Product Overview

The integrated primary and secondary pole-mounted circuit breakers (box-type, hood-type) are a complete product that combines the pole-mounted circuit breaker with the intelligent boundary switch controller (feeder terminal FTU).

This device is installed at the responsibility boundary point of the 12KV distribution line user incoming line, and can also be installed on branch lines or terminal user lines that meet requirements. It enables current detection for ground fault current, overcurrent fault detection, comprehensive protection control functions, and three-remote communication functions. It can automatically eliminate single-phase ground faults on controlled branches and the same short-circuit faults on controlled branch lines, improving power supply reliability and automation levels.

The integrated primary and secondary integrated circuit breaker equipment is based on the requirements of our company's State Grid standard "Typical Design of Primary and Secondary Complete Distribution Equipment." It integrates electronic voltage sensors, electronic current sensors, energy metering modules, high-speed fault transient recording, and other technologies, including pole-mounted complete circuit breaker equipment.

Overall requirements

The primary and secondary integrated sets of pole-mounted circuit breakers can be divided into four complete sets: segmented load switch sets, segmented circuit breaker sets, boundary point load switch sets, and boundary point circuit breaker sets.

The segmented load switch set is mainly used for trunk line segmental/connection positions: to achieve local automatic isolation during trunk line faults, supporting voltage-time homogeneous logic

◇ The segmented circuit breaker set is mainly used to meet grade difference requirements, can directly cut off major branch links of faulty trunk lines, and features a closing function.

 ◇ Boundary load switches and boundary circuit breakers mainly achieve local isolation or removal of terminal faults for users.

 ◇ The pole-mounted switch complete set equipment features comprehensive local feeder automation functions. This complete set does not rely on the distribution automation master station or communications, achieving adaptive comprehensive local automation functions. Through short-circuit/grounding fault detection technology, voltage-free switching, and fault path adaptive delayed power oncoming and closing, it adopts an adaptive multi-branch, multi-link distribution network structure to achieve local line selection, regional positioning and isolation for single-phase ground faults, and achieves fault area isolation and power supply restoration in non-fault areas through two recloggings. Suitable for installation on overhead lines in urban (rural) networks with medium-voltage distribution networks, this complete distribution circuit breaker enables intelligent monitoring of 1-2 loop overhead line operations, remote control, line protection, and high-voltage line loss metering. Mainly used for segmenting and interconnection functions of 12kV distribution network backbone lines.

 ◇ The switch body, control unit, and voltage transformer are connected using military-grade aerospace plugs via outdoor fully insulated cables.

 ◇ The switch body and control unit meet State Grid's requirements for Q/DW514 distribution automation terminal/substation function and technical requirements for distribution automation terminals.

 ◇ LW3-12/T630-20SF6 pole-mounted circuit breakers, ZW20-12 series SF6 pole-mounted vacuum circuit breakers, ZW32-12 pole-mounted vacuum circuit breakers. Their complete sets are widely used in 12KV substations, industrial and mining enterprises, protection and control of urban and rural grids, automated distribution networks of urban and rural grids, and various frequently operated distribution sites.

Functional requirements

● The integrated primary and secondary pole-mounted circuit breakers (box-type, hood-type) are products that combine the pole-mounted circuit breaker with the intelligent boundary switch controller (feeder terminal FTU);

● The primary and secondary column circuit breakers consist of the switch body, control unit, power voltage transformer, connecting cables, etc.;

● The switch circuit breaker is equipped with a built-in high-precision, wide-range voltage/current sensor to meet fault detection, measurement, metering, and line loss calculation requirements;

● The switch circuit breaker uses a built-in set of voltage transformers providing Ua, Ub, Uc (measurement, metering) voltage signals; a built-in set of current transformers providing la, Ib, lc (protection, measurement, metering) current signals; two external power voltage transformers are installed on both sides of the switch and circuit breaker, with line voltage signals taken from the power voltage transformers;

● Capable of collecting three-phase current, three-phase voltage, zero-sequence current, and zero-sequence voltage, meeting the needs for calculating active power, reactive power, power factor, frequency, and calculating electrical quantities;

● Equipped with interphase fault handling and small-current single-phase ground fault handling functions, capable of directly tripping to eliminate faults, with automatic reclosing function adjustable number and duration of reclosing.

Technical specifications

Main electrical technical parameters

Main mechanical characteristic parameters

Technical parameters of the spring operating mechanism

Coil technical specifications

Technical parameters of the permanent magnet operating mechanism

Dimensions diagram