Talk:Circuit breaker

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

message: 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)
replies: text: 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)
thread_title: Categories

message: 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)
replies: text: 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.
There is one more use in the US. Installations over 250V to ground and 1200A require a variant of the ELCB.  Normally, these use electronics and CT's to measure the current and react accordingly.  — Preceding unsigned comment added by LightRobb (talk • contribs) 02:12, 21 January 2015 (UTC)
thread_title: ELCBs and the USA

message: 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)
thread_title:  Switchgear? 

message: "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)
replies: text: 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)
thread_title: Switching speed

message: It should be noted that the listed standard low voltage molded case braker values are British or European sizes based on European standards and 240v system.  The US sstandard values are different.  —Preceding unsigned comment added by Mattmia2 (talk • contribs) 13:12, 20 September 2007 (UTC)
thread_title:  Standars Values 

message: There are various types of high current, high voltage circuit breakers used by Power Industries,  such as Air Blast, Minimum Oil, Vacuum, SF6 gas filled, Magnetic arc-quenched varieties etc. Apart from making or breaking the current flows in Power Lines, their main functions are to extinguish electric arcs that follow a circuit-current break.  In an arc channel between two parting contacts one may delineate three distinct regions, viz, two thin regions attached to the parting electrodes and a central column. The thin regions act as interfaces conjoining the high density and low velocity e-flow within the electrodes and the low density and high velocity e-flow in the usually long central column. Such interfaces at anode are rather diffused and current densities are relatively low whereas at cathode end they are focused and current densities are high. The Electrical parameters on either side of this interface are widely separated and the mechanisms operative here are very complex.  Only at low pressures, the interfaces at cathode end are spread out and some theoretical analyses as well as diagnostics of the arc parameters have been attempted.
All circuit breakers in general, are designed to extinguish the arcs by drawing out their central columns using an air blast, a gushing oil stream or a pinching magnetic field etc guided more by mechanical constructional conveniences. But, in general, an arc is relatively ‘strong’ and ‘stable’ at the mid-column regions and rather weak at the electrode interfaces, particularly at Cathode surface. Attempts to extinguish arcs at such weakest points should be beneficial as regards total energy dissipation and delay to extinction and hardly any report on such efforts is available. Initial experiments to verify the concepts may be pursued with only simple, plane parallel, stationary electrodes.  Would any users be interested to participate in developing the theories / devising the experiments in this direction? We shall develop a model of the processes active in the cathode interface of the arcs shortly.  —Preceding unsigned comment added by 210.211.202.164 (talk) 08:23, 25 October 2007 (UTC)
thread_title:  Speed up Arc Extinction 

message: In the headlines "Rated current" and "Short circuit current".  —Preceding unsigned comment added by Yossso (talk • contribs) 23:10, 20 August 2008 (UTC)
thread_title:  duplication of text 

message: The amount of content in the high voltage section suggests that stopping the current from flowing is not trivial. Perhaps this should be stated explicitly. Reading the article I infer that arcing is a normal occurence when trying to stop the current flow, and requires special measures to stop it (stop it safely?). I am no expert on the subject so I'm hesitant to edit.
Walworth (talk) 11:40, 21 January 2009 (UTC)
thread_title: reasons for complexity of high voltage circuit breakers

message: The reason most prospective users are interested in looking up circuit breakers, is for help in choosing an appropriate type. 
Of paramount importance is how the breaker attaches to the buss bar. The amount of space allotted to extraneous technical details crowds pertinent information off the page. As a user who has experienced breaker failure due to poor engineering I am in interested in basic construction.
How about someone who has the needed information creating a simple page which contains information that is needed by the prospective customer. Pictures of the lever arrangement for opening and closing the circuit are fine, but one is enough since "if you've seen one you've seen 'em all" but the attachment arrangements of hooks and catches, of which there is great diversity, are considered unimportant by the average technical writer.  On Wikipedia the more things change the more they stay the same. How about some basic circuit breaker information and limit the technical verbosity on at least one page. Please.24.145.62.13 (talk) 23:30, 28 October 2009 (UTC)
replies: text: But an encyclopedia is not a catalog. Choosing the appropriate type of circuit breaker for a given application requires more expertise than can be reasonably put into an encyclopedia article. It is appropriate to talk about basic common principles here, not exhaustively list (as one of thousands of possible examples) which brands and models of miniature molded-case circuit breakers fit which brands and models of panel boards without violating UL approval. Which circuit breakers would you have us describe here - the 3 Amp one that protects a TV set, or the one that failed and blacked out an entire 230,000 kV service for a large city? You could easily fill a Wikipedia with circuit breaker descriptions, application guides, and outline drawings - but this is the job of the manufacturers, not of an encyclopedia. --Wtshymanski (talk) 20:05, 13 November 2009 (UTC)

text: User:okeos
The 400 KV image does not show any breaker or switchgeer.  It shows a small part of the 'visual indidicator of an open circut' which sits on both sides of a breaker.  When a breaker opens then on both sides rods open to provide a visual indication that the circuit is not currently engaged.   The Circut breaker for a 400KV line is much larger.  —Preceding unsigned comment added by 68.144.56.118 (talk) 11:09, 7 March 2010 (UTC)
thread_title:  More basic information needed by prospective users. 

