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

Circuit switcher
Figure 1: Circuit switcher

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 switcher
Figure 2: Circuit switcher for transformer protection, installed on high voltage side
Circuit switcher on high side of transformer
Figure 3: Another instance of a circuit switcher for transformer protection. Image credit: First Energy, Penelec Power.
  • 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.

Learn details of other major equipment
Attempt the quiz
Circuit Switcher: Learn the Purpose, Cost, and Lead Time to Procure 1

Substation Major Equipment

It's only stupid-simple, let's begin.

A transformer develops an internal fault. Which device would you install on the transformer high-side to interrupt fault current?
Question Image
You are building an interconnect station, tying wind farm generation to the power grid. At the substation, the sources are tied through a tie-breaker. Which device would you install to make sure the sources are synchronized?
Question Image
Which combination of devices would you use to implement power line carrier?
Question Image
In a distribution substation, the available ground-fault current on the low side of the step-down transformer is excessive, over-dutying the switching equipment. What is your cost-effective solution to reducing the fault current?
Question Image
What's the purpose of a conventional power transformer?
Question Image
An industrial facility is plagued with voltage flicker (due to harmonics) and poor power factor at the service entrance. Which device would you install to fix both issues?
Question Image
For which event should a surge arrester operate? Check all that apply.
Question Image

Your score is

The average score is 42%


Leave a Comment

Your email address will not be published. Required fields are marked *

Scroll to Top