Own production medium voltage cells KZO-393


For middle voltage power distribution and control systems , we offer widely used and understandable for the operating staff switchgear  of the KZO type, series 393, 272, and 285 for voltages of 6 (10) kV and a new line of our own design KZO 20 and KZO 35 for voltages of 20 kV and 35 kV respectively.

Switchgear of this type have long proven themselves in small distribution networks of industrial enterprises, civil facilities, infrastructure facilities, and urban distribution networks. This is the type of equipment that is studied first in professional specialized schools. But this doesn’t mean at all that this equipment is very simple and doesn’t have prospects for implementing complex protection and control schemes. The possibility of using medium voltage power contactors makes it possible to implement motor control circuits, and in combination with modern relay protection units, to provide a full range of all necessary types of protection with the possibility of monitoring, remote signaling, and remote control.


The ease of execution of our KZO allows the service personnel to intuitively quickly perform operational switching, and the integration of modern protection systems can block the controls from erroneous actions of the personnel. At the same time, the integrity of the equipment itself is guaranteed, the minimization of erroneous de-energization of energy-consuming objects, and most important thing is the safety of specialists who performs operational switching.

The maximum visualization of the controls of the busbars and linear control devices, in conjunction with the external elements of mechanical and electrical interlocks, even allows you to visually quickly assess the current state of each KZO and the entire switchgear as a whole, and make a technically correct decision on further operational actions.

An important role in the reliability and safety of this product is played by power switching units (switches and contactors) and protection units (Protection and Control Numerical Relays).


The application experience and competence of our company allow us to implement the most diverse combinations of power-switching manufacturers and protection units. We have access and the ability to use our solutions as circuit breakers of the world’s leading manufacturer – Schneider Electric Ind. popular series Evolis, EasyPact EXE, a series of circuit breakers for high-rated currents and short-circuit currents of the LF (6-10kV), SF (20-35kV) brands, a series of specialized VAH generator circuit breakers and Rollarc vacuum contactors, as well as a wide range of different, leading, global manufacturers.


So, for example, it is possible to use the recently widely used switches of the Korean company LS, the Susol VL series. The versatility of our capabilities allows us to optimize the customer’s spare parts inventory range while maintaining the already created “ecosystem” of distribution at the enterprise as a whole, while the final product will certainly be subjected to the entire cycle of acceptance tests

All of the above combinations possibilities of power switching modules can be combined with the preferred types of protection relays. We have competence in the use of relay protection and automation units from Schneider Electriс Ind. (Sepam, MiCOM, Easergy, VAMP), we are aware of and used at different facilities TM ABB and SIEMENS, BMRZ, EKRA, MRZS, and DIAMANT blocks, highly specialized ALTRA modules from IMSKOE.

The modern equipment of our own electrical laboratory allows us to carry out the most complete set of electrical tests, perform relay protection adjustments, and issue test reports.

Our goal is not the production of medium voltage cells in a new and absolutely exclusive design, with individual dimensions without the possibility of being supplemented or supplemented with switchgear already existing at the facility, but the creation of the most adapted to the existing, standard dimensions of the units and the integration of new modern protection, control and safety systems into it.


Particular attention in the development of cells was paid directly to the supporting structure. The increased thickness of the metal, the use of galvanized elements in 97% of the entire cell, without a welded solution with double the thickness of the critical structural elements – this is not only a guarantee of the durability of the structure, but also a margin for safety and dynamic stability in emergencies, and hence an increase in the protection of operating personnel. Therefore, the factors: of durability, quality, resistance to emergencies, ensuring the safety of maintenance personnel, and ease of use are priorities for us.

We especially want to emphasize the advantage of a non-welded solution, although we have all the possibilities for a typical, welded one. The application of our solution requires more time-consuming and technological engineering work on the initial design, a greater number of additional grounding points of the main structure, a more elaborate system of inter-panel connections, and a scheme for selecting special fixing nodes.

 Each pressed-in nut, rivet or “bolt-counter-nut” assembly has a technical justification for the use of this particular element and not another.

In all-welded designs of similar cells, the developers do not think about such things, performing everything in the same way. The seamless solution used by us gives an indisputable advantage – the ability to modernize the cell or replace the internal switching equipment with minimal costs. The structure of the cell being modernized is extracted from the general row of the section, some elements with devices are dismantled and new fasteners and new devices are installed in the existing cell with subsequent installation of the modernized cell in the previously extracted place in the section. After conducting a standard series of laboratory tests, the cell and the RP section are ready for further operation.

All technical solutions and schemes of primary assembly of cells strictly comply with our technical specifications – TU U 27.1-01295813-002:2022. In this document, the maximum possible variants of circuit solutions are selected for the application. 

But it is not always possible to 100% satisfy all requirements for a schematic solution.

Based on the customer’s needs, we are competent to develop any new type of KZO or supplement the existing catalogue of our developments with the necessary schematic solution.

This tabular form summarizes the main technical characteristics of some of the products we manufacture:

Parameter name Parameter value
Rated voltage (linear), kV 6; 10 20 35
Rated current of main circuits, A 630; 1000 630 1250
Rated breaking current of the circuit breaker, kA 20; 25 25 31,5
Rated short-time withstand current, kA 20; 25 25 31,5
Rated voltage of auxiliary circuits, V 220, 100, 36, 12