SF6 Live-Tank Circuit Breakers (72.5–1100kV)

Property Specification

Type: High-Voltage SF6 Live-Tank Circuit Breaker (72.5 kV to 1100 kV)

Features: Engineered with interrupters operating directly at line potential, this breaker utilizes reliable stored-energy spring mechanisms and modular self-compression arc-quenching units (scalable from 1 to 4 interrupters per pole, with optional closing resistors for high-voltage lines). It supports flexible three-pole or single-pole operation on unified or independent base frames, while its structurally reinforced design ensures superior seismic resilience, high mechanical load capacity, and dependable long-term performance.

Applications: Suitable for high-voltage and ultra-high-voltage transmission substations, power grid interconnects, transformer and overhead line switching, generator terminals, and regional power systems requiring high seismic stability and wide voltage coverage (72.5 kV to 1100 kV).

Description

Technical Data & Performance Specifications

Technical Parameter / Specification Single-Break Double-Break Four-Break
Rated Maximum System Voltage 72.5 / 123 / 145 / 170 / 245 / 300 kV 420 / 550 kV 800 kV
Arc-Quenching Units per Pole 1 Chamber 2 Chambers 4 Chambers
Power-Frequency Withstand Voltage (1 min) 140 / 220 / 275 / 325 / 460 / 460 kV 610 / 800 kV 830 kV
Lightning Impulse Withstand Voltage (BIL) 325 / 550 / 650 / 750 / 1050 / 1050 kV 1425 / 1550 kV 2100 kV
Switching Surge Impulse Withstand (SIL) — (850 kV for 300 kV class) 1050 / 1175 kV 1425 kV
Continuous Rated Operating Current 2500 A (for 72.5 kV) / 4000 A / up to 5000 A Up to 5000 A Up to 5000 A
Short-Time Withstand Current (1–3s) 40 kA / up to 63 kA 80 kA (420 kV) / 63 kA (550 kV) 63 kA
Rated Fault Clearing / Break Duration 3 cycles 2 cycles 2 cycles
Standard Rated Operating Sequence O-0.3s-CO-3min-CO or CO-15s-CO O-0.3s-CO-3min-CO or CO-15s-CO O-0.3s-CO-3min-CO or CO-15s-CO
Rated System Grid Frequency 50 / 60 Hz 50 / 60 Hz 50 / 60 Hz
Operating Ambient Temperature Limits -60°C to +55°C* -60°C to +55°C* -60°C to +55°C*
Major Maintenance & Overhaul Interval 25 years 25 years 25 years