Talk:Circuit breaker

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I modified the description of "common trip" breakers and took out the description of "low voltage". --Wtshymanski 19:21, 17 Dec 2004 (UTC)

I tweaked the description a little more with what I hope is better language explaining where two-pole, common trip breakers are used. By the way, does it conform to the code to tie two single-pole breaker handles together to try to form a common-trip breaker? Given "Free trip" mechanisms, I don't think you can assure that the handle tie will actually trip the "other" pole. I know I wouldn't want anything other than a true two-pole, common-trip breaker.

Atlant 19:38, 17 Dec 2004 (UTC)

Yes, I like that much better. Of course you can have two-pole breakers on a 120/208V panelboard, or I suppose on a 240/415V board, or on a DC board. --Wtshymanski 19:40, 17 Dec 2004 (UTC)

Contents 1 Categories 2 High-voltage Circuit breakers 3 ELCBs and the USA 4 Switchgear? 5 high voltage 6 Switching speed 7 Type Of MCBs

[edit] Categories

Tiny circuit breakers, that you can put in a pocket, might be electronic components. Small breakers, that you can lift, maybe with the help of a friend, might be found in electrical distribution. Big breakers, that show up in SCADA screens at system control centers, are pretty plainly electric power transmission devices. And the 30,000 amp breakers attached to generators are power components. Am I the only one finding the categorization of the article to be unclear? That's why I like the category electrical engineering- it fits anything with wires on it. Do the extra categories actually help Wikipedia users? --Wtshymanski 22:44, 8 May 2005 (UTC)

I agree. But you also need to look at how the categories are arranged. It appears, for example, that Category:Electrical engineering includes as subcategories things like Category:Electric power and Category:Electrical components. So maybe it shouldn't be in the supercategory on electrical engineering, but rather in several different subcategories under that. I think that someone has been carried away with removing categories from several articles similar to this, but if there is problem itmay lie in a poorly thought out category structure. (Or the structure may be brilliantly arranged, I don't think I'm going to try to sort it all out, I'll let others put in their two cents' worth on that.) Gene Nygaard 23:16, 8 May 2005 (UTC)

[edit] High-voltage Circuit breakers

I have completed the text with a description of interrupting principles used for HV circuit breakers (SF6 breakers as it is the technology now used for breakers 72,5 kV and above) Dingy 23 July 2005

Thanks for this addition!

Atlant 11:35, 25 July 2005 (UTC)

The images that illustrate the interrupting principles have been published in many publications or conference papers in India, France, China, Algeria.... there is no copyright, I am in fact close to the source.

Concerning the title "Internal details of a European breaker" , now that the part on high-voltage circuit breakers is more developed I think that it is necessary to change the title to "Low voltage European Circuit breaker" or something like that..; dingy 26 July

Even if these images are not copyrighted, might it be a good idea to include a reference? I mention this especially because five of the six images used in the section "High-voltage circuit breakers" appear in one publication. The publication is: "Technical Trends in Circuit Breaker Switching Technologies", published in the CIGRE SC A3 Colloquium in Sarajevo, 2003. The authors are all listed as being from Alstom T&D (transmission and distribution). Although I have an electronic copy of the publication, online I have found referneces to it but no copy. Michapma, August 21

Good idea, you should do it Dingy 00:59, 22 August 2006 (UTC)

[edit] ELCBs and the USA

A comment in the article asked:

Were ELCBS that detect earth fault current directly ever used in the USA and if so what were they reffered to as?

If by ELCBs the questioner was referring to devices that measured, for example, the isolation between the power leads and ground/earth, then no, they have never been used in ordinary installations in the US. Because our power distribution systems almost always use a grounded neutral, there isn't any isolation to speak of.

Note that this is not true in specialized installations. For example, a large delta-connected motor, generator, or distribution circuit can certainly be isolated from ground and could be protected by an ELCB. Diesel-electric railroad locomotives frequently used just such an ELCB, energizing the traction motor circuits a small DC voltage away from ground and then measuring the current required to maintain that voltage (which ought to approach zero if the traction motor circuit was correctly isolated from the frame of the locomotive, but certainly became non-zero if, say, the traction motors became saturated with water).

