As the CTO of Medium Voltage at Schneider Electric, I see it as a responsibility to pause and challenge how we think. And that starts with a simple question:

“If we were to design medium‑voltage switchgear today—starting from a blank sheet, fully informed by today’s sustainability, regulatory, and operational expectations—how would we define it?”

This question matters as the electrical industry undergoes a major transformation: the shift away from SF₆ gas. This invites us to revisit some long‑standing language we use to describe medium‑voltage systems, and to educate engineers. How about we educate those who will design, deploy, and maintain the power systems of the future.

Does our language still reflect reality?

For decades, medium‑voltage switchgear has effectively been described through two familiar categories, Gas‑Insulated Switchgear (GIS) and Air‑Insulated Switchgear (AIS). At the same time, technical standards such as IEC 62271‑200 applied a more engineering‑driven definition, based on whether equipment is metal‑enclosed with insulation provided by a gas at other than atmospheric pressure in a sealed tank, or metal‑enclosed with insulation relying on ambient air in a non sealed enclosure. These two definitions have been used for many years. That was largely because SF₆ dominated medium‑voltage technology, making gas a natural reference point.

That context has now evolved. 

In recent years, SF₆‑free technologies have made considerable progress. In Schneider, Pure Air insulation and Shunt Vacuum Interruption Technology enable this. No F‑gases or proprietary gas are used. Just pure air—abundant, simple, and universally understood.

As a result, when gas is no longer central to system performance, it is reasonable to question whether “gas” should continue to define the name.

A future‑ready approach

Looking at today’s technologies, a new direction can emerge—one that feels closely aligned to IEC definition and terminology and is based on the key structure of the switchgear with sealed tank. Based on this perspective, I would propose thinking in terms of Pressurized Air and Ambient Air switchgear.

Pressurized Air would describe fully enclosed systems, sealed for their entire operational lifetime with purified air at pressure above atmosphere. This architecture offers well‑established benefits: compact footprint, controlled internal conditions, reduced exposure to environmental factors such as dust, humidity, or pollution, and stable, predictable performance over time. These attributes remain highly relevant, particularly when paired with SF₆‑free insulation technologies.

Ambient Air, by contrast, would describe systems designed with accessible compartments or component architectures that support maintenance flexibility, repairability, and adaptation across the equipment lifecycle, and that suit applications where accessibility and operational evolution are priorities.

By shifting the focus away from what is inside the enclosure and toward factors such as enclosure philosophy, environmental exposure, footprint constraints, maintainability, and long‑term operability, Pressurized Air Switchgear and Ambient Air Switchgear may offer a more intuitive way to describe how medium‑voltage systems are designed and used today.

A framework for the next generation

Clear and consistent terminology plays a significant role in how energy systems are understood and passed on. For future electrical engineers, language that is technically meaningful, aligned with sustainability, and free from SF₆‑era assumptions can provide a clearer foundation.

This is one possible way to build a shared language, a proposal intended as a starting point for discussion, for all SF6-free alternatives in the market. If you have a view, a question, or a different take, I’d be glad to continue the conversation—feel free to share your thoughts in the comments. Any shift toward a common language will require time, alignment, and continued dialogue across industry, academia, and certification bodies. This is simply an invitation to keep that discussion moving.

As your advancing energy technology partner, this represents an opportunity to evolve the language of power systems, so it keeps pace with the technology itself—for this generation, and for those to come.

About the author

Christophe Preve, CTO of Medium Voltage

He graduated from the Ecole Supérieure d’Electricité (SUPELEC) in 1988. He started working in a Grenoble, France utility as an Electrical Network Operator and then as an Electrical Studies Manager. He joined Schneider Electric in 1994 in the Protection Relay Department as an Electrical Network Expert. He had the opportunity to write a book on “Protection of Electrical Networks” in Edition Hermès. In 1998, he moved to MV Switchgear Activity where he took different responsibilities in R&D. He is now responsible for new product development and new technology integration. He is also a lecturer at the ENSE3 Engineering School in Grenoble.