Disconnecting circuit breakers (DCB)
Siemens has developed a device in which the isolating distance has been integrated in the SF6 gas compartment in order to reduce external environmental influences. The DCB (disconnecting circuit breaker) is used as a circuit breaker and also as a disconnector – two functions combined in one device. An additional air-insulated earthing switch can be mounted onto the supporting structure for voltages up to 145 kV.
Overview of our disconnecting circuit breakers (DCB)
Our DCB combines the strengths of our proven product portfolio. This innovative device saves space and cuts costs while offering the highest reliability and safety.
- Combination of circuit breaker and disconnector in one device
- No visible opening distance due to the SF6-insulated disconnector function
- Compact mechanical interlock which guarantees that the circuit breaker stays in the open position when used as a disconnector
- Position indicators for monitoring
- Optional air-insulated earthing switch (up to 145 kV)
- Highest reliability by applying well-proven and established components from Siemens circuit breakers and earthing switches
- Highest availability due to reduced maintenance interruptions
- Cost- and space-saving solution by combining two devices into one
- Minimized costs for transportation, maintenance, installation and commissioning, as well as civil engineering work
- Compact and intelligent interlocking and position indicating device for greater safety
- From a single source: documentation and technical support, assembly and installation, customer training, 24-hour service
Our DCB family
Like all of our circuit breakers, the core components were taken from our other circuit breakers, disconnectors and GIS product family in line with our proven modular design. The disconnecting circuit breakers are type-tested according to class M2 and C2 of IEC 62271-108, a specific standard for combined switching devices.
The disconnecting circuit breaker for 145 kV has a three-pole operating mechanism with a common base (FG), and a single-pole operating mechanism on separate bases (FI) for 420 kV.
|Number of interrupter units per pole
|Rated power-frequency withstand voltage
||275 or 315
||520 or 610
|Rated lightning impulse withstand voltage / min
||650 or 750
||1425 or 1665
|Rated switching impulse withstand voltage
||kV||1050 or 1245
|Rated normal current, up to
|Rated short-time withstand current (1s - 3s), up to
||-40 up to +40
|Rated operating sequence
||0-0,3 s-CO-3 min-CO or CO-15 s-CO
|Rated break time
||Hz||50 or 60
All values in accordance with IEC; other values on request
Downloads, support and services
Our services for you
You can find details on our portfolio of disconnecting circuit breakers and information about our services here.
One device – two functions
Our DCB for 145 kV and 420 kV applications is used as both a circuit breaker as well as a disconnector. We can gladly help you find the ideal solution for your requirements.