Explain the working principle of Vacuum circuit breaker and
Air circuit breaker

Answer Posted / sk.raffique

When two current carrying contacts are separated in a
vacuum module, an arc is drawn between them. An intensely
hot spot or sparks are created at the instant of contact
separation from which metal vapor shoot off, constituting
plasma. The amount of vapour in the plasma is proportional
to the rate of vapour emission from the electrodes, hence
to the arc current. With alternating current arc, the
current decreases during a portion of wave and tends to
zero. Thereby the rate of vapour emission tends to zero and
the amount of plasma tends to zero. Soon after natural
current zero, the remaining metal vapour condenses and the
dielectric strength builds up rapidly, and restriking of
arc is prevented.

This principle is used in vacuum circuit breakers

Is This Answer Correct ?    45 Yes 9 No



Post New Answer       View All Answers


Please Help Members By Posting Answers For Below Questions

Why computer humming sound occurred in ht transmission line?

663


Application Comparison between 22KV (UE)and 33KV (E) system. Are we allowed to use 33KV (E) cable in lieu of 22KV (UE) cable. What are the technical disadvantages.

2307


Define active and passive network?

679


Define corner frequency?

772


Difference between shunt, PMG and AREP excitation. Which is the most reliable between PMG and AREP.

9026






We are designer please help me calculate the size of 11kv cables from step up transformer to M.V panel, total load is 5 mega watt distance 900 feet (used aluminum type cables) please provided formula for calculate the cable with example.

1221


I am getting above 60 V as open delta voltage against single phase unit ICT at tertiary delta formed and ICT getting trippped on NDR. ICT tested and found in order. PTs provided on tertiary are tested and in order. what may be the reason?

1319


If I want to replace a 26KW Slip ring Motor with a Squirrel Cage motor & Drive (for a Hoist Application). How can I approximate the Motor & Drive HP required in new Setup.

1830


If we have to feed a housing complex having load 8MVA, than what would be the better option, either we first step down 33kv supply into 11kv & than 430v or we proposed no of 33/.44 kv transformer, also which option is economical?

1696


what will be d.g. capacity to cater together for 14hp A.C. load & 3kw lighting load

1561


volts=230 c=10mf a=??

1587


how tto ingress mw in turbine explain.procedure ?

1755


FEINGING DECREASES THE FLUX DENSITY IN THE AIR GAP. HOW?

1686


if i am in front of transmission line how to know that current direction without any equipment

1269


what will be project cost for 100 kv transformer connection under oyt scheme.

2421