message: When they can be fixed needs clarification. This seems to indicate drawout construction is really optional.  —Preceding unsigned comment added by 99.146.242.51 (talk) 18:02, 29 May 2010 (UTC)
thread_title:  Medium-voltage circuit breakers ... are often built with draw-out construction 

message: OK, am I just not getting something fundamental here, is it an esoteric sort of equation which needs further inline (or linked) explanation for a layman (i.e. the everyday wiki searcher) to understand, or it it an outright mistake?
The rating is described as being of the form "x/n", where x is determined by the rating (e.g. 2~3 for "B"), and, I can only assume, n is the breaker's normal rated current (ie long term sustained current).
Now what this means is, if I understand how this is written, for and within each of the classes - B, C, D, etc - the higher the sustained current rating, the lower the instantaneous tripping current, in a classical inverse relationship. E.G. for a B-class breaker, rated at 6A continuous, the ITC is between 0.333 and 0.5A (2-3/6, or 1/3-1/2). But one rated at 20A continuous has an ITC of only 0.1 to 0.15A (2/20-3/20...)
This surely can't be correct. So where's the misunderstanding/mistake? 193.63.174.10 (talk) 11:44, 30 September 2010 (UTC)
thread_title:  Instantaneous tripping current terminology / formula 

message: Please add a sample picture of the most common 15A/20A US circuit breakers. Please add the fact that 15A and 20A are the most common sizes of residential circuit breakers in the US. -96.233.19.191 (talk) 14:50, 11 July 2014 (UTC)
thread_title:  US 15A/20A most common breakers 

message: The "Instantaneous tripping current" section is too theoretical. 
We need a graph illustration like this one:
* www.bluesea.com/support/articles/Circuit_Protection/100/Fuse_Circuit_Breaker_Speed_Explained
:Speed Delay
:Opening speed, or delay, defines the relationship between the percentage by which the fuse or circuit breaker is operating over its Amperage Rating and the length of time that will be required for it to open. The opening of a fuse or circuit breaker is determined not just by the amperage rating, but by the amount of time and the percentage over its amperage rating at which it is being operated. The higher the % of current flow to amperage rating, the faster the circuit protector will open.
:A chart such as the one shown here commonly represents this relationship.
and text that both explains the general concept and gives a maximally relevant ordinary-case example. So if this graph did apply to a common US 20A circuit breaker, we would say that the breaker would be expected to pass up to at least 22A on a continuous basis, and would pass a surge of at least 60A for a tenth of a second without tripping, but could be expected to trip within 1-sec max at 40A. At 25A it might trip as quickly as half a sec, but might take up to about a half min.
And we should specifically mention "nuisance tripping", and explain that motors have short-term peak surge currents when they start, so circuit breakers are designed to not trip too quickly. -96.233.19.191 (talk) 16:39, 11 July 2014 (UTC)
thread_title:  trip speed 

message: I wish the USA's standards were described as well as internation ones. From the article: "In the United States, Underwriters Laboratories (UL) certifies equipment ratings, called Series Ratings (or “integrated equipment ratings”), using a two-tier rating. For example, a 22/10 rating. This rating means that the meter pack has a 22 kAIC tenant breaker, feeding a 10 kAIC loadcenter with 10 kAIC branches, where kAIC stands for “Thousand Ampere Interrupting Capacity.” Common meter pack ratings are 22/10, 42/10 and 100/10." 
As a engineer with a masters (not to boast, just for context), I can't understand this jargon at all. The reference http://www.claytonengineering.com/training/myweb6/Module11/Output/ImportantConcepts.html, is broken with no Google cache. What's a tenant breaker? What's a loadcenter?  — Preceding unsigned comment added by 169.231.82.57 (talk) 22:15, 18 February 2013 (UTC)
thread_title:  UL standards (USA) are confusing and lacking (with broken refs) 

message: how often do circuit breakers go bad themselves? Jeff Kizziar  01/03/15--71.32.95.26 (talk) 21:30, 3 January 2015 (UTC)
thread_title:  breakers 

message: why we cal circut breaker miniature?????Mohammadsdtmnd (talk) 12:58, 26 October 2015 (UTC)
thread_title:  miniature history 

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thread_title:  External links modified 

message: An analysis of the fire risks associated with circuit breakers?  One imagines that, certainly with high voltage applications, there is the potential for fires to start when the contact arcs of the circuit breaker damage the material out of which the circuit breaker is made.  Are circuit breakers lined with/made from flame re-tardant/flame proof materials?  Sorry if this is a silly question, but the article doesn't seem to mention the word 'fire' at all.  
ASavantDude (talk) 16:07, 10 March 2017 (UTC)
thread_title:  Electrical Fire Risks Associated with Circuit Breakers 

message: "By switching from SF6 to CO2 it is possible to reduce the CO2 emissions by 10 tons during the product's life cycle." This is a faithful reproduction of the source but I think it is misleading.  It probably means "greenhouse gas equivalent to 10 tons of CO2".  Comments please. Mock wurzel soup (talk) 00:31, 14 September 2019 (UTC)
thread_title:  Carbon dioxide (CO2) high-voltage 

message: What is the history of 63A rated circuit breakers? It seems like an odd number.  — Preceding unsigned comment added by 124.187.243.156 (talk) 02:57, 11 February 2022 (UTC)
thread_title:  Why 63, 630, 6300? 

message: The link to [magnetic blowout coils] about 3 pages into circuit breaker article mis-directs to something else (contactors). Tim Coahran (talk) 21:04, 25 June 2023 (UTC)
thread_title:  Typo found