Ask Experts Questions for FREE Help !
Ask

Theory of vacuum Circuit Breaker & sf6 circuit breaker

Asked Jun 28, 2007, 07:30 AM — 15 Answers
I want to know about the basic Theory of vacuum Circuit Breaker & sf6 circuit breaker

15 Answers
alectrician's Avatar
alectrician Posts: 7, Reputation: -1
New Member
 
#2

Apr 22, 2008, 06:55 PM
First off, sf6 stands for sodium hexafloride gas which is inert, Siemens did some stuff in a 500kv switchyard I worked in and with a SF6 breaker the air gap is about 6 inches and the switch size is measured in inches, compared to the "old" air breakers that are huge (larger than your garage) and sounded like a cannon going off when they opened. With SF6 your switchyards and main disconnects can be very unobtrusive at a time when substations are NIMBY. My experience with them was fine although much closer tolerances are required(mm not inches)
rudrainternatio (May 27, 2008 06:15 PM): It is partial answer   Source:
Helpful
schaefer101's Avatar
schaefer101 Posts: 1, Reputation: 1
New Member
 
#3

Mar 24, 2009, 12:12 PM
Sulphur hexafluoride (SF6) is an inert, heavy gas having good dielectric and arc extinguishing properties. The dielectric strength of the gas increases with pressure and is more than of dielectric strength of oil at 3 kg/cm2. SF6 is now being widely used in electrical equipment like high voltage metal enclosed cables; high voltage metal clad switchgear, capacitors, circuit breakers, current transformers, bushings, etc. The gas is liquefied at certain low temperature, liquefaction temperature increases with pressure.
Sulphur hexafluoride gas is prepared by burning coarsely crushed roll sulphur in the fluorine gas, in a steel box, provided with staggered horizontal shelves, each bearing about 4 kg of sulphur. The steel box is made gas tight. The gas thus obtained contains other fluorides such as S2F10, SF4 and must be purified further SF6 gas generally supplier by chemical firms. The cost of gas is low if manufactured in large scale.

The previous answer was inept.

Medium-voltage circuit breakers rated between 1 and 72 kV may be assembled into metal-enclosed switchgear line ups for indoor use, or may be individual components installed outdoors in a substation. Air-break circuit breakers replaced oil-filled units for indoor applications, but are now themselves being replaced by vacuum circuit breakers (up to about 35 kV). Like the high voltage circuit breakers described below, these are also operated by current sensing protective relays operated through current transformers. The characteristics of MV breakers are given by international standards such as IEC 62271. Medium-voltage circuit breakers nearly always use separate current sensors and protection relays, instead of relying on built-in thermal or magnetic overcurrent sensors.

Medium-voltage circuit breakers can be classified by the medium used to extinguish the arc:

Vacuum circuit breaker
Helpful
Michael Garces's Avatar
Michael Garces Posts: 1, Reputation: 1
New Member
 
#4

Jul 8, 2009, 01:48 PM
Quote:
Originally Posted by alectrician View Post
first off, sf6 stands for sodium hexafloride gas which is inert, Siemens did some stuff in a 500kv switchyard I worked in and with a SF6 breaker the air gap is about 6 inches and the switch size is measured in inches, compared to the "old" air breakers that are huge (larger than your garage) and sounded like a cannon going off when they opened. With SF6 your switchyards and main disconnects can be very unobtrusive at a time when substations are NIMBY. My experience with them was fine although much closer tolerances are required(mm not inches)
What is really SF6 stands for?it is sodium hexaflouride or sulfur hexaflouride?
Helpful
reignoffire's Avatar
reignoffire Posts: 1, Reputation: 10
Junior Member
 
#5

Aug 6, 2009, 06:09 PM
SF6 stands for sulphur hexafluoride...
Helpful
sivani's Avatar
sivani Posts: 2, Reputation: 1
New Member
 
#6

Aug 29, 2009, 01:44 PM
Quote:
Originally Posted by prashantkolhe View Post
I want to know about the basic Theory of vacuum Circuit Breaker & sf6 circuit breaker
& construction &display the each and every parts with photograph
Helpful
sivani's Avatar
sivani Posts: 2, Reputation: 1
New Member
 
#7

Aug 29, 2009, 01:47 PM
Quote:
Originally Posted by prashantkolhe View Post
I want to know about the basic Theory of vacuum Circuit Breaker & sf6 circuit breaker
display the each and every parts with photograph
Helpful
nivaldosilveira's Avatar
nivaldosilveira Posts: 1, Reputation: 1
New Member
 
#8

Oct 8, 2009, 05:51 AM
Hy srs,

I would like to know if you know some suppliers os Eletric Panels in SF6 for 36kV.

I want to buy a lot of and I need to quote urgently.

Thanks

Nivaldo

nivaldojs@weg.net
Helpful
surag1982's Avatar
surag1982 Posts: 1, Reputation: 10
Junior Member
 
#9

Oct 21, 2009, 11:40 PM
Nivaldosilveira, please. Send your contact details to email: surag1982@gmail.com
Helpful
rumon's Avatar
rumon Posts: 1, Reputation: 10
Junior Member
 
#10

Feb 1, 2011, 03:19 AM
What sf6 switchgear
Helpful

Not your question? Ask your question View similar questions

 
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Add your answer here.

Remove Text Formatting

Undo
Redo
 
Decrease Size
Increase Size
Bold
Italic
Underline
Align Left
Align Center
Align Right
Ordered List
Unordered List
Decrease Indent
Increase Indent
Insert Email Link
Wrap [QUOTE] tags around selected text
Wrap [CODE] tags around selected text
Wrap [HTML] tags around selected text
Wrap [PHP] tags around selected text
Wrap [YOUTUBE] tags around selected text
Notification Type:



Check out some similar questions!

Maximum load on 20 amp circuit breaker [ 14 Answers ]

I am aware of certain normal maximums. I guess I'm looking for somebody to tell me that I'm pushing things too far, or not. I want to hook up a portable air conditioner (Sunpentown WA-1220E) which is rated at 950 watts (and, mysteriously, at 9.0 amps) along with an HP 4Si printer, which is rated...

20amp circuit breaker, 15 amp receptacles [ 2 Answers ]

I have a 20amp circuit breaker with 15 amp receptacles and light switches on #12 wire with a load of 1700, is this allowable? If not, and I change to a 15 amp circuit breaker, is the 1440 watt safety load in the code or is it a non-code safety suggestion?

Circuit breaker [ 3 Answers ]

A circuit breaker connected to the kitchen tripped twice. I had an electrician in but the problem persists - in fact, the very day the electrician came. It does not seem to be caused by any one particular appliance. The first time I was using the waste disposal and the next two times nothing was...

Replacing a circuit breaker with a GFI breaker- q on neutrals [ 1 Answers ]

In process on installing withquestion on neutral wires. Do you take the neutrals out of the in the main panel neutral and put them in into the breaker where its labelled "load neutral terminal" and only have the neutral "pig tail" to the panel neutral bar? Thanks!

Kenmore Stove Trips 50 AMP Circuit Breaker [ 3 Answers ]

1 Year old Kenmore Stove, Flat Top keeps tripping my 50 AMP circuit breaker. This stove has worked without problem for 1 year without any problems. What confuses me is that the circuit breaker is tripped whether I use the range, the oven, or both at the same time. Could the breaker be bad? To...


View more Engineering questions Search