# Circuit Switcher: Learn the Purpose, Cost, and Lead Time to Procure

#### 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 source and 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.

##### Attempt the quiz
/7

Substation Major Equipment

It’s only stupid-simple, let’s begin.