscilloscope information is supported cyclic storage.


● Using voltage-time type electromagnetic mechanism or normal spring operating mechanism;

● With normal protection, voltage-current, and distributed intelligent FA function;

● Using centralized and decentralized network control terminal and clear distribution network automation system, which is intuitive and easy to use;

● Using CVT electronic voltage sensing technology;

● Using vacuum arc extinguishing, and built-in isolation fracture and vacuum arc extinguishing chamber series asynchronous linkage, which has strong switching ability, and high safety;

● Using super capacitor backup power supply to avoid system instability caused by maintenance devices such as batteries;

● The circuit breaker/load switch can be assembled in any cabinet, which is flexible and convenient.

● The controller takes the line voltage as the criterion, and handles local fault handling through delayed closing and substation protection to realize the complete function of feeder circuit automation, without the need of batteries and relying on the communication and the master station;

● Using frequently-operated load switches/circuit breakers to meet the economic operation requirements of distribution network automation;

● Using three-phase common cabinet layout, porcelain sheathed cable and cast wire, fully sealed mechanism, military-grade circular connector, and overall fully sealed technology to ensure strong weather resistance, good anti-condensation performance, and maintenance-free for 15 years;

● The shell is processed by mold drawing and one-time molding process, with IP67 protection level, easy to seal the box, high air tightness, and high mechanical strength;

● The main circuit of the load switch/circuit breaker, the secondary components and the operating mechanism are all sealed in SF6 gas (zero gauge pressure), which is not affected by the external environment, and has stable, reliable, and maintenance-free performance.

Technical data-sheet

SDTKKBS-12 Series Ring Main Unit How to order

Technical scheme example

SDTKKBS-12 Series Ring Main Unit Technical scheme example