Switcher/Breaker
Switcher/Breaker
(OP)
1. What is the difference between a dead tank circuit breaker and a live tank circuit breaker? What does 'dead' and 'live' stand for?
2. What are the main differences between circuit switchers and circuit breakers? Why would you choose one over the other?
(Feel free to answer one or both, thanks)
2. What are the main differences between circuit switchers and circuit breakers? Why would you choose one over the other?
(Feel free to answer one or both, thanks)






RE: Switcher/Breaker
RE: Switcher/Breaker
RE: Switcher/Breaker
There are construction differences between live and dead tank technology. Dead tank breakers is build with two bushing per phase capable to hold 3 BCTs. The entire assembly can be mounted in a single foundation pad. Live tank breaker chamber is build in a hallow insulator (porcelain or polymer) without BCT. The three poles units typically are vertically mounted in a steel structure that required at least two foundations piers.
Circuit switchers may not have reclosing capability and typically rated for 20 or 31 kA up to 230 kV. Circuit breakers are typically designed for 40kA or 63 kA with reclosing and or single pole capability rated to clear fault in 2 to 3 cycles and capable to operate in HV or UHV
Circ. Switcher could be used to protect transformers while circuit breaker could be used for applications up to 765 kV or higher
RE: Switcher/Breaker
Thread248-37438
Thread238-25889
Thread238-40469
RE: Switcher/Breaker
1. IEEE Std 100-2000 "Dictionary"
a) Circuit Switcher is a circuit interrupting device with a limited interrupting rating as compared with a circuit breaker. It is often integrated with a disconnecting switch. Its design precludes the integration of current transformers with all associated ramification of it.
b) Circuit Switcher is a mechanical device with an integral interrupter, suitable for making, carrying, and interrupting currents under normal circuit conditions. It is also suitable for interrupting specified short-circuit current that may be less than its close and latch, momentary, and short-time current ratings. This device may be suitable for transformer protection where the majority of faults are limited by transformer and system impedance.
RE: Switcher/Breaker
Dead tank CB's enable you to consider the CB as a complete subsystem from the supplier, ready to connect, with BCT's already mounted and marshalled in the control cubicle.
If your protection scheme has diff prot with cross over of CT zones, then the DT CB will accept more easily CT's on both sides of the CB.
From a user perspective, modern 38kV gas-insulated DT CB's bring the benefit of virtually no maintenance and excellent protection from environment(pollution, ice,...).
Also, I found that DT CB's offer better performance and type testing than standard live tank, such as internal arc fault withstand, seismic withstand, and the gas-insulated environment preserves the BIL level over time.