New Compact Secondary Substations Launched to Meet SF₆-Free Market Requirements
In 2025, we successfully completed the development and type testing of several new compact secondary substation (CSS) solutions designed to meet evolving market requirements, particularly following the ban on SF₆ in medium-voltage equipment. These developments were driven by the needs of major European utilities, including E.ON, Caruna, and Elenia.
The transition to SF₆-free medium-voltage solutions has resulted in larger equipment dimensions, requiring adjustments to compact substation designs. In response, our engineering team developed a new generation of substations that combine compliance with updated regulations, compact design, and high operational reliability.
New Compact Secondary Substation Models
As part of this development program, the following new models were introduced:
HEKA2VM1600-1 – metal substation with two transformers
HEKA1SB1250-1 – concrete substation with one transformer
HEKA1VM315-8 and HEKA1VM315-9 – metal substations with one transformer
HEKA2VB1250-1 – concrete substation with two transformers
In addition, two further solutions were launched for specific applications:
HEKA1SM6300-1, designed for large-scale solar parks
HEKA1VM1600-3, primarily used in Sweden as an IBH24 station for medium-voltage connections of end users
Designed for Utility and Renewable Energy Applications
Several of the new substations are part of ongoing E.ON tenders and are also suitable for other markets, including Estonia and Finland. The solutions support a wide range of configurations, with transformer ratings up to 6,300 kVA, flexible medium-voltage RMU layouts, and low-voltage panels up to 2 × 2,500 A.
All completed designs have successfully passed the required type tests, including internal arc classification, temperature rise, earthing short-circuit, and enclosure protection tests. Type testing for the HEKA2VB1250-1 solution is currently underway.
Supporting the Energy Transition
These new compact secondary substations demonstrate our ability to respond quickly to changing regulatory and market demands while maintaining high standards of safety, quality, and reliability. The portfolio supports utilities and energy developers in their transition toward more environmentally friendly and future-proof power distribution solutions.
We would like to thank our engineering and project teams for their dedication and expertise. Their strong collaboration and commitment were key to delivering these new solutions successfully.
For more information about the new compact secondary substation models, please contact us or explore the detailed product descriptions available on our website.
