Vacuum Circuit Breakers vs. SF6 Circuit Breakers: Which to Choose for Medium-Voltage Power Distribution? - Blog

The selection of medium-voltage power distribution equipment depends on the voltage level and operating conditions: for standard applications (≤27 kV), vacuum circuit breakers are the preferred choice (due to their eco-friendliness and maintenance-free nature), whereas SF6 circuit breakers are recommended for high-performance requirements or frequent switching operations.

Vacuum Circuit Breakers: The Mainstream Choice for Conventional Power Distribution

Eco-friendly:

They do not use greenhouse gases, thereby avoiding the environmental risks associated with SF6 gas-such as the generation of toxic or corrosive particles caused by the interaction of the gas with arcs and moisture-and aligning with major environmental trends.

Suitable for Conventional Voltages: They perform excellently in medium-voltage conventional distribution (e.g., 27kV and below) and are the preferred choice in markets such as China, Japan, and the United States.

Maintenance-free and Intelligent:

They offer long mechanical and electrical lifespans and integrate easily with sensing elements and control systems to enable intelligent, automated operation.

Limitations:

Under specific operating conditions-such as switching off small motors-there is a risk of arc restrike causing switching overvoltage; additional overvoltage suppression measures may be required when necessary.

SF6 Circuit Breakers: A Powerful Tool for High-Spec and Specialized Applications

Superior Breaking Performance:

They possess strong breaking capabilities, making them suitable for high-capacity and frequent-operation scenarios, with no risk of restrike or reignition after breaking.

Excellent Overvoltage Suppression:

They exhibit very low switching overvoltage levels (overvoltage factor below 2.5 times), requiring no external voltage-limiting devices when switching inductive loads such as no-load transformers.

High Insulation and Sealing:

They offer extremely high insulation levels and excellent structural sealing, feature independent gas compartments, and allow for relatively convenient maintenance.

Limitations:

Under the combined influence of electric arcs and moisture, the gas may generate toxic or corrosive decomposition products; furthermore, in some regions, its environmental performance is inferior to that of vacuum technology.

Final Selection Recommendation

If your system voltage is 27 kV or lower and does not require extremely frequent switching, vacuum circuit breakers are the preferred choice; their environmental friendliness and maintenance-free nature align better with modern power distribution trends.

If the system voltage exceeds 27 kV, or if the application involves high-capacity breaking, requires exceptional safety, or demands extremely frequent operation, SF6 circuit breakers are recommended.

When you need LTZ-40.5 Indoor High Voltage SF6 Circuit Breaker, please contact us at any time.