A completely dry 126 kV outdoor termination is a unique development of the Izolyator-AKS plant

On 6 December 2021, the Izolyator-AKS plant began mass production of a new product — a 126 kV dry self-supporting outdoor termination.

Изолятор-АКС

Izolyator-AKS plant is a developer and manufacturer of high-voltage cable accessories of all types for voltages from 126 to 252 kV for cable cross-sections up to 2500 mm² (cable joints, outdoor terminations and cable connectors). The enterprise was founded in April 2019 as a result of the diversification of production by Izolyator, which has a century of experience in the creation and production of high-voltage insulation equipment. The first products were manufactured in the second quarter 2020. Since September 2021, Izolyator-AKS has been a plenipotentiary member of the International Association ‘Electrocable’. Cable accessories are manufactured on the most modern and unparalleled injection molding machines. All manufactured products undergo tests in own testing laboratory equipped with unique test equipment. The Izolyator-AKS enterprise includes a multifunctional service center.

This is a domestic development with unique design solutions and great potential for use at the power facilities of the Rosseti Group, capable of replacing oil or gas-filled terminations in the next few years, which are currently operated in electrical networks of voltags of 126 kV and higher.

Сухая концевая муфта
Dry outdoor termination with composite insulator ISKM-126, developed by Izolyator-AKS

The fundamental difference lies in the shape of the stress cone, which is designed to work in the absence of a liquid or gaseous dielectric. This design, from the point of view of economy, not only does not lose to oil- and gas-filled counterparts, but in the long term even surpasses them in terms of efficiency of use in the electric power complex.

стресс-конус сухой концевой муфты 110 кВ
Employees of the Izolyator-AKS enterprise demonstrate the stress cone of a 126 kV dry termination to the representative of the RusCable.Ru portal Alexandra Lukina

Viktor Pshennov, Technical Director of Izolyator-AKS, named eight advantages of the ISKM type dry termination:

  • the reliability of the termination is significantly increased due to the absence of a liquid or gaseous phase in the design and, accordingly, the elimination of the possibility of its leakage;
  • simplifies the supporting structures and the installation process due to the lower mass of the coupling compared to existing analogues;
  • the coupling can be installed at any angle, since there is no liquid in the design;
  • simplifies and accelerates the installation of the coupling by eliminating the operation of filling with a liquid or gaseous dielectric;
  • no additional supporting structures are required — the coupling design is self-supporting;
  • the field compensation element (stress cone) does not require additional assembly, since it is completely manufactured at the Izolyator-AKS enterprise;
  • the coupling does not require filling with SF6 gas and can be operated at low temperatures without the need for additional heating and gas pressure control;
  • the termination is a one-piece construction that does not include the cable gland’s parts.


The RusCable.Ru portal is visiting Izolyator-AKS. On photo, L-R: Technical Director of Izolyator-AKS Viktor Pshennov, Director of Marketing and Special Projects of RusKabel Media Holding Sergey Kuzminov, Production Process Engineer of Izolyator-AKS Alexander Filippov and Deputy Technical Director of Izolyator-AKS Alexander Danilov

The creation of a domestic high-voltage and ultra-high-voltage cable system is a strategically important task that must be solved within the import substitution initiative.

The implementation of this large-scale project is an absolute priority for Izolyator-AKS, which is a unique engineering and production center for the development and production of high-voltage cable accessories.

The new development of Izolyator-AKS — the dry termination ISKM-126 — is the result of an evolutionary approach to the development of power transmission and distribution technologies, which allows to consistently improve the safety and efficiency of the power grid of the Russian Federation.

Based on materials of the RusCable.Ru portal.