Please tell me about vacuum circuit breakers?

Question

I need to do a seminar on Vacuum Circuit Breakers.
But, from searching net, i couldn't find muchinfo.
Please provide some info on it... even links about it will be great help.
Thanks in advance...

Answer 1

Vacuum technology for circuit breakers was "perfected" in the early 80's and beat out SF6 in medium voltage switchgear and motor starters in the US in general applications, although SF6 is still available it is not the preferred type. The electrical contacts are housed in a porcelain "bottle" and are approximately 0.500" apart. There is a stationary contact and a movable contact that is attached to the breaker mech. They are available in voltages from 600V to 38KV. I am not sure if vacuum breakers exist above 38KV, probably do but I have never seen one. There are some 600V bottles available but they aren't used very much. The greatest advantage of vacuum was the ability to shrink the size of the breakers and allow for 2 high breaker construction of switchgear, ie breaker in bottom cell and breaker in top cell. As an example a 3000A 15KV GE Magnablast air circuit breaker weighs in at about 4000lbs, a comparable vacuum breaker weighs about 400lbs. Westinghouse had a vacuum bottle plant in Horseheads, NY, I am pretty sure it's still there but is now part of Eaton Electrical (Cutler Hammer) All US manuf have vacuum breakers, CH, GE, Siemens, Square D, Etc. You can go to these manufactures web sites and search for switchgear or electrical distribution, they all have breaker manuals available for download. Here is the site for Eaton's "Dog and Pony" about vacuum bottles, which are the heart and soul of vacuum circuit breakers. At one time they controlled the majority of the market for bottles.

http://www.eatonelectrical.com/NASApp/cs/ContentServer?pagename=C-H/Common/AssetTemplateLink&c=Apubarticles&cid=1077779854531&Sec=products

Answer 2

The important question is why are you doing a seminar on a subject you know nothing about?

Answer 3

http://www.osha.gov/SLTC/etools/electric_power/illustrated_glossary/substation_equipment/vacuum_circuit_breakers.html

You may also wish to contact makers and sellers, who will be happy to provide sales literature.