Manufacturer: Hitachi Energy
Original publication date: 5 May 2026
Topic: Ultra-high-voltage SF₆-free circuit breakers
Hitachi Energy has presented new EconiQ dead-tank circuit-breaker technologies for 800 kV and 420 kV systems at the 2026 IEEE PES T&D Conference in Chicago.
Declared ratings
The manufacturer identifies an 800 kV, 63 kA dead-tank circuit breaker and a 420 kV, 80 kA dead-tank circuit breaker. Hitachi Energy says the designs avoid SF₆ while targeting the reliability and dielectric performance required by ultra-high-voltage transmission systems.
The company also published additions to its wider SF₆-free high-voltage roadmap, including 170 kV, 40 kA and 800 kV, 50 kA live-tank circuit-breaker solutions planned for 2026.
Technical significance
- 800 kV equipment serves long-distance bulk transmission applications.
- High short-circuit ratings increase the electrical and mechanical demands on the interrupter and enclosure.
- Removing SF₆ at these voltage levels addresses assets that may remain in service for several decades.
Why it matters
Moving SF₆-free technology into the highest voltage classes broadens the choices available to transmission operators. However, a product announcement is only one step in project qualification. Utilities will still evaluate type-test evidence, switching duties, seismic and environmental requirements, interface dimensions, monitoring, service strategy and operational references.
The ratings also should not be read as a single universal configuration. Final capability depends on the exact breaker design and project application.
Source note: This is an independent editorial summary prepared by Learn Switchgear. Product ratings and roadmap statements are attributed to Hitachi Energy. Read the original Hitachi Energy press release.