K-123 for Automation of Electrical Circuits with Digital Relay Protection and Emergency Controls

Complete device (CD) K-123 (hereinafter referred to as “K-123”) is an upgraded version of K-112 CD.

K-123 is intended to enhance the reliability of 6-10 kV overhead power transmission lines due to automatic segmentation of overhead lines with double- and single-way feed, automatic load transfer, network backup and separation of overhead power transmission lines into sections to ensure the failure-free operation of the substations outside the area with a damaged substation.

It is used for connections in specific electric motors, packaged transformer substations, shopping malls, garage and horticultural cooperatives, power supply specific settlements, industrial and agricultural consumers, as well as for black ice melting.

K-123 is equipped with a microprocessor unit of relay protection and emergency controls, allowing automation of the process of the overhead power transmission lines monitoring.


Description of Parameters

Parameter Value

Rated voltage (linear), kV

6; 10

Maximum working voltage (linear), kV

7.2; 12

Rated main circuit current, A

400; 630; 800

Rated breaking current, kA


Conventional thermal current (3 c), kA


Short time electrodynamic current, kA


Type of embedded circuit-breaker

VBP **

Working temperature range, °C

Varying from –60 to +40

Level/type of insulation


Service conditions


Rated voltage of auxiliary circuits AC, V


Dimension sizes, mm:

990 x 810 x 3925

Weight, kg:


* the time of flow of conventional thermal current via grounding switches – 1 c.
** upon the preliminary approval by the manufacturing plant, one may prepare a device with BB/TEL circuit-breakers