But in ordinary practice, especially residential practice, it's all balance-fault interrupters.

Atlant 19:31, 17 July 2005 (UTC)

afaict what was reffered to as an ELCB in the uk had two seperate earth terminals and detected current flow between them. E.G. one terminal would be attached to the earthing system and one to the earth rod. I think they were only generally used on TT systems though.

[edit] Switchgear?

I do not agree with this analysis. CIrcuit breakers in combination are called switchgears, which should be stated.

220.227.235.82

Well, this is Wikipedia so you know what to do: be bold!

Atlant 21:07, 14 August 2005 (UTC)

A circuit breaker is a type of Switchgear that is designed to break load current and extinguish an arc. Generally switchgear is the description given to any high voltage electrical switching equipment and covers a variety of equipment such as circuit breaker, air break switch disconnectors (ABSD's), earthing switches etc..

[edit] high voltage

This page gives the impression that in high voltage engnineering cuircuit breaker means something somewhat different from what it means in low voltage wiring. in low voltage wiring a cuircuit breaker is something that detects a fault and automatically disconnects the supply. it seems in high voltage it means a device that breaks the cuircuit (which may be triggered by hardware sensing overcurrent that doesn't seem to be part of the breaker). Is this impression correct and if so should it be worked into the article somehow.

also the high voltage cuircuit breakers section is getting HUGE we should probablly break it out into a seperate article. Plugwash 16:43, 22 January 2006 (UTC)

That is correct. Any breaker rated in multiple KV will generally have a trip coil operated by external protective relays, which might be anything from electromechanical plunger-type relays up to digital (numeric) multi-function systems capable of significant programmability and complexity. The "detection" and "interruption" are done in separate places, and if this is new to some then it's good that Wikipedia includes this data. Unluckily we've got a lot of electrical articles written at the home handyman level and as important as that level is in its own sphere, encyclopedia articles need to be more inclusive.

There's quit a lot on arc interruption but it is important and presents the fundamental issue in circuit breaker design. It's important to show the contrast between small breakers and large breakers...the illustration of the small Euro breaker is great. Bitty breakers are kind of dull..HV is cool. --Wtshymanski 23:32, 22 January 2006 (UTC)

I'm not saying we shouldn't keep some information on high voltage breakers here and it *IS* interesting but right now that section is bigger (in terms of rendered screenfulls) than the rest of the article combined. definately a case for sumarising and moving to a more specialist article. Plugwash 01:09, 23 January 2006 (UTC)

Hi, in the French version done later ("Disjoncteur à haute tension"), I made a separate article, a little more complete. The same could be done here, while keeping some text in this one. Dingy 04:02, 23 January 2006 (UTC)

[edit] Switching speed

"The double motion technique halves the tripping speed of the moving part" - I take this to mean that the total execution time has doubled? Perhaps the author meant tripping time instead?--Hooperbloob 08:05, 27 November 2006 (UTC)

sorry for my bad english, the meaning is as flows : if one contact (of a 245 kV breaker) moves you ned a speed of 8 m/s, if both contacts move in opposite direction, each needs a speed of 4 m/s (halved) in order to have the same relative speed of 8 m/s. Is it clear now ? Dingy 13:42, 27 November 2006 (UTC)

[edit] Type Of MCBs

Could anyone tell me where are we suppose to use Type B MCB, Type C MCB and so on...?

Let's say a 20A Type-B MCB is connected to a current carrying conductor. At what current will the MCB trip? Is it slightly above 20A or 3-5 times the rated current as stated in the article? —The preceding unsigned comment was added by LHW (talk • contribs) 10:30, 15 December 2006 (UTC).

MCBs are thermal magnetic hybrids, the thermal part follows a smooth curve of faster tripping as current increases and deals with overloading but even in the best cases its pretty slow to trip. The magnetic part trips at the points given in the article and when it trips it trips as fast as the mechanism can physically move (iirc the standard says less than 100ms). Plugwash 01:11, 16 December 2006 (UTC)