SF₆ Gas-Free 123kV Eco-Tank Type Vacuum Circuit Breaker Developed and Launched
Meiden Co., Ltd. (hereinafter Meiden) has developed a 123kV Eco-Tank Type Vacuum Circuit Breaker. Sales of this product for the North American market commenced in October 2025 through Meiden America Switchgear, Inc. (hereinafter Meiden America Switchgear), an overseas subsidiary of the Meiden Group.
BACKGROUND:
In the North American market, regulations on SF₆ gas—which has a greenhouse effect 23,500 times greater than CO₂—are being strengthened, particularly in California. Consequently, circuit breakers using SF₆ gas are being phased out in conjunction with new substation installations and the replacement of aging equipment.
In 2020, Meidensha America Switchgear was established, launching sales of 145kV Eco-Tank vacuum circuit breakers. By fiscal year 2024, the company had shipped approximately 1,300 vacuum circuit breakers.
Anticipating continued growth in demand for vacuum circuit breakers, we have now developed a 123kV Eco-Tank vacuum circuit breaker with a single-pole switching mechanism to further enhance product competitiveness.
123kV Eco-Tank Vacuum Circuit Breaker
FEATURES:
Vacuum circuit breakers face significant challenges in achieving higher voltages compared to gas circuit breakers. We have successfully achieved a high voltage rating of up to 123kV using a single-pole switching system. The 145kV Eco-Tank vacuum circuit breaker employed a two-point breaking system, featuring two vacuum interrupters per phase arranged in series, to meet breaking performance requirements. The single-point breaking system achieved in this product offers a simpler structure compared to the two-point system, leading to enhanced product competitiveness through reduced manufacturing costs.
Internal Structure of Vacuum Circuit Breaker
OTHER FEATURES:
SF₆ gas is not used, eliminating the need for gas recovery during equipment disposal. This contributes to reduced lifecycle costs.
The dry air used as the insulating medium does not liquefy even at ambient temperatures as low as -50°C, eliminating the need for anti-liquefaction heaters even in cold regions.
Electrically long-lasting (10,000 load current operations). No internal inspection required, significantly reducing maintenance costs.
The use of aluminum for the outer sheath material results in extremely low conduction losses. Additionally, no touch-up painting is required during maintenance.
FUTURE OUTLOOK:
In recent years, not only in the North American market but worldwide, demand for new and upgraded substation equipment accompanying power grid development is increasing, while stricter SF₆ gas regulations are anticipated. Meidensha has captured the need for higher-voltage vacuum circuit breakers and will use the development of this high-voltage model up to 123kV as an opportunity to work on developing a 245kV product with two-point switching.
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