Purpose of circuit switcher
- A circuit switcher is a switching device like a circuit breaker. It interrupts the power flow.
- It is typically installed on the high voltage side of the transformer.
- Historically the fault interruption capability was lower (~5kA) and therefore was only operated for faults occurring on the load side of the transformer. New-generation switchers can interrupt up to 40kA, making it comparable to a circuit breaker and therefore can be operated for faults occurring on the
sourceand load side.
- Circuit switchers may also be installed at the transmission line terminal. Normally, motor-operated disconnects are installed. However, when opening, the line charging current magnitude can overwhelm the interruption capabilities of the whip of a disconnect. A switcher, when sized correctly, using its SF6 chamber, can safely interrupt the line charging current.
Cost of circuit switcher
- 35kV 600amp 25KAIC capacitor switcher: ~$45,000
- 69kV 600amp 25KAIC capacitor switcher: ~$50,000
- 138kV 600A 25KAIC capacitor switcher: ~$70,000
- 138kV 2000A 40KAIC circuit switcher: ~$40,000
- 230kV 3000A 40KAIC circuit switcher: ~$85,000
- 345kV 1600A 40KAIC circuit switcher: ~$160,000
Note: The cost includes the price of structural steel.
Lead time to procure circuit switcher
- ~18 weeks for a 138kV unit
- ~28 weeks for a 345kV unit
Information on cost and lead time is for your general knowledge only. Contact vendor with your equipment specifications for actual figures.