Once a switchgear is installed, it is expected to operate safely and reliably for decades. That is why development is not only about meeting today’s requirements, but also about creating solutions that are prepared for tomorrow’s power grids, changing environmental conditions and increasing demands on operational and personnel safety.
At KL Industri, the development of our SF6-free switchgear, unerRING, has been a long-term commitment spanning more than a decade.
“Our ambition has always been the same. We want to offer switchgear that is safe, reliable, flexible and virtually maintenance-free throughout its entire service life,” says Niklas Adolfsson, Electrical Design Engineer at KL Industri.
Early to embrace SF6-free technology
More than ten years ago, the market began sending clear signals. Grid operators were looking for alternatives to SF6 gas, while sustainability became an increasingly important consideration. Since then, the transition has accelerated, and under the EU F-Gas Regulation, it has been prohibited since 1 January 2026 to commission new medium-voltage switchgear and circuit breakers up to and including 24 kV containing SF6 or other fluorinated gases.
When the development of unerRING began, the selection of SF6-free medium-voltage switchgear on the market was still very limited.
“We recognised where the market was heading and decided to invest early. We began developing a solution specifically designed for Nordic conditions, focusing on high operational reliability in demanding environments with humidity, temperature variations and long service life requirements.”
The result was unerRING. Its second generation, which remains the version we deliver in the highest volumes today, was launched as early as 2015. In 2021, the next generation, unerRING+, was introduced, and the product family continues to evolve to meet the demands of tomorrow’s energy infrastructure.
Safety built into the design
One of unerRING’s greatest strengths lies in its design.
Unlike many conventional solutions, unerRING features a single-phase encapsulated design. Each phase is separated by epoxy insulation, while the switching device uses vacuum interruption technology instead of gas insulation. In addition, all current-carrying components and operating mechanisms are fully enclosed within an IP67-rated enclosure.
This design eliminates the risk of internal phase-to-phase faults and prevents an internal arc from occurring between the phases. The result is a high level of personnel safety while reducing the demands placed on the outer enclosure, making the switchgear particularly well suited for compact secondary substations and indoor applications.
Built for flexibility
Power grids continue to evolve. New connections are added, capacity expands and substations often need to be adapted over time.
That is why unerRING has been developed as a modular system.
Each switchgear is assembled bay by bay and can easily be expanded long after installation. The busbar arrangement allows additional modules to be connected with minimal effort, providing excellent flexibility for both new installations and future upgrades.
“We always think long-term. A switchgear should not only meet today’s requirements but also be able to grow alongside our customers’ networks for many years to come,” says Niklas.
KL Industri offers several bay configurations, including load break switches, fused load break switches, circuit breakers, as well as solutions for network automation and intelligent protection relays. This allows every switchgear configuration to be tailored to the customer’s specific application.
unerRING or unerRING+ – what's the difference?
Both unerRING and unerRING+ are based on the same core platform and offer the same high level of operational reliability. The primary difference lies in the cable earthing arrangement.
In unerRING, earthing is performed using a combination of a switch and a selector disconnector. The operation is completed in two steps, where the disconnector provides the visible isolation point and the switch performs the earthing making capacity.
In the enhanced unerRING+, a dedicated earthing switch is positioned closest to the cable connection, followed by the disconnector and finally the switching device. This creates a three-step operation and provides a clearer earthing method for customers requiring that configuration.
Every switchgear is tested before delivery
Every switchgear undergoes comprehensive electrical testing before leaving the factory.
After assembly, dielectric testing is carried out to verify insulation performance and overall functionality before delivery or installation in one of KL Industri’s prefabricated substations.
“We want our customers to feel the same confidence when commissioning a switchgear as we do when it leaves our production facility. That’s why testing is an essential part of our quality assurance process.”
Proven technology with market-leading delivery times
Since unerRING was introduced, KL Industri has grown to deliver approximately 5,000 unerRING bays every year, corresponding to around 1,300 complete switchgear units annually. Both production volumes and the customer base continue to grow, with unerRING now serving an increasing number of network operators across the Nordic region.
For Niklas, the product’s long track record remains one of its strongest competitive advantages.
“SF6-free switchgear has gained significant attention in recent years due to new legislation, but we’ve been working with this technology for much longer than that. Our customers benefit from a solution that has been thoroughly proven — both through extensive testing and many years of successful operation in real-world installations.”
Another important advantage is delivery performance. Through long-term supplier partnerships, careful production planning and advanced material forecasting, KL Industri can offer what is likely to be some of the shortest delivery times on the market.
“For our customers, choosing the right switchgear is only part of the equation. Receiving it when they need it is equally important. That’s where our planning, supply chain and production processes give us a clear competitive advantage,” concludes Niklas.