SF6 Circuit Breaker Manufacturer — Gas Circuit Breakers 11kV to 500kV

An SF6 circuit breaker is a gas circuit breaker that uses sulphur hexafluoride (SF6) as both the arc-quenching medium and the insulating medium. SF6 circuit breaker working principle: when the contacts separate under fault current, the SF6 gas — either in a puffer type or self-blast design — is directed across the arc. SF6’s superior dielectric strength rapidly absorbs free electrons, extinguishing the arc and restoring insulation. This makes the SF6 gas circuit breaker ideal for medium-, high- and extra-high-voltage switching from 11kV to 500kV.

We manufacture the full SF6 circuit breaker voltage range from 11kV MV SF6 breakers up to 500kV EHV SF6 gas circuit breakers. Specific ratings include 11kV, 33kV, 36kV, 66kV, 110kV, 132kV, 145kV, 220kV, 245kV, 400kV and 500kV SF6 circuit breakers — in indoor, outdoor and gas-insulated (GIS) configurations, including SF6 ring main units.

SF6 circuit breaker gas pressure varies by voltage class. Typical SF6 circuit breaker gas pressure in bar: MV breakers (11–36kV) operate at 0.4–0.5 MPa (4–5 bar) filled pressure; HV and EHV breakers (66–500kV) use 0.5–0.7 MPa. Each SF6 gas circuit breaker is supplied with a gas pressure monitoring system that triggers low-pressure alarms before reaching the SF6 circuit breaker pressure level minimum. Full SF6 circuit breaker specifications are provided in our technical datasheets.

The main SF6 circuit breaker types are: (1) Puffer type SF6 circuit breaker — gas is mechanically compressed by a piston on opening; (2) Self-blast (non-puffer) SF6 circuit breaker — arc energy itself heats and pressurises the SF6 gas for quenching; (3) Live tank SF6 circuit breaker — interrupters mounted on top of the bushing in an earthed tank arrangement; (4) Dead tank SF6 circuit breaker — interrupters housed inside a grounded metal tank; (5) SF6 ring main unit (RMU) — compact, gas-insulated switchgear for distribution networks. We supply all types.

All our SF6 gas circuit breakers are type-tested to IEC 62271-100 and, where required, IEEE C37 (ANSI). SF6 circuit breaker testing procedure is independently witnessed by labs such as KEMA. We provide complete type-test reports (SF6 circuit breaker testing procedure PDFs), Factory Acceptance Test (FAT) documentation, SF6 circuit breaker specifications sheets and SF6 circuit breaker construction and working principle drawings with every order.

SF6 circuit breaker price depends on voltage class, rating and quantity. MV SF6 breakers (11–36kV) typically ship in 4–6 weeks; EHV SF6 circuit breakers (220–500kV) may require 10–16 weeks. Submit an inquiry below for a tailored SF6 circuit breaker price quotation and full technical specification within 24 hours.